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1.
J Fish Dis ; 39(3): 295-308, 2016 Mar.
Article in English | MEDLINE | ID: mdl-25865023

ABSTRACT

The aim of this study was the assessment of histological and hormonal changes induced in the European eel from environmental concentrations of cocaine. Silver eels were exposed to 20 ng L(-1) of cocaine during 50 days; at the same time, control, vehicle control and two post-exposure recovery groups (3 and 10 days) were made. The general morphology of the skin and the intestine, and the plasma levels of prolactin, cortisol and dopamine were evaluated. In the skin, cocaine decreased the number and size of mucous cells, increased the thickness of the epidermis and altered the club cells and the basal lamina. In the intestine, cocaine increased the thickness of the epithelium and the number of mucous cells and reactivated the structure of the intestine and of the intestinal musculature. Moreover, cocaine increased plasma prolactin, cortisol and dopamine levels. These results suggest that cocaine induced histological changes, directly and/or through the hormonal changes observed. Considering the complex life cycle of the eel, the changes induced by cocaine in the skin, the intestine and the endocrine system could threaten the ability of the eel to successfully migrate and reproduce.


Subject(s)
Anguilla , Cocaine/toxicity , Endocrine System/drug effects , Intestines/drug effects , Skin/drug effects , Water Pollutants, Chemical/toxicity , Animals , Dopamine/blood , Environmental Exposure , Hydrocortisone/blood , Prolactin/blood
2.
Toxicol In Vitro ; 29(7): 1436-44, 2015 Oct.
Article in English | MEDLINE | ID: mdl-25998160

ABSTRACT

4-Nonylphenol is a widely diffused and stable environmental contaminant, originating from the degradation of alkyl phenol ethoxylates, common surfactants employed in several industrial applications. Due to its hydrophobic nature, 4-nonylphenol can easily accumulate in living organisms, including humans, where it displays a wide range of toxic effects. Since the gastrointestinal tract represents the main route by which 4-nonylphenol enters the body, the intestine may be one of the first organs to be damaged by chronic exposure to this pollutant through the diet. In the present study, we investigated the effects of 4-nonylphenol on a human intestinal epithelial cell line (Caco-2 cells). We demonstrated that 4-nonylphenol was cytotoxic to cells, as revealed by a decrease of the cell number and the decrement of mitochondrial functionality after 24 h of treatment. 4-Nonylphenol also reduced the number of cells entering into S-phase and interfered with epidermal growth factor signalling, with consequent negative effects on cell survival. In addition, 4-nonylphenol induced apoptosis, involving the activation of caspase-3, and triggered an endoplasmic reticulum-stress response, as revealed by over-expression of GRP78 (78 kDa glucose-regulated protein) and activation of XBP1 (X-box binding protein-1). Together, these findings support the hypothesis that prolonged exposure to 4-nonylphenol through the diet may lead to local damage at the level of intestinal mucosa, with potentially negative consequences for intestinal homeostasis and functionality.


Subject(s)
Intestinal Mucosa/drug effects , Phenols/toxicity , Apoptosis/drug effects , Caco-2 Cells , Cell Survival/drug effects , DNA-Binding Proteins/metabolism , Endoplasmic Reticulum Chaperone BiP , Endoplasmic Reticulum Stress/drug effects , Heat-Shock Proteins/genetics , Heat-Shock Proteins/metabolism , Humans , Regulatory Factor X Transcription Factors , Transcription Factors/metabolism , X-Box Binding Protein 1
3.
J Assist Reprod Genet ; 31(10): 1269-76, 2014 Oct.
Article in English | MEDLINE | ID: mdl-25113619

ABSTRACT

PURPOSE: The purpose of this study was to evaluate the oxidative stress status (OS) of follicular fluid (FF) and the oocyte quality in women with polycystic ovary syndrome (PCOS) undergoing different ovarian stimulation protocols. METHODS: FF samples were collected after gonadotropin administration in association or not with metformin or D-chiro-inositol (DCI). OS status was then evaluated by checking the follicular fluid protein oxidation profile after specific labeling of aminoacidic free-SH groups, and two-dimensional electrophoresis followed by qualitative and semiquantitative analysis. Oocyte quality was assessed by international morphological criteria. RESULTS: Our data indicated that both treatments, even if to different extent, recovered a significantly high level of free-SH groups in FF proteins of PCOS women clearly indicating a decrease of OS level with respect to that found in FF samples from gonadotropins alone treated women. A higher number of good quality MII oocytes was also observed in DCI (P < 0.05) or metformin (P < 0.05) study groups in comparison to untreated control group. CONCLUSION: A natural supplement and a drug both showed a statistically significant positive effect on follicular milieu by decreasing the oxidative damage on FF proteins, as well as in recovering good quality oocytes.


