Histopathological analysis of liver of the catfish Pimelodus maculatus in a tropical eutrophic reservoir from Southeastern Brazil

We described liver tissues of the long-whiskered catfish Pimelodus maculatus using histological techniques through structures stained with hematoxylin and eosin. A total of 21 adult individuals were collected using gill nets during the winter of 2012, in a eutrophic reservoir in Southeastern Brazil. The main aim was to characterize the tissues and eventual changes, since this organ has a notable sensitivity to changes in altered aquatic systems. The liver contains the exocrine pancreas (hepatopancreas) that have pancreatic cells arranged around a branch of the portal vein. The hepatocytes are diffuse and arranged in cords. Normal liver of P. maculatus have a continuous compact field of weakly eosinophilic, rounded hepatocytes with scattered islands of connective tissue that enclose the bile ducts and blood vessels. The organization of exocrine pancreatic tissues is similar to the acinar morphology of many teleosts. Histopathological alterations in liver were evaluated semi-quantitatively and based on the severity of the lesions. The alterations in each organ were classified in progressive stages of damage to the tissue. Six types of liver alterations were found: 1) cytoplasmic vacuolization; 2) congestion; 3) inflammatory infiltrated; 4) infiltration of adipocytes; 5) steatosis; 6) granuloma. Incidence of melanomacrophage centers were observed in the liver. However, we cannot directly associate such changes with the eutrophic conditions of the reservoir, because we have no available reference area to compare. These findings are a baseline contribution, which enables comparisons with similar fish species in other tropical aquatic systems in further studies.

Influence of feeding habits in the endocrine pancreas of insectivore bat Pteronotus personatus and nectarivore bat Anoura geoffroyi: A comparative stereological and immunohistochemical study.

Pteronotus personatus as an insectivore bat and has a diet that consists of a high protein diet, whereas the diet of Anoura geoffroyi, a predominantly nectarivore bat, is rich in simple sugars like sucrose, glucose and fructose. Considering that diet influences the activation of different pathways, which may influence morphological adaptations in the gastrointestinal system, the aim of this study was to compare the morphology of the endocrine pancreas in P. personatus and A. geoffroyi. For this, histological, stereological and immunohistochemical methods were used. In P. personatus, the average diameter of the pancreatic islet was 40.47µm±13.94, while in A. geoffroyi was 88.16µm±36.40. The total number of pancreatic islets in P. personatus was 26150±2346 and in A. geoffroyi was 15970±1666. In P. personatus, the volume density of the pancreatic islets was 3.4%± 2.6, whereas in A. geoffroyi the volume density was 6.1%±3.7. In addition, the immunodensity of the α, ß and δ cells, in P. personatus was 25.8%±11.9, 35.5%±13.5, 3.9%±0.7, respectively, and in A. geoffroyi was 33.10%±12.7, 55.08%±7.4, 6.2%±4.6, respectively. In conclusion, the results of this study indicate differences in the pancreatic weight/body, weight ratio, diameter and volume density of pancreatic islets and in immunodensity of the ß and α cells between both species, which have different dietary habits.

Histochemical and immunohistochemical study on endocrine cells (5HT, GAS, and SST) of the gastrointestinal tract of a teleost, the characin Astyanax bimaculatus.

