Uterine fibroids in women diagnosed with acromegaly: a systematic review.

The review discusses the relationship between acromegaly and uterine fibroids. It highlights variations in research methodologies and inconsistent findings, emphasizing the complex nature of fibroid development and the role of the somatotropic axis. Additionally, it addresses demographic factors and examines the potential impact of therapies on the risk and prevalence of uterine fibroids in individuals with acromegaly. We conducted an analysis of previously published literature that examined the repercussions of acromegaly on gynecological health in female cohorts, with specific attention directed towards elucidating the prevalence of uterine fibroids. We suggest that larger, more focused studies are needed to understand the specific impact of different treatments on the occurrence of gynecological issues in acromegaly patients. Additionally, our study emphasizes the importance of factors such as disease duration and treatment effectiveness. We hypothesize that a relationship between acromegaly and uterine fibroids may occur. However, it remains an area of ongoing research, with the need for larger, multi-center studies to draw more definitive conclusions.

Evolution of the ecological niche behind the largest disjunct freshwater fish distribution in the world.

Ecological processes that are behind distributions of species that inhabit isolated localities, complex disjunct distributions, remain poorly understood. Traditionally, vicariance and dispersion have been proposed as explanatory mechanisms that drive such distributions. However, to date, our understanding of the ecological processes driving evolution of ecological niches associated with disjunct distributions remains rudimentary. Here, we propose a framework to deconstruct drivers of such distribution using World's most widespread freshwater fish Galaxias maculatus as a model and integrating marine and freshwater environments where its life cycle may occur. Specifically, we assessed ecological and historical factors (Gondwanan vicariance, marine dispersion) and potential dispersion (niche-tracking) that explain its distribution in the Southern Hemisphere. Estimated distribution was consistent with previously reported distribution and mainly driven by temperature and topography in freshwater environments and by primary productivity and nitrate in marine environments. Niche dynamics of G. maculatus provided evidence of synergy between vicariance and marine dispersion as explanatory mechanisms of its disjunct distribution, suggesting that its ecological niche was conserved since approximately 30 Ma ago. This integrated assessment of ecological niche in marine and freshwater environments serves as a generic framework that may be applied to understand processes underpinning complex distributions of diadromous species.

Los procesos ecológicos que subyacen a las distribuciones de especies que habitan en localidades aisladas, distribuciones disjuntas complejas, siguen siendo poco conocidos. Tradicionalmente, se han propuesto la dispersión y la vicarianza como mecanismos explicativos de tales distribuciones. Sin embargo, hasta la fecha, nuestra comprensión de los procesos ecológicos que impulsan la evolución de los nichos ecológicos de distribuciones disjuntas sigue siendo rudimentaria. Aquí proponemos un marco para de­construir los factores que impulsan dicha distribución, utilizando como modelo el pez de agua dulce con distribución más extendida del mundo, Galaxias maculatus, e integrando los entornos marinos y dulceacuícolas en los que se desarrolla su ciclo vital. En concreto, evaluamos los factores ecológicos e históricos (vicarianza gondwánica, dispersión marina) que explican su distribución en el hemisferio sur. La distribución estimada coincide con la descrita anteriormente para la especie y está determinada principalmente por la temperatura y la topografía en ambientes dulceacuícolas, y la productividad primaria y el nitrato en ambientes marinos. La dinámica de nicho de G. maculatus aportó pruebas de la sinergia entre vicarianza y dispersión marina como mecanismos explicativos de su distribución disjunta, lo que sugiere que su nicho ecológico se conservó desde hace aproximadamente 30 Ma. Esta evaluación integrada del nicho ecológico en ambientes marinos y dulceacuícolas puede aplicarse para comprender los procesos que subyacen a las distribuciones complejas de especies diádromas.

Species tree analyses and speciation-based species delimitation support new species in the relict catfish family Diplomystidae and provide insights on recent glacial history in Patagonia.