Subject(s)
Biomarkers/metabolism , Inositol/therapeutic use , Metformin/therapeutic use , Oxidative Stress/drug effects , Polycystic Ovary Syndrome/drug therapy , Protein Processing, Post-Translational/drug effects , Adult , Female , Fertilization in Vitro/methods , Follicular Fluid/drug effects , Follicular Fluid/metabolism , Gonadotropins/therapeutic use , Humans , Oocytes/drug effects , Oocytes/metabolism , Ovulation Induction/methods , Oxidative Stress/physiology , Polycystic Ovary Syndrome/metabolism , Protein Processing, Post-Translational/physiology
4.
J Proteomics ; 90: 61-76, 2013 Sep 02.
Article in English | MEDLINE | ID: mdl-23500131

ABSTRACT

Human follicular fluid (HFF) has been proven to contain biologically active molecules and proteins that may affect follicle growth and oocyte fertilization. Based on this concept, HFF proteomic characterization is having a significant impact in the delineation of a biomarkers' profile for oocyte quality estimation and, maybe, for in vitro fertilization (IVF) success improvement. Follicular fluid is characterized by a vast protein complexity and a broad dynamic range of protein abundances that hinder its analysis. In this study we determined a proper solubilization and resolution method of HFF in 2-DE, minimizing sample manipulation, protein loss, and experimental artifacts. According to our methodology some low-abundance proteins were detected and identified by MS. Identified proteins were then functionally cross-linked by a pathway analysis. The generated path highlighted the occurrence in HFF of a tight functional-network in which effectors and inhibitors control and balance a space- and time-dependent induction/inhibition of inflammation, coagulation, and ECM degradation/remodeling. Such fine modulation of enzymatic activities exerts a fundamental role in follicle development and in oocyte competence acquiring. Alpha-1-antitrypsin resulted in the core protein of the delineated net and we interestingly detected its differential incidence in FF and serum from two small cohorts of patients who underwent IVF. BIOLOGICAL SIGNIFICANCE: Human ovarian follicular fluid (HFF) is the in vivo microenvironment for oocyte during folliculogenesis. It contains biologically active molecules that may affect oocyte quality, fertilization, and embryo development. HFF is also one of the most abundant "waste product" in assisted reproduction. This makes HFF a readily accessible source of biomolecules for competence evaluation of collected oocytes. The methodological improvement we obtained in proteomics characterization of HFF lead to a wide overview on the functional correlation existing between several fluid components and on how their aberrant occurrence/activity may affect oocyte quality and ovulation.


Subject(s)
Follicular Fluid/metabolism , Proteome/metabolism , Proteomics/methods , Adult , Biomarkers/chemistry , Biomarkers/metabolism , Female , Follicular Fluid/chemistry , Humans , Proteome/chemistry
5.
Ecotoxicology ; 20(4): 885-91, 2011 Jun.
Article in English | MEDLINE | ID: mdl-21461776

ABSTRACT

The increasing use of pesticides in modern agriculture has raised the need to evaluate their potential threat to animal and human health. In the present study, the genotoxic effects of environmentally relevant exposure to the fungicide thiophanate-methyl (TM) were assessed in the lizard Podarcis sicula (Reptilia, Lacertidae) using micronucleus test, chromosome aberration analysis and single-cell gel electrophoresis (comet) assay. The number of micronuclei increased significantly with exposure time in lizard specimens exposed to 1.5% TM for 30-40 days. In situ hybridization with the specific HindIII centromeric satellite was positive in 18.7% of the micronuclei observed, suggesting an aneugenic effect of TM during mitosis. DNA damage, evaluated by the comet assay, documented a significant gain in comet length in relation to exposure time that was paralleled by a reduction in head size. Finally, cytogenetic analysis showed a significant increase in chromosome aberrations in exposed animals compared with controls. Our data suggest that long-term TM exposure induces a genomic damage that is positively correlated to exposure time. If such genotoxic effects arise so clearly in an ectothermal vertebrate, such as P. sicula, prolonged exposure TM must be considered as a cytogenetic hazard.


