Chronic stress and its effects on adrenal cortex apoptosis in pregnant rats

The model of chronic intermittent stress by immobilization during pregnancy may produce alterations in the mechanisms that maintain adrenal gland homeostasis. In earlier investigations using this model, significant variations in plasma prolactin and corticosterone levels, and adrenal gland weights were observed. We hypothesized that chronic stress causes changes in apoptosis in the adrenal glands of pregnant rats. We identified and quantified apoptotic cells in the adrenal cortex and examined their ultrastructural characteristics using transmission electron microscopy. Adrenal glands of pregnant rats at gestation days 12, 17 and 21 were studied for control and experimental (stressed) rats. Immunolabelling techniques, stereological analysis and image quantification of adrenal gland sections were combined to determine differences in apoptosis in the different cell populations of the adrenal cortex. The apoptotic index of the experimental rats showed a significant reduction at gestation day 17, while at days 12 and 21 there were no differences from controls. Moreover, the apoptotic index of the reticular zones in control and experimental animals showed a significant increase compared to the glomerular and fascicular zones at the three gestation times studied. Chronic stress by immobilization reduced the caspase-dependent apoptotic index at gestation day 17, which may be related to variations in plasma concentrations of estrogens and prolactin.     

Effects of Electroconvulsive Shock on Tetrahydrobiopterin and GTP-Cyclohydrolase Activity in the Brain and Adrenal Gland of the Rat

The effects of a single and repeated electroconvulsive shock (ECS) (300 mA, 0.2 s) on tetrahydrobiopterin (BH4) levels and GTP-cyclohydrolase activity in the brain and adrenal glands of rats were examined. Twenty-four hours after the last ECS treatment (one/day for 7 days), biopterin levels were significantly elevated in the locus coeruleus, hippocampus, frontal cortex, hypothalamus, ventral tegmental area, and adrenal gland. There were no changes in biopterin levels after a single application of ECS. GTP-cyclohydrolase activity was significantly increased in the locus coeruleus, frontal cortex, hippocampus, hypothalamus, and adrenal gland 24 h after repeated ECS and remained elevated in certain tissues up to 8 days after the last treatment. Kinetic analysis of adrenal and locus coeruleus GTP-cyclohydrolase 1 day after 7 days of ECS showed significant changes in both Km and Vmax values. These data suggest that the long-term increases in BH4 levels and GTP-cyclohydrolase activity after repeated ECS may play a part in the mediation of the antidepressant effects of ECS.     

Rat Hippocampal Lactate Efflux During Electroconvulsive Shock or Stress Is Differently Dependent on Entorhinal Cortex and Adrenal Integrity

The role of the entorhinal cortex and the adrenal gland in rat hippocampal lactate formation was assessed during and after a short-lasting immobilization stress and electroconvulsive shock (ECS). Extracellular lactate was measured on-line using microdialysis and enzyme reactions (a technique named lactography); in some rats, unilateral lesions of the entorhinal cortex were made or the bilateral adrenal glands were removed. The stress-evoked increase in hippocampus lactate was not altered either ipsi- or contralateral to an entorhinal cortex lesion. The response to ECS was attenuated only in the hippocampus ipsilateral to the entorhinal cortex lesion. Removal of bilateral adrenal glands caused some delay in the increase in hippocampal lactate after ECS and a major reduction in the stress-evoked lactate response. These results indicate that (1) the entorhinal cortex is activated by ECS, thereby activating hippocampal lactate efflux and presumably metabolism, and (2) the adrenal gland is essential in the response to stress and, to a minor extent, in the ECS-altered hippocampal metabolism.     

Chronic stress and high sucrose intake cause distinctive morphometric effects in the adrenal glands of post-weaned rats