Diplomystidae is an early-diverged family of freshwater catfish endemic to southern South America. We have recently collected five juvenile specimens belonging to this family from the Bueno River Basin, a basin which the only previous record was a single juvenile specimen collected in 1996. This finding confirms the distribution of the family further South in northern Patagonia, but poses new questions about the origin of this population in an area with a strong glacial history. We used phylogenetic analyses to evaluate three different hypotheses that could explain the origin of this population in the basin. First, the population could have originated in Atlantic basins (East of the Andes) and dispersed to the Bueno Basin after the Last Glacial Maximum (LGM) via river reversals, as it has been proposed for other population of Diplomystes as well as for other freshwater species from Patagonia. Second, the population could have originated in the geographically close Valdivia Basin (West of the Andes) and dispersed south to its current location in the Bueno Basin. Third, regardless of its geographic origin (West or East of the Andes), the Bueno Basin population could have a longer history in the basin, surviving in situ through the LGM. In addition, we conducted species delimitation analyses using a recently developed method that uses a protracted model of speciation. Our goal was to test the species status of the Bueno Basin population along with another controversial population in Central Chile (Biobío Basin), which appeared highly divergent in previous studies with mtDNA. The phylogenetic analyses showed that the population from the Bueno Basin is more related to Atlantic than to Pacific lineages, although with a deep divergence that predated the LGM, supporting in situ survival rather than postglacial dispersal. In addition, these analyses also showed that the species D. nahuelbutaensis is polyphyletic, supporting the need for a taxonomic reevaluation. The species delimitation analyses supported two new species which are described using molecular diagnostic characters: Diplomystes arratiae sp. nov. from the Biobío, Carampangue, and Laraquete basins, maintaining D. nahuelbutaensis valid only for the Imperial Basin, and Diplomystes habitae sp. nov. from the Bueno Basin. This study greatly increases the number of species within both the family Diplomystidae and Patagonia, and contributes substantially to the knowledge of the evolution of southern South American freshwater biodiversity during its glacial history. Given the important contribution to the phylogenetic diversity of the family, we recommend a high conservation priority for both new species. Finally, this study highlights an exemplary scenario where species descriptions based only on DNA data are particularly valuable, bringing additional elements to the ongoing debate on DNA-based taxonomy.

Vulvar sebaceous hyperplasia - a problematic dermatosis of the vulva.

Sebaceous glandular hyperplasia (SGH) is a benign form of skin pathology, occurring in approximately one percent of the population. Risk factors for the SGH include advanced age, male sex, exposure to UV radiation and immunosuppression. The pathogenesis of SGH involves hormonal changes, is also regulated by insulin levels, thyroid stimulating hormone (TSH) and cortisol. SGH manifests itself as solitary or multiple light-yellow lumps, 2-3 mm big, with a smooth surface and a central umbilical depression. The vulvar localization of lesions is extremely rare and presents with a polymorphous clinical picture, posing a major diagnostic problem. A 40-year-old patient presented to the clinic due to vulvar skin lesions, periodically with the swelling of the labia and itching, with the symptoms deteriorating for approximately two years. The patient has been consulted by several doctors; however, the diagnosis has not been established. She did not receive adequate treatment either. On physical examination, attention was drawn to the overgrown labia minora - especially on the right side - with a network of abnormal vessels and numerous small papular lesions. SGH was diagnosed, based on the samples collected from the vulva. The patient was recommended isotretinoin therapy and referred to a dermatologist for a consultation. The presented case of vulvar SGH is interesting and rare. It is a diagnostic challenge with no established treatment standards. Nonetheless, SGH should be considered in the differential diagnosis of vulvar skin lesions. The comprehensive and interdisciplinary care is needed to help patients struggling with this insidious condition.

Molecular Biocompatibility of a Silver Nanoparticle Complex with Graphene Oxide to Human Skin in a 3D Epidermis In Vitro Model.