Subject(s)
Fungicides, Industrial/toxicity , Lizards/physiology , Mutagens/toxicity , Thiophanate/toxicity , Animals , Chromosome Aberrations/chemically induced , Comet Assay , Micronucleus Tests
6.
J Morphol ; 262(3): 692-700, 2004 Dec.
Article in English | MEDLINE | ID: mdl-15487003

ABSTRACT

The influence of adrenocorticotropic hormone (ACTH) on the interrenal gland of Triturus carnifex was investigated by in vivo administration of synthetic ACTH. The effects were evaluated by examination of the ultrastructural morphological and morphometrical features of the tissues as well as the circulating serum levels of aldosterone, noradrenaline (NA), and adrenaline (A). In June and November, ACTH administration increased aldosterone release (from 281.50 +/- 1.60 pg/ml in carrier-injected newts to 597.02 +/- 3.35 pg/ml in June; from 187.45 +/- 1.34 pg/ml in carrier-injected animals to 651.00 +/- 3.61 pg/ml in November). The steroidogenic cells showed clear signs of stimulation, together with a reduction of lipid content in June and an increase of lipid content in November. Moreover, ACTH administration decreased the mean total number of secretory vesicles in the chromaffin cells in June (from 7.73 +/- 0.60 granules/microm2 in carrier-injected animals to 5.91 +/- 0.40 granules/microm2) and November (from 7.78 +/- 0.75 granules/microm2 in carrier-injected newts to 4.87 +/- 0.40 granules/microm2). In June, however, when T. carnifex chromaffin cells contain almost exclusively NA granules (NA: 7.42 +/- 0.86 granules/microm2; A: 0.32 +/- 0.13 granules/microm2), ACTH decreased NA content (5.52 +/- 0.32 granules/microm2) increasing NA release (from 639.82 +/- 3.30 pg/ml in carrier-injected to 880.55 +/- 4.52 pg/ml). In November, when both catecholamines, NA (3.92 +/- 0.34 granules/microm2) and A (3.84 +/- 0.33 granules/microm2), are present in the chromaffin cells, ACTH administration reduced A content (1.02 +/- 0.20 granules/microm2), enhancing adrenaline secretion (from 681.30 +/- 3.62 pg/ml in carrier-injected newts to 1,335.73 +/- 9.03 pg/ml). The results of this study indicate that ACTH influences the steroidogenic tissue, eliciting aldosterone release. The effects on the chromaffin tissue, increase of NA or A secretion, according to the period of chromaffin cell functional cycle, may be direct and/or mediated through the increase of aldosterone release. Finally, the lack of an increase of A content in the chromaffin cells, or A serum level, following ACTH administration in June might suggest an independence of PNMT enzyme on corticosteroids.


Subject(s)
Adrenocorticotropic Hormone/administration & dosage , Aldosterone/metabolism , Catecholamines/metabolism , Interrenal Gland/metabolism , Triturus/physiology , Animals , Interrenal Gland/drug effects , Interrenal Gland/ultrastructure , Male , Triturus/anatomy & histology
7.
J Morphol ; 261(1): 18-25, 2004 Jul.
Article in English | MEDLINE | ID: mdl-15164364

ABSTRACT

The existence of paracrine control of steroidogenic activity by adrenochromaffin cells in Triturus carnifex was investigated by in vivo adrenaline (A) administration. The effects were evaluated by examination of the ultrastructural morphological and morphometrical features of the tissues as well as the serum levels of aldosterone, noradrenaline (NA), and adrenaline. In March and July, adrenaline administration reduced aldosterone release (from 187.23 +/- 2.93 pg/ml to 32.28 +/- 1.85 pg/ml in March; from 314.60 +/- 1.34 pg/ml to 87.51 +/- 2.57 pg/ml in July) from steroidogenic cells. The cells showed clear signs of lowered activity: they appeared full of lipid, forming large droplets. Moreover, adrenaline administration decreased the mean total number of secretory granules in the chromaffin cells in July (from 7.74 +/- 0.74 granules/microm(2) to 5.14 +/- 1.55 granules/microm(2)). In this period T. carnifex chromaffin cells contain almost exclusively NA granules (NA: 7.42 +/- 0.86 granules/microm(2); A: 0.32 +/- 0.13 granules/microm(2)). Adrenaline administration reduced noradrenaline content (4.36 +/- 1.40 granules/microm(2)) in the chromaffin cells, enhancing noradrenaline secretion (from 640.19 +/- 1.65 pg/ml to 1030.16 +/- 3.03 pg/ml). In March, adrenaline administration did not affect the mean total number of secretory vesicles (from 7.24 +/- 0.18 granules/microm(2) to 7.25 +/- 1.97 granules/microm(2)). In this period the chromaffin cells contain both catecholamines, noradrenaline (3.88 +/- 0.13 granules/microm(2)), and adrenaline (3.36 +/- 0.05 granules/microm(2)), in almost equal quantities; adrenaline administration reduced adrenaline content (1.74 +/- 0.84 granules/microm(2)), increasing adrenaline release (from 681.27 +/- 1.83 pg/ml to 951.77 +/- 4.11 pg/ml). The results of this study indicate that adrenaline influences the steroidogenic cells, inhibiting aldosterone release. Adrenaline effects on the chromaffin cells (increase of noradrenaline or adrenaline secretion) vary according to the period of chromaffin cell functional cycle. The existence of intraadrenal paracrine interactions in T. carnifex is discussed.