Endocrine cells secrete hormones through the mucosa of the gastrointestinal tract (GIT) and act on the overall regulation of digestive processes such as nutrient absorption, gut motility and intestinal blood flow. This study aimed to determine regional distribution and frequency of endocrine cells secretory of serotonin (5-HT), somatostatin (SST) and gastrin (GAS) in the GIT of a small-bodied widespread characin Astyanax bimaculatus using histological, histochemical and immunohistochemical techniques. Fragments of the stomach and gut fixed for 8h in Bouin liquid were subjected to histological processing and immunohistochemical routine. For the histological analyses, the technique of staining with hematoxylin and eosin (HE) was used, whereas for the histochemical analyses Gomori's trichrome, periodic acid+Schiff (PAS) and Alcian blue pH 2.5 (AB) were used to further immunohistochemical processing. The stomach has a mucosa lined with a simple columnar epithelium with mucus-secreting cells; the glandular region (proximal and distal portions) has folds and pits, whereas the non-glandular region has pits only. The intestinal epithelium is simple with plain cylindrical grooved and goblet cells. The anterior region has thin folds with few goblet cells, and the posterior region with thick folds and many goblet cells. The regional distribution and frequency of endocrine cells varied across regions of the GIT with the stomach showing the highest amount of immunoreactive (IR) cells. Only the 5-HT was found in the stomach (epithelia and glands) and gut regions, with comparatively higher frequency in the stomach. SST-IR cells were found in the stomach (epithelia and gastric glands) with higher frequency in the glandular region, whereas GAS-IR were found in the gastric glands only. The stomach was the only organ to have all the three types of endocrine cells, indicating that this organ is the main site of digestion of food in this species.

Analysis of the expression of p53 during the morphogenesis of the gastroesophageal mucosa of Gallus gallus domesticus (Linnaeus, 1758).

Ontogenesis comprises a series of events including cell proliferation and apoptosis and resulting in the normal development of the embryo. Protein p53 has been described as being involved in the development of several animal species. The aim of this study was to analyze the expression of protein p53 during the morphogenesis of the gastroesophageal mucosa of Gallus gallus domesticus and to correlate it with the histogenesis of structures present in this tissue. We used 24 embryos (at 12-20 days of incubation) and the thymus of two chickens. Immunohistochemical analysis was performed with the ABC indirect method. The expression of p53 in the gastroesophageal mucosa increased during the formation of the organ, mainly at the stages during which tissue remodeling and cell differentiation began. In the esophagus at stages 42 and 45, we observed immunoreactive (IR) cells in the surface epithelium and in early esophageal glands. In the proventriculus at stages 39-45, IR cells were present in the epithelial mucosa and rarely in the proventricular glands. In the gizzard after stage 42, we found IR cells mainly in the medial and basal epithelial layers of the mucosa and especially within the intercellular spaces that appeared at this phase and formed the tubular gland ducts. Thus, protein p53 occurs at key stages of development: in the esophagus during the remodeling of esophageal glands, in the proventriculus during the differentiation of the epithelium of the mucosa and in the gizzard during the formation of tubular glands.

Histologia e histoquímica do tubo digestório de Phrynops geoffroanus (Testudines, Chelidae) / Histology and histochemistry of the digestive tract of Phrynops geoffroanus (Testudines, Chelidae)

Phrynops geoffroanus is the omnivorous chelonian with widest geographical distribution in South America. This work describes the histology and histochemistry of the digestive tube of this species, to relate the characteristics of these organs to the species' eating habit. The esophagus, stomach and intestine of four specimens were fixed in 10% formal and embedded in paraffin by routine histological techniques. Afterwards, 5-µm sections were stained with hematoxylin-eosin (HE), periodic acid-Schiff (PAS) and alcian blue (AB) pH 0.4 and 2.5. The tube is formed by the mucosa, submucosa, muscular and adventitia or serosa layers. The mucosa layer of the esophagus and stomach is lined with a simple cylindrical epithelium with mucus-secreting cells, where are intraepithelial glands inserted in the portion of the esophagus and gastric fossettes emptying into glands in the stomach. The stomach is divided into an anterior, middle and posterior region, according to the depth of the fossettes and the concentration of gastric glands. The intestine is lined by a simple cylindrical epithelium with striated boundaries and goblet cells and is divided into an anterior and posterior regions, according to the pattern of folds of the mucosa layer and the number of goblet cells. Reactivity to PAS and AB is observed in the entire tube. Smooth muscle fibers are present in mucosa layer of all the segments. The muscular layer is formed by two sub-layers of smooth muscle, except for the posterior stomach. This study will help understanding of the digestive physiology of P. geoffroanus and provide data for comparative analyzes with other turtles.

