Sex differences in adrenocortical structure and function. XXVI. Further studies on the differences in the compensatory growth of the adrenal cortex of the male and female hamster after unilateral adrenalectomy

The relative adrenal weight of the remaining right adrenal gland was significantly increased 5 days after unilateral adrenalectomy in hamsters of both sexes. This effect was associated with an enlargement of the zonae glomerulosa and fasciculata in males and of the zona fasciculata in females. Unilateral adrenalectomy raised the average volume of zona fasciculata cells in male hamsters and that of zona reticularis cells in females. The number of parenchymal cells in all adrenocortical zones remained unchanged by the removal of the contralateral gland; however, when calculating per mg of adrenal or per cell, the nucleotide uptake by adrenal quarters was notably lowered. A marked drop in plasma cortisol concentration was found in unilaterally adrenalectomized male but not in female hamsters. These findings indicate that the main component of the adrenal compensatory growth in hamsters is the hypertrophy and not the hyperplasia of parenchymal cells.     

Effects of acute administration of ethanol on the rat adrenal cortex

OBJECTIVE: The purpose of this study was to investigate the effect of a single dose of ethanol on rat adrenal cortex and to determine whether the estrous cycle can influence this effect of ethanol. METHOD: Adult female Wistar rats showing proestrus or diestrus Day 1 (n = 12) were treated intraperitoneally with ethanol (4 g/kg body weight). Untreated (n = 15) and saline-injected (n = 14) rats were used as controls. The animals were sacrificed by decapitation 0.5 hour after ethanol administration. Stereological analysis was performed on paraffin sections of adrenal glands stained with AZAN, and the following parameters were determined: absolute volume of the zona glomerulosa, the zona fasciculata and the zona reticularis, numerical density, volume and the mean diameter of adrenocortical cells and of their nuclei, and diameter and length of capillaries. RESULTS: The diameter and volume of adrenocortical cells in the zona fasciculata and the zona reticularis were significantly increased by acute ethanol treatment at proestrus. In the same group of animals, a single dose of ethanol induced significant decrease in numerical density of adrenocortical cells and of their nuclei in all three zones. Increased length of capillaries of the zona fasciculata as well as enhanced level of serum corticosterone was found in ethanol-treated rats at both phases of the estrous cycle, proestrus and diestrus Day 1. CONCLUSIONS: The obtained results indicate that a single dose of ethanol activates adrenal cortex in female rats and that the effect is more pronounced on morphometric parameters at proestrus.     

Target cells for cytochrome p450-catalysed irreversible binding of 7,12-dimethylbenz[a]anthracene (DMBA) in rodent adrenal glands

7,12-Dimethylbenz[a]anthracene (DMBA) is an adrenocorticolytic agent that causes apoplexy (haemorrhage) and massive necrosis in the adrenal cortex in rat. Several explanations regarding the origin of toxicity have been proposed. Huggins and Morii (J Exp Med 114:741-60, 1961) suggested that the cells of the inner adrenal cortex are the primary target, whereas Horváth and Kovács (Pathol Eur 8:43-59, 1973) suggested the vascular endothelium as being the origin of toxicity. In the present study, cultured precision-cut tissue slices were used to localize target cells for irreversible [(3)H]DMBA binding in rat and mouse adrenal cortex. The sites of binding were confirmed by autoradiography in vivo. Irreversible [(3)H]DMBA binding was confined to zona fasciculata/reticularis cells in rat (but not in mouse) adrenal cortex. Pronounced binding was observed in clusters of cells (focal binding), localized predominantly in zona reticularis of rat. [(3)H]DMBA binding in zona fasciculata/reticularis cells was inhibited by the cytochrome p450 1A/B (CYP1A/B) inhibitors ellipticine, alpha-naphthoflavone, and 1-ethynylpyrene. The CYP11B1-inhibitor metyrapone did not reduce [(3)H]DMBA binding. In CYP1-induced (PCB 126-treated) rats and mice, intense irreversible [(3)H]DMBA binding was found also in endothelial cells of the adrenal cortex. The endothelial binding was abolished by the CYP1 inhibitors but remained unaffected by metyrapone. We conclude that the metabolic activation in adrenal parenchymal cells is presumably catalysed by CYP1B1, whereas CYP1A1 presumably catalyses the activation in endothelial cells. We suggest that the adrenocorticolytic effect of DMBA is the result of a dual mode of action, targeting both endothelial and parenchymal cells in the rat adrenal cortex.     