Subject(s)
Chromaffin Cells/metabolism , Endocrine Glands/physiology , Epinephrine/administration & dosage , Secretory Vesicles/metabolism , Aldosterone/blood , Animals , Chromaffin Cells/ultrastructure , Endocrine Glands/drug effects , Endocrine Glands/ultrastructure , Epinephrine/blood , Male , Microscopy, Electron, Transmission , Norepinephrine/blood , Salamandridae , Secretory Vesicles/ultrastructure
8.
J Morphol ; 259(1): 33-40, 2004 Jan.
Article in English | MEDLINE | ID: mdl-14666523

ABSTRACT

The existence of paracrine control of steroidogenic activity by adrenochromaffin cells in Triturus carnifex was investigated by in vivo noradrenaline (NA) administration. The effects were evaluated by examination of the ultrastructural morphological and morphometrical features of the tissues as well as the serum levels of aldosterone, NA, and adrenaline (A). In March and July, NA administration increased aldosterone release (from 187.23 +/- 2.93 pg/ml to 878.31 +/- 6.13 pg/ml in March; from 314.60 +/- 1.34 pg/ml to 622.51 +/- 2.65 pg/ml in July) from steroidogenic cells. The cells showed clear signs of stimulation, as evidenced by a strong reduction of lipid content. Moreover, NA administration decreased the mean total number of secretory vesicles in the chromaffin cells in March (from 7.24 +/- 0.18 granules/micro2 to 5.57 +/- 1.88 granules/micro2) and July (from 7.74 +/- 0.74 granules/micro2 to 6.04 +/- 1.13 granules/micro2). In March, however, when T. carnifex chromaffin cells contain both catecholamines, NA (3.88 +/- 0.13 granules/micro2) and A (3.36 +/- 0.05 granules/micro2) in almost equal quantities, NA administration reduced A content (1.29 +/- 1.04 granules/micro2) in the chromaffin cells, enhancing adrenaline secretion (from 681.27 +/- 1.83 pg/ml to 1527.02 +/- 2.11 pg/ml). In July, when the chromaffin cells contain almost exclusively NA granules (NA: 7.42 +/- 0.86 granules/micro2; A: 0.32 +/- 0.13 granules/micro2), NA administration reduced the number of NA granules (5.45 +/- 1.10 granules/micro2), thereby increasing noradrenaline release from the chromaffin cells (from 640.19 +/- 1.65 pg/ml to 1217.0 +/- 1.14 pg/ml). The results of this study indicate that NA influences the steroidogenic cells, eliciting aldosterone release. Noradrenalin effects on the chromaffin cells, increase of NA or A secretion, according to the period of chromaffin cell functional cycle, may be direct and/or mediated through the steroidogenic cells. The existence of intra-adrenal paracrine interactions in T. carnifex is discussed.