Silver nanoparticles (AgNP) can migrate to tissues and cells of the body, as well as to agglomerate, which reduces the effectiveness of their use for the antimicrobial protection of the skin. Graphene oxide (GO), with a super-thin flake structure, can be a carrier of AgNP that stabilizes their movement without inhibiting their antibacterial properties. Considering that the human skin is often the first contact with antimicrobial agent, the aim of the study was to assess whether the application of the complex of AgNP and GO is biocompatible with the skin model in in vitro studies. The conducted tests were performed in accordance with the criteria set in OECD TG439. AgNP-GO complex did not influence the genotoxicity and metabolism of the tissue. Furthermore, the complex reduced the pro-inflammatory properties of AgNP by reducing expression of IP-10 (interferon gamma-induced protein 10), IL-3 (interleukin 3), and IL-4 (interleukin 4) as well as MIP1ß (macrophage inflammatory protein 1ß) expressed in the GO group. Moreover, it showed a positive effect on the micro- and ultra-structure of the skin model. In conclusion, the synergistic effect of AgNP and GO as a complex can activate the process of epidermis renewal, which makes it suitable for use as a material for skin contact.

Unpacking the complexity of longitudinal movement and recruitment patterns of facultative amphidromous fish.

Longitudinal movement plays fundamental role in habitat colonization and population establishment of many riverine fish species. Movement patterns of amphidromous fish species at fine-scales that would allow characterizing the direction of movement and factors associated with the establishment of specific life-history strategies (resident or amphidromous) in rivers are still poorly understood. We assess fine-scale longitudinal movement variability patterns of facultative amphidromous fish species Galaxias maculatus in order to unfold its life-history variation and associated recruitment habitats. Specifically, we analyzed multi-elemental composition along core to edge transects in ear-bones (otoliths) of each fish using recursive partitions that divides the transect along signal discontinuities. Fine-scale movement assessment in five free-flowing river systems allowed us to identify movement direction and potential recruitment habitats. As such, resident recruitment of G. maculatus in freshwater (71%) and estuarine (24%) habitats was more frequent than amphidromous recruitment (5%), and was linked to availability of slow-flowing lotic or lentic habitats that produce or retain small-bodied prey consumed by their larvae. We postulate that life-history variation and successful recruitment of facultative amphidromous fish such as G. maculatus in river systems is driven by availability of suitable recruitment habitats and natural hydrologic connectivity that allows fish movement to these habitats.

The Effect of Vitamin E Supplementation in Postmenopausal Women-A Systematic Review.

Menopause is a physiological change in any woman. Nevertheless, its symptoms could be difficult to accept, and hormone therapy can be sometimes unattractive or contraindicated. Vitamin E components are phytoestrogens, so they are believed to be useful in some indications including menopause. This review aimed to assess the available evidence on the effectiveness of vitamin E in alleviating menopausal symptoms. The Pubmed/MEDLINE, Cochrane Library and Scopus databases were screened. All types of studies that assessed the effectiveness of vitamin E in alleviating menopausal symptoms were included. The PICO question was: "How does vitamin E supplementation affect menopausal symptom occurrence?" The PROSPERO ID number of this review is CRD42022328830. After quality assessment, 16 studies were included in the analysis. The studies were divided into three groups in which the influence of vitamin E on the genital syndrome of menopause, vasomotor symptoms and vascular and metabolic changes were assessed. Vitamin E influences postmenopausal hot flashes, vascular modulation, plasma lipid profile level and vaginal changes. Compared to vitamin E, estrogen administration leads to better clinical effects. Nevertheless, vitamin E might serve as additive to hormone therapy and its alternative in women with contraindications to estrogens. More quality data are necessary to draw final conclusions.

Stable isotope and fatty acid analyses reveal significant differences in trophic niches of smooth hammerhead Sphyrna zygaena (Carcharhiniformes) among three nursery areas in northern Humboldt Current System.