Study of the effects of aging on macromolecular synthesis in mouse steroid secreting cells using microscopic radioautography

The effects of aging on DNA, RNA and protein synthesis in adrenal gland cortical cells and testicular Leydig cells of ddY mice at various ages (from prenatal day 19 to postnatal days 1, 3, 7, 14, months 1 and 6 and 1 and 2 years after birth) were examined using light and electron microscopic (EM) radioautography after labeling with [3H]-thymidine, [3H]-uridine and [3H]-leucine. The percentage of the labeled cells in the adrenal glands after [3H]-thymidine injection was greatest in the zona glomerulosa of the cortex and the medulla on embryonic day 19, in the zona fasciculata and zona reticularis of the cortex on postnatal day 1 and gradually decreased with aging. EM radioautography revealed that well developed cell organelles such as smooth surfaced endoplasmic reticulum, Golgi apparatus, mitochondria with tubular cristae and lipid droplets were more frequently observed in the cytoplasm of unlabeled cells as compared to cells labeled with [3H]-thymidine in the three zones of the cortex. The effects of aging on RNA synthesis in adrenal glands after [3H]-uridine injection revealed that all types of cells of the adrenal gland were labeled. In each cell, silver grains were localized over the nuclei and cytoplasm and were more dense in the nuclei than the cytoplasm. Grain counts were highest in the cortex and medulla on fetal day 19 and then gradually decreased with aging from postnatal day 14 to 1 year after birth. In the cortex, the number of silver grains was higher in the zona glomerulosa than in the other zones from fetal day 19 to 1 year and grain counts were higher in the medulla in the embryonic stage as compared to the postnatal stages. However, the number of labeled mitochondria and the mitochondrial labeling index increased with aging. The [3H]-thymidine labeling index in the Leydig cells of the testis was low at embryonic and early postnatal stages, increased slightly at 6 months and reached a peak at 9 months which was maintained at a relatively high level in senescence. The number of the silver grains over the nuclei and cytoplasm of Leydig cells due to [3H]-uridine labeling was observed from embryonic day 19 and increased from month 3 onwards. From adult to senescence, [3H]-uridine incorporation was maintained at high levels in the nuclei and was relatively low in the cytoplasm. The effects of aging on [3H]-leucine incorporation in Leydig cells were also examined. The labeling indices between embryonic and early postnatal stages showed no obvious differences although the number of the silver grains in both cytoplasm and nucleus increased from 6 months onwards and was maintained at high levels until senescence. From these results, it was concluded that the effects of aging on DNA, RNA and protein synthesis in steroid secreting cells such as adrenal gland cortical cells and testicular Leydig cells of mice correlated with the hormonal changes observed with aging.     

Benznidazole-induced ultrastructural alterations in rat adrenal cortex. Mechanistic studies.

Benznidazole (Bz) (N-benzyl-2-nitro-1-imidazole acetamide) is a drug used against Chagas' disease, a parasitic disease afflicting several millions of Latin Americans. Bz administration to Sprague-Dawley male rats at 100 mg/kg p.o. caused subcellular alterations in the adrenal cortex involving fasciculata and reticularis zones but not in the glomerulosa. There is Bz nitroreductase activity in the adrenal microsomal and mitochondrial fractions but most of it is localized in mitochondria. Activity in the two fractions requires NADPH under anaerobic conditions. Mitochondrial Bz nitroreductase activity was inhibited by oxygen. A minor but statistically significant inhibition was observed in mixtures incubated under carbon monoxide. Microsomal Bz nitroreductase activity was not detected under oxygen atmosphere and was not inhibited under carbon monoxide. No Bz nitroreductase activity mediated by xanthine oxidase or aldehyde oxidase was detected in the cytosolic fraction from rat adrenals. Electron microscopic examination of the adrenal cortex from Bz-treated animals revealed cells with marked lipid accumulation and alterations in nuclei, endoplasmic reticulum and mitochondria in the reticularis and fasciculata zones. In vitro results suggest a Bz nitroreductive activation, with minor or null P-450 participation, leading to reactive metabolites able to cause damage in various organelles.     