Phrynops geoffroanus é o quelônio onívoro com mais ampla distribuição geográfica na América do Sul. Este trabalho descreve a histologia e histoquímica do tubo digestório desta espécie, relacionando as características dos órgãos com seu hábito alimentar. O esôfago, estômago e intestino de quatro espécimes foram fixados em formol 10% e incluídos em parafina por técnica histológica de rotina. Depois, cortes de 5 µm de espessura foram corados com hematoxilina-eosina (HE), ácido periódico de Schiff (PAS) e alcian blue (AB) pH 0.4 e 2.5. O tubo é formado pelas camadas mucosa, submucosa, muscular e adventícia ou serosa. A mucosa do esôfago e do estômago é revestida pelo epitélio simples cilíndrico com células mucossecretoras, onde estão inseridas glândulas intraepiteliais na porção do esôfago e fossetas gástricas desembocando em glândulas no estômago. O estômago divide-se em anterior, médio e posterior, de acordo com a profundidade das fossetas e a concentração de glândulas gástricas. O intestino é revestido pelo epitélio simples cilíndrico com borda estriada e células caliciformes e divide-se em anterior e posterior, de acordo com o padrão de dobramentos da mucosa e o número de células caliciformes. Reatividade ao PAS e AB é observada em todo o tubo. Fibras musculares lisas estão presentes na camada mucosa de todos os segmentos. A camada muscular é formada por duas subcamadas de músculo liso, exceto na porção posterior do estômago. Este estudo ajudará no entendimento da fisiologia digestiva da espécie investigada e fornecerá dados para análises comparativas com outros quelônios.

Morfologia do epitélio intestinal de codornas japonesas alimentadas com parede celular da Saccharomyces cerevisiae / Morphology of the intestinal epithelium of Japanese quail fed with cell wall Saccharomyces cerevisiae

Objetivou-se com este trabalho avaliar os benefícios e o melhor nível de inclusão de parede celular de Saccharomyces cerevisiae (PCSC) na dieta sobre a morfologia intestinal de codornas japonesas (Coturnix coturnix japonica) durante a fase de produção. 400 codornas japonesas (42 a 154 dias de idade) foram distribuídas em delineamento inteiramente casualizado, com cinco tratamentos e 10 repetições com oito aves cada. Foram utilizadas cinco dietas com diferentes níveis de parede celular de S. cerevisiae (0, 0,5, 1,0; 1,5; 2,0kg t-1). A dieta foi fornecida ad libitum durante todo o período experimental. As variáveis analisadas foram: altura e largura das vilosidades, relação altura/largura das vilosidades e profundidade da cripta intestinal. Altura, largura e proporção altura/largura das vilosidades intestinais foram influenciados pela inclusão de PCSc na dieta, enquanto que a profundidade das criptas não foi influenciada pela adição de PCSc. A inclusão de parede celular de S. cerevisiae na dieta até 1,7kg t-1 trouxe alterações positivas na morfologia do epitélio intestinal de codornas japonesas (C. c. japonica) na fase de produção.

Objective of this research was to evaluate the benefits and the best level of cell wall of Saccharomyces cerevisiae (PCSc) added on the diet, on intestinal morphology of Japanese quail (Coturnix coturnix japonica), during the production phase. 400 Japanese quails (42 to 154 days of age), were distributed in a complete random design, with five treatments and 10 replicates with 8 birds each. It was used five diets with different levels of cell wall of S. cerevisiae (0; 0.5; 1.0; 1.5; 2.0kg t-1). Diet was fed ad libitum during all the experimental period. The variables were: height and width of the villus, width / height ratio of the villi and depth of the intestinal crypt. Height, width and height and width ratio of the intestinal villi were influenced by the inclusion of PCSc in the diet, while the crypt depth was not influenced by the addition of PCSc. The inclusion of the cell wall of S. cerevisiae in the diet up to 1.7kg t-1 brought positive changes in the morphology of the intestinal epithelium of Japanese quail (C. c. japonica) in the production phase.