Fishery pressure on nursery areas of smooth hammerhead in northern Peruvian coast have become a serious threat to sustainability of this resource. Even though, some management actions focused on conservation of the smooth hammerhead populations were proposed in recent years, their scientific foundations are often limited, and biomass of smooth hammerhead in Peruvian waters continues to decrease. To inform management and conservation, this study aims to evaluate the trophic niche of smooth hammerhead juveniles from three nursery areas in the northern Peruvian coast using stable isotope and fatty acid analyses. First, we compared the environmental characteristics of each nursery area (i.e., sea surface temperature and chlorophyll-a concentration) and concluded that nursery areas differed significantly and consistently in sea surface temperature. Subsequently, we evaluated isotopic composition of carbon and nitrogen and fatty acid profiles of muscle and liver tissues collected from juvenile smooth hammerhead from each nursery area. We found that juvenile smooth hammerhead captured in San José were enriched in heavier 13C and 15N isotopes compared to those captured in Máncora and Salaverry. Furthermore, the broadest isotopic niches were observed in juveniles from Máncora, whereas isotopic niches of juveniles from Salaverry and San José were narrower. This difference is primarily driven by the Humboldt Current System and associated upwelling of cold and nutrient rich water that drives increased primary production in San José and, to a less extent, in Salaverry. Compared to smooth hammerhead juveniles from Máncora, those from San José and Salaverry were characterised by higher essential fatty acid concentrations related to pelagic and migratory prey. We conclude that smooth hammerhead juveniles from three nursery areas in the northern Peruvian coast differ significantly in their trophic niches. Thus, management and conservation efforts should consider each nursery area as a unique juvenile stock associated with a unique ecosystem and recognize the dependence of smooth hammerhead recruitment in San José and Salaverry on the productivity driven by the Humboldt Current System.

Effects of the cranial parasite Tylodelphys sp. on the behavior and physiology of puye Galaxias maculatus (Jenyns, 1842).

Diplostomatid digeneans are well-known manipulators of the behavior of their intermediate hosts. Unencysted metacercariae of Tylodelphys sp. inhabit the cranial cavity of the fish Galaxias maculatus; however, to date they have not been documented to alter their host behavior. The goal of this study was to evaluate the potential effects of Tylodelphys sp. inhabiting the cranial cavity of Galaxias maculatus on host physiology and swimming behavior as well as its reaction to a simulated predation attempt. Blind experiments in the lab were carried out on 56 fish that were filmed individually. The Fulton condition factor (K) was used as an approximation of nutritional status and a respirometry chamber was used to evaluate oxygen consumption rates of fish. Of the 56 fish, 21 were parasitized by Tylodelphys sp. (mean intensity = 30, range from 1 to 101). Parasitized and non-parasitized fish were similar in condition factor and oxygen consumption rates. Furthermore, the oxygen consumption rate of G. maculatus was not correlated with the abundance of Tylodelphys sp. However, parasitized fish more frequently swam close to the water surface, whereas non-parasitized fish more frequently swam at intermediate depths. When faced with a simulated predator attack, unparasitized fish showed more frequent fleeing behavior as well as a more intense post-fleeing activity. Collectively, these results suggest that Tylodelphys sp. inhabiting the cranial cavity of fish may alter their behavior predisposing them to predation by birds.

Interplay of geomorphology and hydrology drives macroinvertebrate assemblage responses to hydropeaking.

Hydropeaking leads to major anthropogenic disturbance of river networks worldwide. Flow variations imposed by hydropeaking may significantly affect macroinvertebrate assemblages within the river network. As such, the responses of macroinvertebrate assemblages to hydropeaking are expected to be complex and vary across spatial and temporal scales as well as ecological organization levels. To unpack this complexity, we assessed the interplay of geomorphic and hydrological variables as drivers of the responses of macroinvertebrate assemblages to hydropeaking. Specifically, we studied different levels of ecological organization of macroinvertebrate assemblages in two functional process zones (FPZs; Sub-Andean and Central Valley Gravel Dominated) subjected to different flow management in two Chilean Andean river networks. Hydropeaking caused significant reduction of macroinvertebrate abundances in both FPZs and at all ecological organization levels with the exception of one feeding guild (scrapers). Furthermore, the response of macroinvertebrate assemblage variance was stronger in the Central Valley Gravel Dominated FPZ. Both geomorphic and hydrological variables influenced macroinvertebrate assemblage responses. However, the effects of the principal geomorphic variables operated at valley (meso) spatial scale and the main hydrological variables operated at the sub-daily (micro) temporal scale. Therefore, to minimise the effects of hydropeaking on macroinvertebrate assemblages, flow management should consider reduction of sub-daily variability. Furthermore, placement of new barriers should take into account not only their position within the river network but also their effects downstream that strongly depend on characteristics of river valley.