We investigated the effects of chronic stress combined with high sucrose intake on the morphology of the adrenal glands in young rats. Male Wistar rats were fed a standard chow diet and allocated into control (C; tap water), chronic restraint stress (St), 30% sucrose diet (S30) and 30% sucrose diet + chronic restraint stress (S30 + St) groups. St consisted of 1 h daily sessions, 5 days/week for 4 weeks. Chronic stress reduced the thickness of the zona glomerulosa (ZG) and zona fasciculata (ZF) in both right and left glands; the thickness of the zona reticularis (ZR) was increased in the right gland. Cell density was greater in the ZF and medulla of both right and left glands, whereas cell density increased in the ZR of only the left gland. The percentage of small cells was lower in the ZG, whereas more large cells were found in the left gland. A similar result was obtained for the ZF, ZR and medulla in both right and left glands. Chronic stress increased the area covered by blood vessels in the ZR of the right gland, but decreased the area in the ZR of the left gland. The area covered by blood vessels was reduced in the medulla of both right and left glands in rats subjected to chronic stress. Infiltration of immune cells was increased by chronic stress in all layers of the cortex of the left gland, but was reduced in the medulla of the right gland. A high sucrose diet reduced the thickness of the medulla in the left gland. Cell proliferation increased in the ZG of the right gland and the weight of the right adrenal gland increased. Reduced cell proliferation in the ZG of the left gland was associated with a reduction in the area covered by blood vessels. In addition, the area covered by blood vessels decreased in the medulla of both glands. Our findings demonstrate that exposure to chronic stress during early life causes morphometric changes in adrenal glands.     

Hypertrophy and altered activity of the adrenal cortex in Homer 1 knockout mice

Homer 1 gene products are involved in synaptic transmission and plasticity, and hence, distinct behavioral abnormalities, including anxiety- and depression-like behaviors, have been observed in Homer 1 knockout (KO) mice. Here we report that Homer 1 KO mice additionally exhibit a pronounced endocrine phenotype, displaying a profoundly increased adrenal gland weight and increased adrenal/body weight ratio. Histological examinations of Homer 1 deficient adrenal glands revealed an increased size of the adrenal cortex, especially the sizes of the zona fasciculata and zona glomerulosa. Moreover, the plasma corticosterone and aldosterone were higher in Homer 1 KO than wild-type (WT) mice while the plasma ACTH levels were not different between the genotypes. The in vivo ACTH test revealed that corticosterone and aldosterone plasma levels were higher in saline injected Homer 1 KO mice than in WT mice (saline injected mice served as controls for the respective groups of ACTH-injected animals), but the magnitude of steroid responses to ACTH was similar in both genotypes. In contrast, an in vitro experiment performed on isolated cells of adrenal cortex clearly showed increased production of both steroids in response to ACTH in Homer 1 KO cells, which is in line with an ~8-fold increase in the expression of ACTH receptor mRNA in the adrenal cortex of these mutants. These results, together with the detection of Homer 1 mRNA and protein in the adrenal cortex of WT mice, indicate that Homer 1 directly affects the steroidogenic function of the adrenal glands.     

Distribution and colocalization of nitric oxide synthase and NADPH-diaphorase in adrenal gland of developing,adult and aging Sprague-Dawley rats

The distribution and colocalization of nitric oxide synthase and nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-diaphorase) was investigated in the adrenal gland of developing, adult and aging rats with the use of immunohistochemical and histochemical techniques. Nitric oxide synthase-immunoreactive neurons within the adrenal gland were found from the 20th day of gestation onwards. During early development the neurons were found as small clusters of smaller-size cells compared to those observed in the adult gland. Their number reached that of adult level by the 4th day after birth, and in the glands from aging rats a 28.6% increase was observed. Whilst no immunofluorescence was seen in chromaffin cells during early development, some cells from glands of aging rats showed nitric oxide synthase-immunoreactivity with varying intensity. The immunoreactive neurons from postnatal rat adrenals were also positive for NADPH-diaphorase, whilst those in prenatal rats were negative or lightly stained. Nitric oxide synthase-immunoreactive nerve fibres were present in all adrenal glands examined from the 16th day of gestation onwards. A considerable degree of variation in the distribution of immunoreactive fibres both in medulla and outer region of cortex at the different age groups was observed and described. Most, but not all, nitric oxide synthase-immunoreactive nerve fibres also showed NADPH-diaphorase staining.     

Nestin expression in normal adrenal gland and adrenocortical tumors

Human adrenocortical cells have been shown to express cytokeratins and vimentin. Nestin is an intermediate filament protein that is mainly expressed in the developing nervous system and that has been recently reported in rat adrenal gland as well. Using immunohistochemical and biochemical approaches, the present study demonstrates that nestin is constantly expressed in situ in the cortex of normal human adrenal glands. Nestin expressing cells were prevalently located in the zona reticularis but some positive cells could be spotted in the zona fasciculata as well. Moreover, patches of nestin-positive cells have been constantly detected on sections of cortical adenomas. In contrast, adrenal carcinomas displayed a variable number of nestin-immunoreactive cells that in some cases were virtually absent. Samples of renal clear cell carcinoma metastasis in the adrenals were also examined which did not show nestin-immunoreactivity. We propose that a positive nestin-immunoreaction could be useful in differential diagnosis of clear cell tumors in adrenal glands.     