Effect of intratracheal and oral application of corticosteroids on the adrenal function test in beagle dogs after ACTH-stimulation.

The effect of synthetic corticosteroids given intratracheally or orally on the adrenal glands of beagle dogs was investigated. The adrenal function was evaluated using a standardized ACTH stimulation test. In addition, histological and morphometrical examinations of the adrenal cortex were performed at the end of the study. Beclomethasone dipropionate given intratracheally at daily dose levels of 0.05, 0.1 and 0.5 mg/kg body weight led to a dose dependent adrenal suppression on the basis of plasma cortisol concentration and eosinophil counts after ACTH stimulation and size of zona fasciculata and reticularis. A complete adrenal suppression was observed at the highest dose level of 0.5 mg/kg body weight. Also the oral administration of 0.1 mg/kg body weight/day of beclomethasone dipropionate had a definite adrenal suppressive effect comparaable to that of 0.1 mg/kg body weight given intratracheally. However, intratracheal administration of fluocortin butylester, a local antiinflammatory drug but systemically a nearly ineffective corticosteroid (2 X 8 mg/kg body weight/day) had no suppressive effect on the adrenal gland of the beagle dog, even after a 320 times higher dose.     

Distribution of [14C]Ethane Dimethanesulfonate in Immature and Adult Male Rats Following an Acute Exposure

Distribution of [¹⁴C]Ethane Dimethanesulfonate in Immature and Adult Male Rats Following an Acute Exposure. Laskey, J. W., Kelce, W. R., Klinefelter, G. R., Gray, L. E., Jr., and Ewing, L. L. (1994). Fundam. Appl. Toxicol. 22, 319-327.In the adult rat, ethane dimethanesulfonate (EDS) reduces testosterone (T) production by killing Leydig cells. Studies have also shown that acute EDS administration produces transient infertility and epididymal effects. Although these later effects were believed to be indirect results of the reduced Leydig cell T production, it was recently found that the epididymal effects were partially a direct result of in vivo EDS treatment. In contrast to the Leydig cells of the adult rat, immature Leydig cells are affected by EDS only at doses four- to sixfold higher than those that affect mature Leydig cells. In fact, the Leydig cells of the adult rat seem to be uniquely susceptible to the cytotoxic effects of EDS. Steroidogenesis in other organs, like the adrenal and ovary, are unaffected in vivo at doses that eliminate T production in males. In addition, studies have shown that doses of EDS that kill Leydig cells in vitro , isolated from the testes of adult rats, have no effect on similarly exposed hepatocytes. Hence, it was the objective of this study to describe the distribution and temporal fate of EDS in target (testes and epididymides) and nontarget tissues in immature and adult male rats and to determine if this information would explain either the age- or tissue-related susceptibility to EDS. We have concluded from this study that tissue distribution, integrated in vivo EDS dose, and differences in EDS metabolism are not the only factors contributing to the difference in sensitivity. The information collected in this study will enable us to use in vitro EDS concentrations for examination of the mechanism of action at doses relevant to those produced in vivo.     

Adrenocortical toxicity of 3-methylsulphonyl-DDE; 3: Studies in fetal and suckling mice.