The longest fragment drives fish beta diversity in fragmented river networks: Implications for river management and conservation.

Connectivity plays a crucial role in maintaining the structural and functional attributes of river networks. Therefore, the loss of connectivity (fragmentation) alters the functioning and diversity patterns of the biota at local and regional scales. The global hydropower boom is one of the main drivers of river network fragmentation, with significant effects on the diversity of riverine biota. Analyses of beta diversity of fish assemblages in rivers with different degrees of fragmentation can give new insights into mechanisms that contribute to the responses of these assemblages to fragmentation. Here, fish beta diversity within six river networks of central Chile with different levels of fragmentation was studied to assess the responses of fish assemblages to fragmentation. A hypothesis of a significant effect of fragmentation on the beta diversity of native and non-native fish in riffles and pools was tested. This effect is expected to be modulated by both changes in environmental heterogeneity and direct obstruction of natural dispersal routes. Beta diversity based on variation of assemblage structure and environmental heterogeneity showed significant differences among river networks. Fish beta diversity showed a clear response to fragmentation in recently fragmented rivers. Specifically, the beta diversity of native fishes in pools and non-native fishes in riffles decreased with increase of the ratio between the longest non-fragmented sections of the river network to the total length of the network. These effects of fragmentation on fish assemblages were modulated by the biological features of each species, and open-water species were most severely affected. These results have significant implications for planning of the placement of new barriers in river networks subjected to hydropower boom. Planning of the placement of new barriers should consider the maintenance of long, connected sections within river networks in order to minimise the effects of fragmentation on fish biodiversity.

Hydrological connectivity drives longitudinal movement of endangered endemic Chilean darter Percilia irwini (Eigenmann, 1927).

Movement is a fundamental aspect of fish ecology, and it therefore represents an important trait to monitor for the management and conservation of fish populations. This is especially true for small benthic fish, as they often inhabit part of the catchment where their movement may be restricted by alterations to river connectivity due to human activity. Still, the movement of these small benthic fish remains poorly understood, partly because of their small size and their cryptic nature. This applies to Percilia irwini, an endangered small darter native to the south-central region of Chile. Its habitat has been affected by the presence of large hydroelectric dams and is currently threatened by the construction of several others. In this study, the authors investigated movement patterns of P. irwini from populations inhabiting different parts of the Biobío catchment, with different levels of connectivity due to natural and/or human-induced features. The authors combined chronological clustering with random forest classification to reconstruct lifelong movements from multi-elemental otolith microchemistry transects. The majority of the movements detected occurred in an undisturbed part of the catchment. These were directional upstream movements occurring between capture sites from the lower and the middle reaches of the river, representing a distance of nearly 30 km, a distance much larger than previously thought. Nonetheless, in the part of the catchment where connectivity was affected by human activity, no such movements were identified. This study shows that connectivity alteration could impede naturally occurring movement and further threaten the resilience of populations of P. irwini. Furthermore, the results presented are used to discuss advantages and disadvantages of microchemistry analysis for studying movement of small benthic fish.

High Trophic Niche Overlap between a Native and Invasive Mink Does Not Drive Trophic Displacement of the Native Mink during an Invasion Process.

The pressure elicited by invasive species on native species significantly increases with the increase of the overlap of their ecological niches. Still, the specific mechanisms of the trophic displacement of native species during the invasion process are unclear. The effects of the invasive American mink (Neovison vison) on the critically endangered European mink (Mustela lutreola) was assessed by analyses of diet and niche overlap during the invasion process. To do this, the isotopic composition (δ13C and δ15N) of both species of mink and their four main types of prey was analysed. Significant trophic overlap between the native European mink and invasive American mink was found when they coexisted in sympatry. Furthermore, both mink species were characterised by significant individual variation in diet and no obvious change in diet of the native species in response to the arrival of the introduced species was observed. High niche overlap registered between both species in sympatry with no displacement in diet of the native mink in response to the arrival of the invasive mink is expected to have important consequences for the viability and conservation of the native mink populations, as it suggests high competitive pressure.