Subject(s)
Adrenal Cortex/metabolism , Adrenal Medulla/metabolism , Cell Communication/physiology , Chromaffin Cells/metabolism , Norepinephrine/physiology , Paracrine Communication/physiology , Triturus/physiology , Adrenal Cortex/ultrastructure , Adrenal Medulla/ultrastructure , Aldosterone/blood , Aldosterone/metabolism , Animals , Cell Communication/drug effects , Chromaffin Cells/drug effects , Chromaffin Cells/ultrastructure , Down-Regulation/drug effects , Down-Regulation/physiology , Epinephrine/blood , Epinephrine/metabolism , Lipid Metabolism , Male , Microscopy, Electron , Norepinephrine/pharmacology , Paracrine Communication/drug effects , Seasons , Secretory Vesicles/drug effects , Secretory Vesicles/metabolism , Secretory Vesicles/ultrastructure , Triturus/anatomy & histology
9.
Gen Comp Endocrinol ; 134(3): 229-36, 2003 Dec.
Article in English | MEDLINE | ID: mdl-14636629

ABSTRACT

The occurrence of substance P (SP) immunoreactivity was investigated in the adrenal gland of the lizard Podarcis sicula by ABC immunocytochemical technique: SP-immunoreactivity was present in both adrenaline and noradrenaline cells, in ganglion cells and nerve fibers in the connective capsule surrounding the gland. The involvement of substance P in the modulation of pituitary-interrenal axis was studied in vivo by intraperitoneal injections of SP. The effects were estimated by means of the morphological and morphometrical features of the tissues, as well as the plasma levels of adrenocorticotropic hormone (ACTH), corticosterone and catecholamines, adrenaline and noradrenaline. Substance P (0.07 mg/100 g body wt) decreased ACTH plasma levels and raised corticosterone release from steroidogenic tissue, that showed clear signs of stimulation. In the chromaffin tissue, the decrease in the number of noradrenaline cells, and the increase in the number of adrenaline cells, lowered numeric noradrenaline/adrenaline cell ratio. Moreover, an increase in adrenaline plasma level and a decrease in noradrenaline plasma level were found. The results suggest that (1) also in Reptiles as in other Vertebrates, SP may affect pituitary-adrenal axis activity, and (2) the chromaffin cells may be involved in the paracrine control of steroidogenic activity.


Subject(s)
Adrenal Glands/physiology , Lizards/physiology , Pituitary-Adrenal System/physiology , Substance P/analysis , Adrenal Glands/chemistry , Adrenocorticotropic Hormone/blood , Animals , Catecholamines/blood , Chromaffin Cells/physiology , Corticosterone/blood , Immunohistochemistry , Substance P/pharmacology
10.
Gen Comp Endocrinol ; 131(3): 325-37, 2003 May.
Article in English | MEDLINE | ID: mdl-12714015

ABSTRACT

The aim of this study was to investigate the distribution and function of VIP in the adrenal gland of the lizard, Podarcis sicula. We have shown by immunohistochemistry that VIP fibers were localized exclusively around clusters of chromaffin cells in the dorsal ribbon of the lizard adrenal gland. Moreover, a strong positivity for this peptide was observed within ganglial cells and within most chromaffin cells of the gland. To investigate the effects of VIP on the adrenal gland, we have treated lizards with several doses of this peptide and we have shown that injections of exogenous VIP increased plasma levels of catecholamines and corticosteroids, but not of ACTH. This probably suggests a direct effect of VIP on the control of adrenal hormone secretion without the involvement of the hypothalamo-hypophyseal axis. Our results also establish that the increased levels of the hormones were modulated in a time- and dose-dependent manner. Therefore, our morphological studies showed a clear increased function of steroidogenic cells. In the medullary region, VIP administration induced not only a functional enhancement of adrenaline release from adrenergic cells, but also a shift of noradrenaline cells to adrenaline ones.


Subject(s)
Adrenal Glands/metabolism , Epinephrine/biosynthesis , Lizards/metabolism , Norepinephrine/biosynthesis , Vasoactive Intestinal Peptide/pharmacology , Adrenal Cortex Hormones/blood , Adrenal Glands/anatomy & histology , Adrenal Glands/ultrastructure , Adrenocorticotropic Hormone/blood , Animals , Chromaffin Cells/drug effects , Chromaffin Cells/metabolism , Dose-Response Relationship, Drug , Female , Immunohistochemistry , Male , Microscopy, Electron , Phenylethanolamine N-Methyltransferase/metabolism , Sex Characteristics , Stimulation, Chemical , Time Factors
11.
Eur J Histochem ; 44(3): 285-93, 2000.
Article in English | MEDLINE | ID: mdl-11095100