Histological description of morphogenesis of the gastroesophageal mucosa of gallus gallus domesticus (linnaeus, 1758) / Descripción histológica de la morfogénesis de la mucosa gastroesofágica de gallus gallus domesticus (linnaeus, 1758)

The ontogenesis of the gastroesophageal mucosa involves morphological alterations related to its structure and the function of each segment. The present study describes the histogenesis of the mucus-secreting epithelium and glands of the esophagus, gizzard, and proventriculus of the chicken (Gallus gallus), and identifies alterations in the secretion pattern of glycosaminoglycans (GAG's). We analyzed 38 chicken embryos, processed the material collected following the histological routine, and then stained it with hematoxylin-eosin for the analysis of tissue structure and with Gomori's trichrome for the identification of conjunctive tissue and collagen fibers. We used the PAS histochemical technique for the analysis of neutral GAG's and the AB pH 2.5 histochemical technique for the analysis of acid GAG's. The embryos at late stage of development had the esophagus wall composed of four layers: mucosa, submucosa, muscularis, and serosa, whereas the proventriculus and the gizzard were composed of three layers: mucosa, muscularis, and serosa. In all three segments, we identified the superficial epithelium as mucus-secreting; in the esophagus this epithelium was mucus-secreting only at the initial development stages. The proventricular glands began to form at the initial development stages, whereas the tubular glands began to form in the gizzard just after the 15th day. The differences in the production of GAG's in these regions of the digestive tract are related to development stages, functions, and physiological requirements of each segment, and to the gradual adjustment of the body to the post-hatching life.

La morfogénesis de la mucosa gastroesofágica implica alteraciones morfológicas relacionadas con su estructura y la función de cada segmento. El presente estudio describe la histogénesis del epitelio secretor mucinoso y de las glándulas del esófago, molleja y proventrículo del pollo (G. gallus), ademas de identificar los cambios em el patrón de secreción de glicocosaminoglicanos (GAG's). Se utilizaron treinta y ocho embriones de pollo. El material recogido fue procesado de acuerdo a la rutina histológica y posteriormente las secciones se tiñieron con hematoxilina-eosina para su análisis histológico, con tricrómico de Gomori para identificar el tejido conectivo y las fibras de colágeno y con PAS y AB pH 2,5 para el análisis GAG's neutro y ácido. En una etapa avanzada de desarrollo de los embriones, se pudo obervar en la pared del esófago cuatro capas: mucosa, submucosa, muscular y serosa, mientras que el proventrículo y molleja se muestra constituida por tres capas: mucosa, muscular y serosa. En los tres segmentos de la superficie, el epitelio se identificó como mucinoso y en el esófago sólo en la etapa inicial de desarrollo. Las glándulas del proventrículo se empiezan a formar en las primeras etapas de desarrollo, mientras que en las glándulas tubulares de la molleja comienzan su sólo después del día 15. Las diferencias en la producción de GAG's en estas regiones del tracto digestivo están relacionadas con las etapas de desarrollo, las funciones y necesidades fisiológicas de cada segmento del cuerpo y se adapta gradualmente a la vida después de la eclosión.

Histological and immunohistochemical study of the thyroid gland of the broad-snouted caiman (Caiman latirostris) / Estudo histológico e imuno-histoquímico da glândula tireoide do jacaré do papo-amarelo (Caiman latirostris)

The broad-snouted caiman, Caiman latirostris, is widely distributed in countries of South America. In Brazil it is considered an endangered species because of natural habitat destruction and illegal hunting. In reptiles, the thyroid gland plays an integral part in ecdysis, reproduction, tail regeneration, growth, endocrine function and metabolism rate. The aim of the present study was to characterize the thyroid gland morphology of C. latirostris, based on histochemical and immunohistochemical techniques. The thyroid glands were fixed in Bouin's fluid and serial cross sections were stained with hematoxylin-eosin, Mallory's trichrome, periodic acid-Schiff (PAS) and Alcian blue (AB pH 1.5 and 2.5). The immunohistochemical technique for 5-HT-IR cells was used. The thyroid gland has a dense irregular connective tissue forms a capsule enveloping the gland. There are several follicular acini of varying size lined by simple cuboidal or columnar epithelium in the thyroid gland. The follicles are connected by interfollicular connective tissue which contains blood vessels. We observed the presence of lymph nodes around the entire gland. There was a positive PAS reaction and negative AB reaction in the colloid. 5-HT-IR cells were detected around the follicle cells. No striking morphological differences were observed between C. latirostris and other domesticated mammals.