Functional response of fish assemblage to multiple stressors in a highly regulated Mediterranean river system.

Mediterranean rivers are characterised by strong environmental constrains and species-poor, highly endemic fish fauna. In Europe, these systems are exposed to multiple stressors due to extensive human activities. Studies on the effects of some stressors on riverine fish are available but complex responses of fish assemblages to interplay of flow alteration with physical habitat changes and invasive species have not been evaluated up to date. This study analysed the response of functional diversity of fish assemblages to multiple stressors in the Segura River system in the southern Spain. Fish assemblages were sampled in 16 sites in two consecutive periods (2009-2010 and 2013-2015). Subsequently, we assessed the responses of functional specialisation, originality and entropy (based on nine functional traits and abundances) as well as species richness and abundance to interplay of flow regime alteration and ecological status, fragmentation as well as non-native species abundance across spatial and temporal scales. The governing role of flow regime in structuring fish assemblage was superimposed on physical habitat changes, water quality deterioration and fragmentation as well as the presence of non-native fish species. We found an increase of species richness and abundance but decrease of functional specialisation and originality in river reaches with high level of base flow and more stable hydrological conditions. Opposite pattern was observed in reaches with severe reduction of base flow and marked inversion in the seasonal pattern of high and low flows. We postulate that the use of tools that consider the functional identity of the species as method to assess the effects of environmental alterations on fish biodiversity could improve conservation measures for Mediterranean fish fauna. Furthermore, design flows that mimic natural flow regime patterns characteristic for Mediterranean rivers are a promising tool to provide environmental conditions that would favour native fish within the assemblage and benefit their conservation.

A Century after! Rediscovery of the ancient catfish Diplomystes Bleeker 1858 (Siluriformes: Diplomystidae) in coastal river basins of Chile and its implications for conservation

The ancient catfish family Diplomystidae, with seven species endemic to rivers of southern South America, represents one of the oldest branches of the diverse order Siluriformes. With most species endangered, new reports of these species become extremely valuable for conservation. Currently, it is assumed that Diplomystes species inhabit only Andean (large) basins, and that they are extinct from coastal (small) basins from which their presence have not been recorded since 1919. Here, we document new records of the family Diplomystidae in the Laraquete and Carampangue basins, two coastal basins from the Nahuelbuta Coast Range, Chile, with no previous reports. This finding represents the rediscovery of the genus in coastal basins in more than a Century. Based on analysis of mitochondrial DNA sequences, the collected specimens were found to be closely related to Diplomystes nahuelbutaensis from the Andean Biobío Basin, but sufficiently differentiated to suggest that coastal basin populations are a different management unit. These populations are important because, contrary to previous thoughts, they prove these catfish can survive in small river networks, providing unique opportunities for research and conservation. The conservation category of Critically Endangered (CE) is recommended for the populations from the Laraquete and Carampangue basins.(AU)

La familia de bagres Diplomystidae, con siete especies endémicas de ríos del sur de Sudamérica, es uno de los linajes mas antiguos del diverso orden Siluriformes. Al estar la mayoría de las especies amenazadas, nuevos registros de éstas son extremadamente valiosos para su conservación. Actualmente, se ha asumido que los Diplomystidos se distribuyen solo en cuencas Andinas (más grandes), y que sus especies estarían extintas en cuencas de menor tamaño como las costeras, sin registros desde 1919. En este trabajo documentamos la familia Diplomistidae en las cuencas de Carampangue y Laraquete, dos cuencas costeras de la Cordillera de Nahuelbuta, Chile, lo que representa el primer registro de esta familia en estas cuencas costeras. Además, este hallazgo representa el re-descubrimiento de la familia en cuencas costeras después de un siglo. Sobre la base de análisis de ADN mitocondrial, los especímenes colectados se relacionaron más cercanamente con poblaciones de la especie Diplomystes nahuelbutaensis presente en la cuenca del Biobío. Sin embargo, existen diferencias genéticas suficientes entre las poblaciones costeras y las del Biobío para justificar su separación como unidad de manejo distinta. Estas poblaciones costeras son importantes porque demuestran que los Diplomístidos pueden sobrevivir en cuencas de pequeño tamaño, ofreciendo oportunidades únicas para su investigación y conservación. Se recomienda la categoría de conservación En Peligro Critico de Extinción (CR) para las poblaciones de las cuencas Laraquete y Carampangue.(AU)