Irreversible binding and toxicity of the DDT metabolite 3-methylsulphonyl-DDE (MeSO2-DDE) were examined in fetuses and suckling pups following administration to pregnant or lactating C57Bl mice. Tape-section autoradiography showed a high and tissue-specific accumulation and binding of MeSO2-DDE-14C-derived radioactivity in the late gestational fetal adrenal cortex. According to microautoradiography an irreversibly bound residue was confined to the zona fasciculata. Similarly, there was a high concentration of irreversibly bound 14C-labelled material in the adrenal zona fasciculata of suckling pups. Intraperitoneal injection of MeSO2-DDE-14C to lactating mice resulted in higher concentrations of radioactivity in the liver and stomach contents (milk) of the suckling pups than in the maternal liver. This treatment also resulted in a higher level of radioactivity in the adrenals of the pups than in the maternal adrenals, both at a subtoxic and at a toxic dose. Histopathologic examination of adrenals from suckling pups revealed extensive vacuolation and necrosis of the zona fasciculata 2 days following a single dose of MeSO2-DDE (25 mg/kg) to the dam. In the fetal adrenal zona fasciculata, slight degenerative changes were observed following a maternal dose of 50 mg/kg. In conclusion, the study shows that MeSO2-DDE is a highly tissue-specific toxicant to the fetal and postnatal adrenal zona fasciculata in mice. Based on the present data and on previous results in adult mice, we propose that a tissue-specific activation to a reactive metabolite in the fetal and postnatal adrenal cortex is mediated by cytochrome P-450 (11 beta).     

燃煤型氟中毒大鼠血清睾酮水平的变化及机制的初步研究

目的:研究燃煤型氟中毒大鼠血清睾酮的变化及可能的机制.方法:以SD大鼠为研究对象,按体质量均衡随机分为对照组、低氟组、中氟组、高氟组4组.各染毒组喂饲含不同比例的燃煤型氟中毒病区煤烘玉米的饲料,复制燃煤型氟中毒动物模型.180d以股动脉放血法处死动物.查看氟斑牙,测尿氟、血清睾酮水平,常规制成肾上腺和睾丸HE染色病理切...     

Dose-dependent actions of spironolactone on the inner and outer zones of the guinea pig adrenal cortex.

The results of prior in vitro studies indicated that spironolactone (SL) caused far greater degradation of cytochromes P-450 in the outer (zona glomerulosa plus zona fasciculata) than inner (zona reticularis) zone of the guinea pig adrenal cortex and selectively decreased microsomal 17 alpha-hydroxylase activity. Studies were done to determine if the effects of SL in vivo were similarly zone and/or enzyme selective. Administration of high doses of SL (100 mg/kg) to guinea pigs altered the gross appearance of the adrenal glands and caused declines in 17 alpha- and 21-hydroxylase activities in both inner and outer zone microsomal preparations. The losses in enzyme activities were accompanied by decreases in microsomal cytochrome P-450, cytochrome b5 and heme concentrations, and in mitochondrial P-450 levels in both zones. Microsomal P-450(17 alpha) apoprotein levels were also decreased in both zones. A lower dose (25 mg/kg) of SL did not affect adrenal morphology, but decreased microsomal P-450 levels in both zones. Neither mitochondrial P-450 nor microsomal b5 concentrations were affected in either zone. 17 alpha-Hydroxylase activities and P-450(17 alpha) apoprotein concentrations in both zones were decreased by the lower dose of SL, but 21-hydroxylase activity declined in the inner zone only. The results indicate that very high doses of SL have a variety of nonspecific effects on the adrenals which may be the consequence of drug toxicity. Nontoxic doses exert more selective effects on microsomal cytochromes P-450 in both adrenal zones, more closely mimicking the in vitro actions of the drug.     

Mitochondrial alterations in aged rat adrenal cortical cells

Mitochondrial alteration in aged rat adrenal cortical cells were studied. Severe mitochondrial alterations were predominantly observed in the zonae fasciculata and reticularis of the adrenal cortex. Many adrenal cortical mitochondria from these zones were relatively larger in size and more irregular in shape. The matrix of altered mitochondria appeared denser than normal and the intramitochondrial cristae including myelin-like membrane configurations and parallel arrays were seen. Intramitochondrial inclusions such as paracrystalloid structures were also noted. In addition, giant mitochondria with various inclusions such as highly electron dense lipid-like materials, large vacuoles and other cytoplasmic organelles including small mitochondria were characteristically observed. Based on these data, functional aspects of the altered mitochondria in aged rat adrenal cortical cells were discussed.     