O jacaré do papo-amarelo, Caiman latirostris, é amplamente distribuído nos países da America do Sul. No Brasil este é considerado uma espécie em extinção pela destruição de seu habitat natural e caça ilegal. Em répteis, a glândula tireoide desempenha um papel fundamental na ecdise, reprodução, regeneração da cauda, crescimento, função endócrina e na taxa de metabolismo. O objetivo do estudo foi caracterizar a morfologia da glândula tireoide de C. latirostris, com base em técnicas de histoquímica e imuno-histoquímica. As tireoides foram fixadas em Bouin e seções transversais corados com hematoxilina-eosina, Tricrômico de Mallory, ácido periódico de Schiff (PAS) e Alcian blue (AB pH 1,5 e 2,5). A técnica de imuno-histoquímica para detecção de células imunoreativas a 5-HT foi utilizada. A glândula tireoide possui uma cápsula de tecido conjuntivo denso não modelado. Há numerosos ácinos foliculares de tamanho variáveis revestidos por epitélio cúbico ou cilíndrico simples. Entre os folículos observa-se o tecido conjuntivo ricamente vascularizado. Observamos a presença de linfonodos ao redor de toda a glândula. No coloide observou-se uma reação PAS positiva e AB negativa. Células imunoreativas para 5-HT foram detectadas em torno das células foliculares. Não foram observadas diferenças histológicas marcantes na tireoide de C. latirostris quando comparadas a outros mamíferos domésticos.

Histological and immunohistochemical study of the thyroid gland of the broad-snouted caiman (Caiman latirostris) - doi: 10.4025/actascibiolsci.v35i4.18444

The broad-snouted caiman, Caiman latirostris, is widely distributed in countries of South America. In Brazil it is considered an endangered species because of natural habitat destruction and illegal hunting.  In reptiles, the thyroid gland plays an integral part in ecdysis, reproduction, tail regeneration, growth, endocrine function and metabolism rate. The aim of the present study was to characterize the thyroid gland morphology of C. latirostris, based on histochemical and immunohistochemical techniques. The thyroid glands were fixed in Bouin"s fluid and serial cross sections were stained with hematoxylin-eosin, Mallorys trichrome, periodic acid-Schiff (PAS) and Alcian blue (AB pH 1.5 and 2.5). The immunohistochemical technique for 5-HT-IR cells was used. The thyroid gland has a dense irregular connective tissue forms a capsule enveloping the gland. There are several follicular acini of varying size lined by simple cuboidal or columnar epithelium in the thyroid gland. The follicles are connected by interfollicular connective tissue which contains blood vessels. We observed the presence of lymph nodes around the entire gland. There was a positive PAS reaction and negative AB reaction in the colloid. 5-HT-IR cells were detected around the follicle cells. No striking morphological differences were observed between C. latirostris and other domesticated mammals.

Immunohistochemical study of the digestive tract of Oligosarcus hepsetus.