The effects of diadromy and its loss on genomic divergence: The case of amphidromous Galaxias maculatus populations.

Understanding the evolutionary mechanisms that affect the genetic divergence between diadromous and resident populations across heterogeneous environments is a challenging task. While diadromy may promote gene flow leading to a lack of genetic differentiation among populations, resident populations tend to be affected by local adaptation and/or plasticity. Studies on these effects on genomic divergence in nonmodel amphidromous species are scarce. Galaxias maculatus, one of the most widespread fish species in the Southern Hemisphere, exhibits two life histories, an ancestral diadromous, specifically, amphidromous form, and a derived freshwater resident form. We examined the genetic diversity and divergence among 20 estuarine and resident populations across the Chilean distribution of G. maculatus and assessed the extent to which selection is involved in the differentiation among resident populations. We obtained nearly 4,400 SNP markers using a RADcap approach for 224 individuals. As expected, collections from estuarine locations typically consist of diadromous individuals. Diadromous populations are highly differentiated from their resident counterparts by both neutral and putative adaptive markers. While diadromous populations exhibit high gene flow and lack site fidelity, resident populations appear to be the product of different colonization events with relatively low genetic diversity and varying levels of gene flow. In particular, the northernmost resident populations were clearly genetically distinct and reproductively isolated from each other suggesting local adaptation. Our study provides insights into the role of life history differences in the maintenance of genetic diversity and the importance of genetic divergence in species evolution.

Hypothalamic-pituitary GnRH/LH axis activity is affected by salsolinol in sheep during lactation: Effects of intracerebroventricular infusions of salsolinol and its antagonizing analogue.

The aim of the study was to test the hypothesis that salsolinol, a derivative of dopamine, is involved in the regulation of hypothalamic-pituitary gonadotropic (GnRH/LH) axis activity in lactating sheep. In the first experiment performed on sheep during the fifth week of lactation, a structural analogue of salsolinol (1-MeDIQ) was infused into the third brain ventricle (IIIv) to antagonize its action within the central nervous system (CNS). A push-pull perfusion of the infundibular nucleus/median eminence was performed simultaneously, and blood samples were collected from the jugular vein. In the second experiment, sheep received infusions of salsolinol into the IIIv, 48 hours after the weaning of their 8-week-old lambs. Blood samples were collected during the experimental periods, and the anterior pituitary (AP) tissue was dissected immediately after the end of the experiment. Perfusate GnRH concentration (experiment 1), plasma LH concentration (experiments 1 and 2), and relative LHß mRNA levels in the AP tissue (experiment 2) were assayed. Blocking of salsolinol action in the CNS of lactating sheep caused a significant (P < 0.001) decrease in the perfusate GnRH concentrations in comparison with controls. Treatment with 1-MEDIQ also significantly decreased (P < 0.001) the LH concentration in the blood plasma. In turn, salsolinol infused 48 hours after lamb weaning significantly (P < 0.001) increased plasma LH concentration, reflected in the significant (P < 0.05) increase in the amplitude of LH pulses in the treated sheep as compared to the control animals. There was no significant difference in the relative levels of LHß-subunit mRNA in the AP between control and salsolinol-infused sheep. The results lead to a conclusion that salsolinol affects the secretory activity of the GnRH/LH axis in sheep during lactation. Whether salsolinol infused into the IIIv evokes this stimulatory effect by itself or by modulation of other regulatory systems needs to be clarified.

Effects of salsolinol and its antagonistic analogue, 1-MeDIQ, on growth hormone release in nursing sheep.