Morphology and ultrastructure of the adrenal gland in Bactrian camels (Camelus bactrianus)

In the present study, we examined the morphological features of the adrenal gland in Bactrian camel by means of digital anatomy, light and electron microscopy. Our findings testified that the gland was divided into three parts, capsule, cortex and medulla from outside to inside as other mammals, and the cortex itself was further distinguished into four zones: zona glomerulosa, zona intermedia, zona fasciculate and zona reticularis. Notably, the zona intermedia could be seen clearly in the glands from females and castrated males, whereas it was not morphologically clear in male. There was a great deal of lipid droplets in the zona fasciculate, while it was fewer in the zona glomerulosa and zona reticularis. The cytoplasm of adrenocortical cell contained rich mitochondria and endoplasmic reticulum. The adrenal medulla was well-developed with two separations of external and internal zones. The most obvious histological property of adrenal medulla cells were that they contained a huge number of electron-dense granules enveloped by the membrane, and so medulla cells could be divided into norepinephrine cells and epinephrine cells. Moreover, the cortical cuffs were frequently present in adrenal gland. Results of this study provides a theoretical basis necessary for ongoing investigations on Bactrian camels and their good adaptability in arid and semi-arid circumstances.     

Adaptation of the bank vole (Clethrionomys glareolus Schreber) to conditions of biogeochemical province with abnormally high content of nickel, cobalt and chromium

Morphophysiological characteristics and peculiarities of adrenal gland of bank vole (Clethrionomys glareolus) were studied in the area of natural biogeochemical province with abnormally high content of nickel, cobalt and chromium. The control population inhabited area with usual content of these elements. We used 4-factor analysis of variance to estimate the influence of geochemical conditions, phase of population cycle, sex and reproductive state on the morphophysiological characteristics of animals and functional activity of adrenal gland. Animals from area with high concentration of Ni, Co and Cr show an increase in relative mass of adrenal glands, fascicular zone of adrenal cortex, size of cells and their nuclei. All these changes can be considered as an evidence of increased secretion of glucocorticoids. It is shown that phase of population cycle influences fatness of animals, size of nuclei, cells and adrenal cortex. Females in comparison with males are characterized with higher indexes of liver and adrenal gland, as well as morphometric indexes of adrenal cortex. The maturation of animals is accompanied with increase in body mass, fatness and relative mass of adrenal glands, the size of cortex zone, nuclei and cells themselves. It is supposed that the effect of "geochemical factor" results in intensification of glucocorticoid secretion of adrenal costex, thus increasing non-specific resistance of animals inhabiting area with high concentration of heavy metals. Such factors as "phase of population cycle", "sex" and "reproductive state", influence mineralocorticoid activity, glucocorticoid and androgenic functions of adrenal cortex. Some factors show synergetic effect.     

Role of the adrenal glands in the cytostatic action mechanism of antitumor antibiotics

The state of the steroidogenic function of the adrenal glands, lipid spectrum of the adrenal gland tissue and metabolism rate of 11-oxycorticosteroids (11-OCS) in the liver tissue and their levels in the blood plasma were studied on rats after a single administration of karminomycin in a dose of LD50 (1.55 mg/kg). The hormones of the adrenal cortex were shown to play a definite role in the mechanism of the karminomycin damaging effect. Dependence of the changes on the time of the drug effect was noted. The shifts were of a reversible character. No direct toxic damages in the tissue of the adrenal glands were observed. Only an increase in the 11-OCS blood levels and a decrease in the steroid metabolism in the liver tissue were shown. The latter must be due to the direct cytotoxic effect of karminomycin on the tissue of this organ.     

白暨豚肾上腺的研究

白鱀豚肾上腺重与体重的平均比值为0.25克/公斤,皮质体积与髓质体积的比值为6.59。白鱀豚肾上腺的组织结构与其它海豚相似,它有比较发达的球状带。讨论了白鱀豚肾上腺形态变化在年龄生长、授乳等生理过程和在自然环境、豢养环境生态适应上的意义。并报道了一例罕见的白鱀豚肾上腺先天性表皮样囊肿。       

Morphometric and histological studies on the adrenal glands of the camel Camelus dromedarius