AIM: To describe the histology of the digestive tract and to investigate the occurrence of endocrine cells in Oligosarcus hepsetus (O. hepsetus). METHODS: The digestive tract (DT) of O. hepsetus was divided into esophagus, two stomach regions (glandular and non-glandular) and two intestinal regions (anterior and posterior). These specimens were processed by routine histological techniques and stained with hematoxylin-eosin, Gomori's trichrome, periodic acid Schiff (PAS) and Alcian blue (AB). An immunohistochemical method using avidin-biotin-peroxidase was employed. RESULTS: The esophagus is lined with a non-keratinized stratified squamous epithelium that is reactive to PAS and AB. The stomach has a mucosa lined with a simple columnar epithelium with mucus-secreting cells that are reactive only to PAS. The intestine has a simple columnar epithelium with a brush border and goblet cells that are reactive to PAS and AB. Somatostatin, serotonin and cholecystokinin immunoreactive cells were identified throughout the DT. CONCLUSION: This study revealed adaptations for the species' diet and showed that the distribution and relative frequency of immunoreactive cells are similar to those of other fish.

What difference exists in the pancreas of mammals with sanguivorous diet? A morphological, stereological and immunohistochemical study of the pancreatic islets of the hematophagous bat Diphylla ecaudata.

Diphylla ecaudata is a vampire bat that mainly feeds on the blood of birds. This highly specialized diet - hematophagy - is accompanied by a series of morphological changes in the gastro-entero-pancreatic system, since the distribution and relative proportions of different pancreatic endocrine cell types can vary between species due to different physiological conditions and eating habits. The aim of this study was to examine for the first time the pancreas of the vampire bat D. ecaudata using morphological, stereological and immunohistochemical techniques. The pancreas of the D. ecaudata has an exocrine acinar portion in which the highest concentration of pancreatic islets is scattered. These pancreatic islets have irregular size and a mean diameter of 56.94 µm. The total number of islets in the pancreas was 23,900, with a volumetric density of 4.1%. Insulin-immunoreactive (IR) cells were located in the central pancreatic islet region and had the largest density (54.8%). Glucagon-IR cells were located mainly in the peripheral mantle region (16.2%), along with somatostatin-IR (SS) cells (14.3%). Cells immunoreactive to insulin, glucagon and somatostatin were also observed to have spread in isolated places in the exocrine pancreas. In the connective tissue near the pancreatic ducts, a high concentration was identified of insulin-IR cells and a low concentration of glucagon-IR and somatostatin-IR cells. These results indicate that although the pancreas of D. ecaudata has morphological similarities with that of other mammals, it has a differentiated islet structure, because there were a large number of islets and different volumetric densities of α, ß and δ cells.

Can fish gill anomalies be used to assess water quality in freshwater neotropical systems?

Gill anomalies in two fish species (Geophagus brasiliensis and Astyanax bimaculatus) were compared among three freshwater systems with different water quality: one eutrophic river, one eutrophic reservoir, and one oligotrophic reservoir. The raised hypotheses are that reservoirs with low water quality (eutrophic) have fish with more gills anomalies compared with reservoirs with high water quality (oligotrophic), and that the more stable environmental conditions of eutrophic rivers have fish with better healthy conditions than eutrophic reservoirs that have lesser stable environmental conditions. Gills of 36 adult individuals of G. brasiliensis and 23 of A. bimaculatus collected during the winter 2008 and winter 2009 were examined, and the proportions of occurrence of nine histological alterations were compared for the two species among the three systems using a binomial t test for independent samples. Histological changes in fish gills that are reversible and unspecific, such as epithelial lifting, interstitial edema, leukocyte infiltration, hyperplasia of the epithelial cells, lamellar fusion, and vasodilatation were common in both fish species in the three systems. However, lamellar aneurism, which is a more serious and often irreversible anomaly, and lamellar blood congestion occurred only in fish from the two reservoirs. Alternatively, necrosis occurred more in fish from the river. Fish gill anomalies in both species did not differ between the two reservoirs, despite having different water quality. We rejected the hypothesis that reservoirs with lower water quality have fish with more gill injuries compared with high water quality reservoirs. Moreover, the eutrophic river seems to affect differently the healthy condition of fish species, compared with the eutrophic reservoir.

Distributions of the endocrine cells in the gastrointestinal tract of nectarivorous and sanguivorous bats: a comparative immunocytochemical study.