Suckling induces a GH surge simultaneously to that of prolactin, so we tested whether salsolinol, a dopamine derivative (1-methyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline), participates in the regulatory process of GH secretion in lactating sheep. A series of intracerebroventricular (i.c.v.) infusions of salsolinol, in two doses, was performed in nursing sheep, without suckling, during the fifth week of lactation. In other suckling sheep, we infused i.c.v. a structural analogue of salsolinol-1-methyl-3,4-dihydroisoqinoline (1-MeDIQ), which is able to antagonize salsolinol's action. Intracerebroventricular treatment of nursing sheep with a lower dose of salsolinol (total 50 ng) significantly increased plasma GH concentration, as compared with the concentrations noted before the infusion and in nursing controls. A higher dose of salsolinol (total 5 micrograms) did not affect GH release significantly. Intracerebroventricular treatment with 1-MeDIQ (total 300 micrograms) significantly reduced basal GH release, not affecting a pattern of GH surge in response to suckling. In conclusion, salsolinol may affect the regulatory process of GH secretion in lactating sheep, but its role seems not to be major.

Effects of a structural analogue of salsolinol, 1-MeDIQ, on pituitary prolactin release and dopaminergic activity in the mediobasal hypothalamus in nursing sheep.

The prolactin release caused by salsolinol (a derivative of dopamine, DA) in rats could be prevented by its structural analogue 1-methyl-3,4-dihydroisoqinoline (1-MeDIQ). To study the participation of salsolinol in the neural stimulatory mechanism of prolactin release in lactating sheep, we tested whether 1-MeDIQ, acting at the central nervous system (CNS) level, would diminish basal prolactin release and reduce prolactin surge induced by suckling. A series of intracerebroventricular (icv) infusions of 1-MeDIQ (5 x 60 microg/60 microl/30 min, at 30-min intervals) were performed in nursing ewes (n=8) during the fifth week of lactation. Additionally, by combining these infusions with push-pull perfusion, we studied the concentration of dopaminergic components, i.e., salsolinol, DA and 3,4-dihydroxyphenylacetic acid (DOPAC) within the infundibular nucleus/median eminence (IN/ME) in four of the ewes. Treatment with 1-MeDIQ significantly (P<0.001) reduced either the basal prolactin release during the non-suckling period or the suckling-induced prolactin surge. Specifically, the suppressive effect occurred gradually, affecting both the duration and amplitude of the prolactin surge. In the control ewes, the perfusate salsolinol concentration increased significantly (P<0.001) during suckling, while in the ewes treated with 1-MeDIQ only vestigial amounts of this compound were found during the non-suckling period. No DA was detected in the perfusates collected from the IN/ME of control and 1-MeDIQ-treated groups and no significant differences were found in the DOPAC concentrations between these groups. In conclusion, 1-MeDIQ is able to inhibit prolactin secretion in lactating sheep, acting at the CNS level. In addition, one of the way of 1-MeDIQ action may be directed to the local salsolinol release within the mediobasal hypothalamus.

Differential endocrine response in rams to intracerebroventricular infusion of genistein.

The intracerebroventricular infusions of genistein (total 40 mug) were made in male sheep (November) to test its influence on melatonin, growth hormone (GH) and luteinizing hormone (LH) secretion. The analysis of the results encompassed 3 similar periods: before the infusion (afternoon hours) the first (evening hours) and the second (night hours) halves of the treatment. The night plasma concentration of melatonin in genistein-infused rams was significantly lower than that noted during the respective period in vehicle-infused rams. Plasma GH concentration increased significantly in both vehicle- and genistein-infused rams during the night hours, as compared with the concentrations noted during the afternoon and evening, however, genistein significantly stimulated the amplitude of GH pulses in these latter. The LH concentration was significantly lower during the second part of genistein treatment, than in vehicle-infused rams. The frequency and amplitude of LH pulses clearly tended to decrease following genistein infusion. In conclusion, genistein, acting at the central nervous system level in sexually active rams is able to reduce the secretion of melatonin and LH and has also a slight stimulatory effect on the amplitude of GH pulses.