The adrenal gland of the camel consists of an outer cortex and an inner medulla. The general disposition of the cortex and medulla, however, differs occasionally from that of other mammals. Extensions of medulla could reach as far as the periphery of the cortex. Islet of medullary tissue may be found in sections of the cortex and cortical tissue consisting of all zones of the cortex may occur around arteries or nerves in the medulla. The medulla may be separated from the cortex by connective tissue especially in old camels. The arrangement of noradrenaline-secreting cells is different from that in other ruminants; they are found in groups scattered between the adrenaline-secreting cells. Bundles of smooth muscle occur in venules at the corticomedullary interface. Accessory adrenal glands are found embedded in the renal fat. They are similar in structure to the adrenal gland. The adrenal cortex forms 74% of the volume of the gland and the ratio of the cortex to medulla is 4:1. The zona glomerulosa, fasciculata and reticularis constitute about 13%, 53%, and 29% by volume of the cortex, respectively.     

Connexin 43 ontogeny in fetal sheep adrenal glands

We examined fetal sheep adrenal glands from 99 to 130 days of gestational age (dGA) to see how connexin 43 (Cx43), the major if not the only adult adrenal gap junction protein, changes expression as the adrenal cortex emerges from the well-documented refractory period to participate in labor and delivery. Immunocytochemical technique and Western blot were used to examine changes in the quantity and quality of Cx43. In addition, adrenal glands of ACTH infused fetuses or of fetuses from dexamethasone injected ewes underwent image analysis quantification after Cx43 immunostaining. Finally, fetal adrenal glands, from fetuses splanchnic nerve sectioned (SPLX) at 125 dGA, were examined for the pattern of Cx43 immunostaining at 131 days of gestation. From 100 to 130 dGA, the amount of Cx43 in cells of the adrenal cortex increased steadily while the pattern of immunoreactivity changed from predominantly cytoplasmic to membrane bound. At 100-103 dGA, ACTH infusion increased the size of the cortex, but decreased the expression of Cx43 per unit area while dexamethasone had no effect on either parameter. Lastly, the expression of Cx43 as a membrane bound protein was not delayed or reversed by SPLX. We conclude that the described changes in Cx43 are most intriguing given their temporal relationship to the described preparturient increases in ACTH and cortisol in peripheral fetal plasma as term approaches and deserve further investigation.     

Detection of the pro-opiomelanocortin peptide fragments--beta-endorphin and ACTH--in the adrenals of rats and mice by immunohistochemistry

Independent peptide fragments of pro-opiomelanocortin molecule, beta-endorphin and ACTH, have been detected immunohistochemically in the adrenal glands of rats and mice. Immunoreactive beta-endorphin and ACTH have been revealed in the adrenal medulla and reticular zone of the adrenal cortex. beta-endorphin and ACTH distribution patterns in adrenal sections were identical, which is indicative of the linked synthesis of these peptides in the adrenal gland. The data obtained suggest the existence of pituitary-independent mechanisms regulating corticosteroidogenesis in the adrenal gland, involving adrenal pro-opiomelanocortin fragments.     

TREATMENT OF ASTHMA: Somatic and Psychiatric

Various conditions of the adrenal gland are amenable to surgical treatment. Removal of a pheochromocytoma is almost always indicated when the tumor is diagnosed. The results of extirpation have been excellent in cases in which patients were operated upon before the onset of chronic hypertension. Removal of the “nerve cell” tumors of the adrenal is indicated if metastasis cannot be demonstrated.Hypofunction of the adrenal cortex may be partially alleviated by the repeated implantation of pellets of desoxycorticosterone acetate. Hyperfunction of the adrenal cortex causes a variety of clinical manifestations depending upon which of the numerous hormones are affected. Removal of a cortical tumor alleviates these symptoms. These tumors are malignant in more than 50 per cent of cases, and recurrence is frequent. Bilateral hyperplasia of the glands rather than a tumor may be present. In such circumstances, resection of 95 per cent of the adrenal tissue is effective in controlling the symptoms of the disease.Total bilateral excision of the adrenals is, at present, under investigation as a means of treatment for a variety of conditions.     

Development of the hormonal reaction to stress in the ontogenesis of the baboon Papio hamadryas

The hormonal reaction of adrenal and gonadal glands of baboons at various ages was studied under 2 hr immobilization stress condition. Concentrations of cortisol, 11-deoxycortisol, 17-hydroxypregnenolone, dehydroepiandrosterone and testosterone were determined by radioimmunoassay in the monkey blood plasma at different times during the stress reaction. A more pronounced reaction of adrenal cortex was shown in 1 year old baboons. The peak of cortisol level in immature monkeys under stress conditions was registered much earlier than in adult monkeys.     