ENDOTHELIN RECEPTORS IN RAT ADRENAL GLAND VISUALIZED BY QUANTITATIVE AUTORADIOGRAPHY

1. The radioligand [125I]-endothelin was used to map receptors for endothelin in rat adrenal gland using in vitro autoradiography and computerized densitometry. 2. In the adrenal, a high density of binding was found in the adrenal medulla (binding affinity constant 0.18 +/- 0.11 X 10(9)M-1) and zona glomerulosa (binding affinity constant 0.18 +/- 0.07 X 10(9)M-1). Binding was low to undetectable in the zona fasciculata and zona reticularis. Unrelated peptides did not displace endothelin. 3. These results provide evidence of endothelin receptor distribution in adrenal gland and suggest that endothelin might exert multiple actions in the adrenal gland on catecholamine and aldosterone biosynthesis and secretion.     

Compensatory adrenal growth in dexamethasone treated male and female hamsters

The aim of the study was to investigate the unilateral adrenalectomy - induced compensatory adrenal growth in dexamethasone treated male and female hamsters (Mesocricetus auratus Waterhouse). Animals were treated for 5 days with 25 micrograms dexamethasone/animal/day or with 0.2 ml 0.9% NaCl. The first injection was made 0.5-1 h after monolateral adrenalectomy or sham operation. In three sets of experiments male and female hamsters received no injection. Only in one of three experiments was the relative adrenal weight of monoadrenalectomised male and female hamsters receiving no injections higher than in sham operated groups. In the case of NaCl treatment, only in one group of monoadrenalectomised males was the relative weight of the right adrenal higher than in the control group. On the contrary, in all three experiments with dexamethasone treatment the relative weight of the solitary adrenal was higher than in sham operated animals, while there was no difference among appropriate groups of females. In monoadrenalectomised dexamethasone-treated male hamsters, volume of the glomerulosa and reticularis zones was higher than in sham operated group. Neither the average cell volume in particular adrenocortical zones nor the number of parenchymal cells in the zones and in the entire cortex were changed due to adrenalectomy in dexamethasone treated males. There was no difference in all stereologic parameters studied when monoadrenalectomised and sham operated dexamethasone treated females were compared. Plasma cortisol level was lower in hemiadrenalectomised dexamethasone-administered males, while 3H-thymidine incorporation was higher in both male and female dexamethasone-treated hemiadrenalectomised hamsters. The obtained results demonstrate the evident sex-dependent response of the hamster adrenal gland to monoadrenalectomy and dexamethasone.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of fluocortin butylester and beclomethasone dipropionate on the adrenal gland in beagle dogs.

The effect of butyl-6 alpha-fluoro-11 beta-hydroxy-16 alpha-methyl-3,20-dioxo-1,4-pregnadien-21-oate (fluocortin butylester, Vaspit) administered intratracheally and of beclomethasone dipropionate given intratracheally or orally on the adrenal glands of beagle dogs was investigated. The adrenal function was evaluated using a standardized ACTH stimulation test including eosinophil counts 5 h after a single i.v. injection of 0.02mg (approximately 2 IU) ACTH/kg body weight were found as well as the histological and morphometrical examination of the adrenal cortex. The cortisol determination (with Clark's method) 1.5 h and eosinophil counts to be the optimum indices for the evaluation of adrenal function. Beclomethasone dipropionate given intratracheally at daily dose levels of 0.05; 0.1 and 0.5 mg/kg body weight lead to a dose dependent adrenal suppression on the basis of plasma cortisol concentration, eosinophil counts after ACTH stimulation and size of zona fasciculata and reticularis. A complete adrenal suppression was observed at the highest dose level of 0.5 mg/kg bw. Also the oral administration of 0.1 mg/kg bw./day of beclomethasone dipropionate had a definite adrenal suppressive effect comparable to that of 0.1 mg/kg bw. given intratracheally. However, intratracheal administration of fluocortin butylester even after a 320 times higher dose (2 X 8 mg/kg bw./day) had no suppressive effect on the adrenal gland of the beagle dog.     