The present study was conducted to clarify the influence of feeding habits on regional distribution and relative frequency of endocrine cells secreting cholecystokinin (CCK), gastrin (GAS), serotonin (5-HT) and enteroglucagon (GLUC) in the nectarivorous Anoura geoffroyi and Glossophaga soricina and the sanguivorous Desmodus rotundus bats of the Phyllostomidae family, by specific immunohistochemical methods. The regional distribution and frequency of the different types of endocrine cells varied according to their location in the GIT. 5-HT immunoreactive cells (IR), detected throughout the GIT of three bats, were the most predominant gastrointestinal endocrine cells. GAS-IR cells in A. geoffroyi were found at the base of the pyloric gland, while in G. soricina they could also be observed in the middle to basal portions of the gland. GLUC-IR cells were located in the fundic region of A. geoffroyi, G. soricina and D. rotundus. These endocrine cells were more abundant in the sanguivorous bat. In nectarivorous bats were compared to sanguivorous bat, which differ in dietary habits, difference in the distribution and relative frequency of gut endocrine cells would be predicted. The absence of some, and decrease in frequency of other, gastrointestinal endocrine cells may reflect, in part, its interspecies differences or dietary habits.

An immunocytochemical study of the endocrine cells in the stomach and duodenum of Zonotrichia capensis subtorquata (Passeriformes, Emberizidae).

The main purpose of this study was to evaluate the regional distribution pattern and relative frequency of some endocrine cells in the three portions of the gastrointestinal tract (GIT)--the proventriculus, gizzard and duodenum- of the rufous-collared sparrow (Zonotrichia capensis subtorquata), by immunohistochemical methods using six types of polyclonal antisera, specific for serotonin (5-HT), somatostatin (D cells), glucagon, motilin, polypeptide YY (PYY) and insulin. In the proventriculus, endocrine cells immunoreactive for all of these markers were observed. The somatostatin-immunoreactive cells were found with greater frequency, with the presence of cytoplasmic processes. In the gizzard, endocrine cells secreting somatostatin, 5-HT and PYY were detected, while those secreting glucagon and insulin were not. In the final part of the gizzard, endocrine cells secreting 5-HT were more frequent, and cells secreting somatostatin and insulin were not detected. All of the cell types studied were observed in the duodenum in different frequencies, except for cells immunoreactive for glucagon and insulin. The somatostatin-positive (D cells) were the most numerous, being more prevalent in the intestinal glands. The other endocrine cells were identified in smaller numbers, some of them located in the intestinal villi and Lieberkuhn glands. The finding of these cell types in the duodenum confirms their preferential location in the final portions of the principal segments of the digestive system and suggests control by feedback of its functions. In conclusion, some interesting distributional patterns of gastrointestinal endocrine cells were found in this species of sparrow.

A comparative immunohistochemical study of endocrine cells in the digestive tract of two frugivorous bats: Artibeus cinerius and Sturnira lilium.

The purpose of the present study was to examine the serotonin (5-hydroxytryptamine, 5-HT), gastrin (GAS), cholecystokinin (CCK) and glucagon (GLUC) endocrine cells in the gastrointestinal tract of frugivorous Phillostomidae bats, Sturnira lilium and Artibeus cinerius, to clarify the correlation between distribution of cell types and their relative frequency, with feeding habits. Five portions of the gastrointestinal tract--fundus, pilorus, and three parts of the intestine, I, II and III--were examined. Most of the immunoreactive cells in the stomach and intestine were of triangular, oval or piriform shape. Serotonin-immunoreactive cells were most commonly found in the S. lilium intestine I (66.6+/-9.9) and the A. cinerius intestine III (35+/-18). Gastrin-immunoreactive cells were the most abundant cell type in the pyloric glands of both species. They were more numerous in A. cinerius (126.9+/-27.4) than in S. lilium (75.8+/-1.8). CCK-immunoreactive cells were found in the alimentary tract epithelia at moderate frequencies in both species. GLUC-immunoreactive cells were detected at very low or low frequencies. This study suggests that there is a correlation between endocrine cell distribution and frequency, and the feeding habits of the bats.