Operations on the adrenal glands

Various conditions of the adrenal gland are amenable to surgical treatment. Removal of a pheochromocytoma is almost always indicated when the tumor is diagnosed. The results of extirpation have been excellent in cases in which patients were operated upon before the onset of chronic hypertension. Removal of the "nerve cell" tumors of the adrenal is indicated if metastasis cannot be demonstrated. Hypofunction of the adrenal cortex may be partially alleviated by the repeated implantation of pellets of desoxycorticosterone acetate. Hyperfunction of the adrenal cortex causes a variety of clinical manifestations depending upon which of the numerous hormones are affected. Removal of a cortical tumor alleviates these symptoms. These tumors are malignant in more than 50 per cent of cases, and recurrence is frequent. Bilateral hyperplasia of the glands rather than a tumor may be present. In such circumstances, resection of 95 per cent of the adrenal tissue is effective in controlling the symptoms of the disease. Total bilateral excision of the adrenals is, at present, under investigation as a means of treatment for a variety of conditions.     

Adrenal glucocorticoid function and cytoplasmic dehydrogenase activity in the presnece of mechanical and toxic liver damage]

Against the background of low steroid metabolism in the liver there was noted some decrease in the rate of corticosterone synthesis by the adrenal gland sections, and also, a decrease in the dehydrogenase activity in the cytoplasm of adrenal cells in male rats 48 hours after partial hepatectomy, as compared to the sham-operated animals. These changes resulted from suppression of the central mechanisms of stress realization due to the lowered steroid metabolism. Intraperitoneal administration of carbon tetrachloride (0.1 ml per 100 g of body weight) at the same periods led to a significant intensification of the steroidogenesis in the adrenal tissue and to the activation of NAD-dependent dehydrogenases in the cytoplasm. The role of toxic injury of the glands in the changes of the functional state of the adrenal cortex cells is discussed.     

Basis for the use of Pierre's method for the determination of ACTH in human blood plasma]

Adrenal glands of rats were immersed in Ringer-Lock solution (used as control), other rat adrenal glands were immersed in human blood plasma. The amount of corticosterone in the extracts received was estimated after two hours of incubation. The activity of adrenocorticotropic function of the pituitary gland of the patients examined was judged by the difference in the corticosterone indices in these extracts. ACTH (1.5 and 10 mkg) was added to the plasma to determine the sensitivity of this technique. Regular and significant increase in corticosterone was revealed. Modified Pierre's technique can be applied for ACTH determination in man.     

The effects of chronic SRIH-14 and octreotide administration on the pituitary-adrenal axis in adult male rats

The effects of chronic treatments with SRIH-14 and octreotide on pituitary corticotropes (ACTH cells) and on the adrenal cortex of male Wistar rats were examined. Adult males received two daily s.c. injections of 20 microg/100 g of body weight of either SRIH-14 or octreotide for 28 consecutive days. ACTH cells were studied using a peroxidase-antiperoxidase immunocytochemical procedure. Morpho-metry was used to evaluate the changes in cell and nuclear volumes (microm3) and volume densities (%) of ACTH-immunoreactive cells. The adrenal cortex was analyzed by histological and morphometric methods. A significant (p<0.05) decrease in body weight and in the absolute weights of the pituitary and adrenal glands was observed in both treated groups. Morphometric parameters of ACTH cells in both treated groups were not significantly (p>0.05) different than in control rats. The absolute volumes of the adrenal gland and adrenal cortex were significantly (p<0.05) decreased in both treated groups. The absolute and relative volumes of the zona glomerulosa (ZG), as well as the cellular and nuclear volumes of the ZG were significantly (p<0.05) decreased in the both treated groups. In rats treated with SRIH-14 and octreotide, the absolute and relative volumes of the zona fasciculata (ZF) and zona reticularis (ZR), as well as their stereological parameters, did not change significantly (p>0.05). The aldosterone levels in the SRIH-14 and ocreotide-treated groups were significantly (p<0.05) decreased - by 13% and 19%, respectively. The concentration of ACTH and corticosterone did not change significantly. Together, these findings show that SRIH-14 and octreotide administration affected the morphological characteristics of the adrenal ZG in a similar manner, and brought about a decrease in plasma aldosterone concentration. These treatments did not affect pituitary ACTH cells or adrenal ZF and ZR functioning.