The effect of isomers of DDD on the ACTH-induced steroid output, histology and ultrastructure of the dog adrenal cortex

The effect of 3 geometric isomers of DDD on ACTH-induced steroid production, histology, and ultrastructure of the dog adrenal cortex were examined. When administered iv, equal doses of all 3 compounds eventually inhibited ACTH-induced steroid production. The order of onset of inhibition was m,p′-DDD > o,p′-DDD > p,p′-DDD with the inhibition reaching 50% of control values at 27 min, 87 min and between 4–18 hr, respectively. Histologic examination of the various zones of the adrenal cortex showed minimal effects, from any of the isomers, on the zona glomerulosa at times when the internal structure and spacial arrangement of the cells of the zona fasciculata and reticularis were markedly disrupted. Electron micrographs revealed that these DDD isomers exhibited very minimal effects on the mitochondria of the zona glomerulosa. On the other hand, the mitochondria of the zonas fasciculata-reticularis underwent progressive swelling, dissolution, and eventual rupture following DDD treatment. The order of onset of histologic and ultrastructural effects was m,p′-DDD > o,p′-DDD > p,p′-DDD. However, for each isomer the ultrastructural damage was detected prior to the observation of histologic lesions. Thus, there was a marked temporal correlation between the percentage inhibition of ACTH-induced steroid production, the disruption of normal cellular structure and arrangement in the innermost zones of the adrenal cortex, and the severity of the DDD-induced mitochondria damage in the cells of the zonas fasciculata-reticularis by each of the 3 isomers of DDD.     

Distribution of [14C] Ethane Dimethanesulfonate in Immature and Adult Male Rats Following an Acute Exposure

In the adult rat, ethane dimethanesulfonate (EDS) reduces testosterone(T) production by killing Leydig cells. Studies have also shownthat acute EDS administration produces transient infertilityand epididymal effects. Although these later effects were believedto be indirect results of the reduced Leydig cell T production,it was recently found that the epididymal effects were partiallya direct result of in vivo EDS treatment. In contrast to theLeydig cells of the adult rat, immature Leydig cells are affectedby EDS only at doses four- to sixfold higher than those thataffect mature Leydig cells. In fact, the Leydig cells of theadult rat seem to be uniquely susceptible to the cytotoxic effectsof EDS. Steroidogenesis in other organs, like the adrenal andovary, are unaffected in vivo at doses that eliminate T productionin males. In addition, studies have shown that doses of EDSthat kill Leydig cells in vitro, isolated from the testes ofadult rats, have no effect on similarly exposed hepatocytes.Hence, it was the objective of this study to describe the distributionand temporal fate of EDS in target (testes and epididy mides)and nontarget tissues in immature and adult male rats and todetermine if this information would explain either the age-or tissue-related susceptibility to EDS. We have concluded fromthis study that tissue distribution, integrated in vivo EDSdose, and differences in EDS metabolism are not the only factors contributing to the difference in sensitivity. The information collected in this study will enable us to use in vitroEDS concentrations for examination of the mechanism of actionat doses relevant to those produced in vivo.     

Histopathological effects of Naja haje snake venom and a venom gland extract of the scorpion Buthus quinquestriatus on the liver,suprarenal gland and pancreas of mice

Lethal doses of Naja haje snake venom produced central and midzonal hydropic degeneration in hepatic lobules. Buthus quinquestriatus scorpion venom gland extract caused peripheral zonal hydropic degeneration, sinusoidal dilatation and disruption. Fatty degenerative changes started earlier after use of the scorpion preparation. Both preparations depleted glycogen, inhibited succinic dehydrogenase and increased alkaline phosphatase activity in degenerated hepatocytes. Signs of regeneration followed sublethal doses of Naja haje venom. Lethal doses of both venom preparations caused rupture of the capsule of the suprarenal gland and detachment of its cortex. Blood extravasated in the medulla. Zona fasciculata cells were hypertrophied and vacuolated and cortical lipids increased. Depletion of ascorbic acid and medullary catecholamines occurred. After a single sublethal dose the zona reticularis region increased in thickness due to proliferation of its cells. These cells invaded the medullary clumps. Repeated sublethal doses increased the thickness of both the zona fasciculata and reticularis. In the pancreas, lethal doses of both venom preparations produced vacuolization of alpha and beta cells. Partial and complete degranulation were observed in hydropically degenerated beta cells. Alpha cells showed decreased alkaline phosphatase activity.     