Morphology of gonads, maturity and spawning season of Loricariichthys spixii (Siluriformes, Loricariidae) in a Subtropical Reservoir

The gonad morphology and spawning season of Loricariichthys spixii in Lajes reservoir were described based on 175 males and 613 females. Cells from the spermatogenic lineage were divided in four phases: spermatogonia (primary and secondary), spermatocytes (primary and secondary), spermatids and spermatozoa, and the cells from the ovocitarian lineage were divided in four phases: primary oocytes (O1), previtellogenic oocytes (O2), cortical vesicle oocytes (O3) and yolk globules or vitellogenic (O4). Five gonadal stages were described for the males/females according to oocytes and spermatogenic lineage cells distribution: resting (1); initial maturation (2a); advanced maturation (2b); partially spent/spawned (4a); totally spent/spawned (4b). Spawning was iteroparous, occurring throughout the year. Resting/recover occurred in July/August for the females coinciding with lower temperature and rainfall and decreasing water level. The wide spawning period was the part of the strategy developed to withstand environmental pressure and to get success in this oligotrophic and poorly structured environment.

A morfologia das gônadas e a época de desova de Loricariichthys spixii, no reservatório de Lajes foi descrita baseada em 175 machos e 613 fêmeas, coletados de Janeiro-1996 a Dezembro-1997. Células de linhagem espermatogênica foram divididas em 4 fases: espermatogônias (primárias e secundárias), espermatócitos (primários e secundários), espermátides e espermatozóides, enquanto as células de linhagem ovocitária também foram divididas em 4 fases, baseadas em características do núcleo, ooplasma e folículos dos ovócitos: ovócitos primários (O1), ovócitos previtelogênicos (O2), ovócitos de vesícula cortical (O3) e glóbulos de vitelo ou vitelogênicos (O4). Cinco estádios gonadais foram descritos para machos/fêmeas de acordo com a distribuição das células de linhagem ovocitária / espermatogênicas: repouso (1); maturação inicial (2a); maturação avançada (2b); parcialmente esvaziado/desovado (4a); totalmente esvaziado/desovado (4b). Desova é parcelada, ocorrendo através do ano. O repouso/recuperação ocorreu em Julho/Agosto para fêmeas coincidindo com menores temperaturas e pluviosidades, e diminuições do níveis da água. O amplo período reprodutivo é parte da estratégia desenvolvida por esta espécie para suportar as pressões ambientais (bióticas e abióticas) e obter sucesso neste reservatório oligotrófico e pobremente estruturado.

Correlação morfométrica do ovário de fêmeas bovinas em diferentes estádios reprodutivos / Morphometric correlation of the ovary of bovine females on different reproductive stages

Objetivou-se avaliar as características morfométricas de ovários recuperados de bovinos em diferentes estádios reprodutivos. Os ovários utilizados (N=200) foram obtidos em matadouro e transportados para o laboratório, onde foram realizadas as mensurações do tamanho do órgão, dos folículos e corpos lúteos. Os pares de ovários foram classificados em função do estádio reprodutivo, da fase do ciclo estral ou do período de gestação dos animais dos quais foram recuperados. Observou-se que o tamanho do ovário diferiu (P<0,001) entre os animais pré-púberes e pós-púberes. Não se observou diferença (P>0,05) no tamanho do órgão entre os animais apresentando AOLC ou gestantes, porém nestes o corpo lúteo foi maior e o diâmetro do maior folículo menor (P<0,05). Os parâmetros em estudo também foram afetados pela fase do ciclo estral (P<0,05) e pelo período da gestação (P<0,05). Nos animais com AOLC, observou-se uma correlação significativa entre o tamanho do ovário e o do corpo lúteo (R=0,69; P<0,01). Conclui-se que as características morfológicas do ovário variam em função do estádio reprodutivo, podendo ser utilizadas como parâmetro na avaliação clinica e funcional do órgão