ABSTRACT

Inhibin is a glycoproteic hormone mostly produced by the gonads. Through a feedback at the pituitary level, it selectively inhibits the release of follicle-stimulating hormone. In mammals, inhibin has been found also in some extragonadal tissues such as placenta, pituitary, adrenal, spleen, kidney, brain and spinal cord. At present, no information is available about the existence of inhibin in reptiles. The aim of the present work is to localise, through immunocytochemical methods, the sites of inhibin production in male lizards during the main phases of the reproductive cycle: the culmination phase (April-June), the early regressive phase (early July), the maximal regressive phase (August) and the winter stasis (January). In the testis, immunostaining is mainly localised in the Leydig cells during the early regressive phase, while it is observed in the Sertoli cells during the maximal regressive phase. In the epididymis, the immunostaining is present only during the reproductive period at the level of secreting cells and inside its ducts. In the adrenal gland, after immunostaining, both chromaffin and steroidogenetic tissues are inhibin-positive during the whole spermatogenetic cycle, though with variable intensity throughout the year: cross-reaction appears more evident from January to April (winter stasis and culmination phase) and weaker in June. However, in captive animals, the reaction persists in chromaffin cells, but disappears in steroidogenetic cells. The functional meaning of the presence of inhibin as a factor in the local regulation of spermatogenesis is discussed.


Subject(s)
Adrenal Glands/cytology , Inhibins/analysis , Lizards/physiology , Testis/cytology , Adrenal Glands/physiology , Animals , Epididymis/cytology , Immunohistochemistry , Male , Reproduction , Seasons , Testis/physiology
12.
Semin Ophthalmol ; 13(4): 199-202, 1998 Dec.
Article in English | MEDLINE | ID: mdl-9878670

ABSTRACT

The optical coherence tomograph is a new, noninvasive technical device that can obtain cross-sectional, high-resolution images-optical coherence tomographs (OCT)-of the retina. This instrument permits an accurate evaluation of various macular and chorioretinal pathologies and the early detection of glaucomatous damage. Images of the retina are obtained similar to ultrasound B-scan, with 10-microm longitudinal resolution. Because the OCT operates with a near-infrared wavelength (about 840 nm), the examination is of minimal discomfort for the patient. OCT examination is indicated in cases of macular pathologies such as vitreoretinal interface syndrome, in the early detection and quantitative assessment of macular edema, and in the evaluation of a glaucomatous damage by measuring the retinal nerve fiber layer thickness. The future role of this instrument and its applications for clinical diagnosis depend on the future improvement and updating of the software.


Subject(s)
Retina/anatomy & histology , Retinal Diseases/diagnosis , Tomography/methods , Humans , Image Processing, Computer-Assisted
13.
Ital J Anat Embryol ; 97(1): 45-53, 1992.
Article in English | MEDLINE | ID: mdl-1288447

ABSTRACT

Because of the similarities of the adrenal glands of mammals and of the lizard Podarcis s. sicula, the latter has already been the subject of various studies on the effects of Propofol and other anaesthetics. Because a relationship between the activities of the thyroid and adrenal glands of this species has been demonstrated, the authors administered Propofol to a species of lizard to investigate its effects on the thyroid gland. Propofol inhibited thyroid activity, promoted steroid synthesis, and caused the contemporaneous appearance of both adrenaline and noradrenaline granules in the cytoplasm of the chromaffin cells. These results suggest that inhibition of the activity of the thyroid gland is secondary to the action of Propofol on the adrenal gland.


Subject(s)
Adrenal Glands/drug effects , Propofol/pharmacology , Thyroid Gland/drug effects , Adrenal Glands/chemistry , Adrenal Glands/ultrastructure , Animals , Cytoplasmic Granules/chemistry , Cytoplasmic Granules/ultrastructure , Lizards , Male , Thyroid Gland/ultrastructure
14.
J Morphol ; 208(1): 83-90, 1991 Apr.
Article in English | MEDLINE | ID: mdl-29865501

ABSTRACT

Morphology of the chromaffin cells of Triturus cristatus during a complete annual cycle has been investigated. General ultrastructural characteristics are similar for all chromaffin cells, including numerous small mitochondria, well-developed Golgi apparatus and rough endoplasmic reticulum with short cisternae. The primary difference among cells is the type of the chromaffin granules they posses. These are of two kinds: adrenalin (A) and noradrenalin granules (NA). Both types are simultaneously present in the chromaffin cells but with different ratios during the year. During December-January and May-August, NA granules largely prevail, while in September-November and February-April, A and NA granules are present in about equal quantities. The total quantity of catecholamine granules, however, is relatively constant throughout the year. These findings suggest that T. cristatus has a single type of chromaffin cell, the granule content of which varies according to different functional states. The catecholamines are apparently discharged by exocytosis.

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