Immature rat Leydig cells are intrinsically less sensitive than adult Leydig cells to ethane dimethanesulfonate.

Leydig cells from immature rat testes appear to be insensitive to doses of ethane-1,2-dimethanesulfonate (EDS) which eliminate Leydig cells from adult rat testes. We sought to determine whether this differential response to EDS is intrinsic to the Leydig cell or mediated by other intra- or extratesticular differences between adult and immature rats. To differentiate among these possibilities, Leydig cells were exposed to EDS (1) in vivo, (2) through in vitro testicular perfusion, or (3) in highly purified Leydig cell primary cultures. Four days after ip injections of 85 mg EDS/kg body wt Leydig cells were eliminated from testes of adult, but not immature rats. Total androgen production by testes perfused in vitro with 94 micrograms EDS/ml was dramatically reduced in adult, but not immature rats. Highly purified adult, but not immature, rat Leydig cells were far more sensitive to the effects of EDS on luteinizing hormone-stimulated androgen production (functional effects; apparent EC50 = 94 for adult and 407 micrograms/ml for immature rat Leydig cells) and on [35S]methionine incorporation (cytotoxic effects; apparent EC50 = 140 for adult and 1000 micrograms/ml for immature rat Leydig cells). Finally, the in vitro effects of EDS were both cell type and chemical specific. Since the differential response of adult and immature rat Leydig cells to EDS was manifest in vivo, during in vitro testicular perfusion, and in highly purified Leydig cell primary cultures, we conclude that immature rat Leydig cells are intrinsically less sensitive to the specific cytotoxic effects of EDS than adult rat Leydig cells.     

Distribution and coregulation of three peptide receptors in adrenals

Receptors sites for angiotensin II and atrial natriuretic factor were concentrated in the zone glomerulosa of the adrenal cortex in the rat, mouse, hamster, rhesus monkey, guinea-pig and the cow. Angiotensin Ii receptor sites were also accumulated in adrenal medullary tissue of the rat, mouse and the hamster. With exception of the cow the zonae fasciculata and reticulata of the adrenal cortex were not labelled with the angiotensin II ligand, but showed a moderate density of atrial natriuretic factor receptor sites in all species except the rhesus monkey. In comparison, somatostatin receptors were even more heterogeneously distributed in all species mentioned above. In the rat, the increased growth of zona glomerulosa cells found after three weeks of sodium deprivation was accompanied by a similar increase in number of receptor sites for angiotensin II, atrial natriuretic factor and somatostatin. This shows that all three peptide receptors are regulated simultaneously by a single metabolic disturbance, suggesting that they might be localized on the same cell type in the adrenal cortex.     

Ethanol and nitric oxide modulate expression of glucocorticoid receptor in the rat adrenal cortex

BackgroundThis study was performed to investigate expression and distribution of glucocorticoid receptor (GR) in the rat adrenal cortex, acute effect of ethanol on its expression and possible role of endogenous nitric oxide (NO) in this phenomenon.MethodsAdult female Wistar rats showing diestrus day 1 were treated with: a) ethanol (2 or 4 g/kg body weight (b.w.), ip), b) N^ω-nitro-L-argmine methyl ester (L-NAME), well-known competitive inhibitor of all isoforms of NO synthase (NOS), (30 mg/kg b.w., sc) followed by ethanol (4 g/kg, ip) 3 h later and c) L-NAME (30 mg/kg b.w., sc) followed by saline (ip) 3 h later. Untreated rats were used as controls. Adrenocortical expression of GR was estimated by immunohistochemistry.ResultsStrong nuclear GR staining was observed throughout the cortex of control rats. Acute ethanol treatment significantly decreased the expression of GR in the zona fasciculata and zona reticularis. Blockade of NO formation had no influence on this effect of ethanol, whereas L-NAME itself induced significant decline in GR immunoreactivity.ConclusionsObtained findings are the first to demonstrate localization and distribution of the GR throughout the rat adrenal cortex and to suggest that ethanol as well as endogenous NO may modulate adrenocortical expression of this steroid receptor.