Analysis of the role of glycolysis in the response of adrenal cells to ACTH

The dynamics of steroid formation was found to coincide with that of lactic acid synthesis during perfusion of rat adrenal slices with ACTH. Inhibition of glycolysis by monoiodoacetate prevented the development of the specific effect of ACTH; the effect was restored on the addition of pyruvate to the medium. A decrease in the P/O ratio was found in the adrenal slices under the influence of ACTH, progesterone, and deoxycorticosterone (DOC). Steroid formation was inhibited by 2,4-dinitrophenol (2,4-DNP). The possibility of secondary activation of glycolysis in the adrenals under the influence of ACTH by a mechanism of self-regulation of the glycolytic chain through a decrease in the phosphate potential of the cell is discussed.Central Scientific-Research Laboratory, Novosibirsk Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR, V. P. Kaznacheev) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 78, No. 9, pp. 50–52, September, 1974.     

Mechanisms of the primary response of the adrenal cortex to pain stress in dogs

A sharp decrease in the glucocorticoid content accompanied by an increase in the free cholesterol and a decrease in the content of esterified cholesterol were observed in the adrenal cortex of dogs 10–15 sec after nociceptive stimulation. The blood concentrations of the hormones were increased, mainly due to the proteinbound hydrocortisone fraction. The next phase of the response (30–60 sec after stimulation) was marked by activation of synthetic processes, leading to considerable accumulation of hormones in the gland. The blood glucocorticoid level was doubled, the original ratio of hydrocortisone to corticosterone was restored, and the transcortin depot was replenished. The role of the adrenal and transcortin deports of glucocorticoids in the feedback mechanism during stress is discussed.Department of Pathological Physiology, Rostov Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR V. K. Kulagin.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 88, No. 7, pp. 18–20, July, 1979.     

An ELISA method for the detection of autoantibodies to adrenal cortex

An enzyme-linked immunosorbent assay (ELISA) is described for autoantibodies to adrenal cortex. Microsomes were prepared from fresh human adrenal glands, and microtitre ELISA plates were incubated at 4 degrees C overnight with 25 micrograms antigen/ml, the optimal concentration for the system. Optimal dilution of patient's serum was 1/500. Peroxidase-labelled anti-human IgG and IgM sera were used in separate tests and o-phenylenediamine and H2O2 served as substrate. Intra-assay variance of optical density units was 4.5%, and inter-assay variance was negligible when antigen preparations from 2 different adrenal glands were compared. All sera positive or negative at first test gave the same qualitative result in a second. Non-organ-specific binding of sera containing mitochondrial or ribosomal antibodies was eliminated by a blocking ELISA system where the antigen-coated plates were incubated with test sera, and in a second step, peroxidase-labelled IgG from an adrenal antibody-positive control serum was added. In this test, optimal antigen concentration for coating of plates was 6.25 micrograms/ml and optimal serum dilution 1/50. The ELISA proved more sensitive and reproducible than indirect immunofluorescence. Adrenal antibodies detected by ELISA were usually of IgG class alone and only 1 of the 30 positives also contained IgM specificity. 30 out of 38 sera (79%) from patients with 'idiopathic' Addison's disease were positive whereas immunofluorescence revealed only 23 (61%) at first testing and another 4 positives when sera were tested on different adrenal glands. The ELISA described is useful for both scientific work and clinical diagnosis of autoimmune adrenalitis.     

Investigations into the nature of the dexamethasone and ACTH effects upon learned taste aversion

Dexamethasone injected prior to the conditioning trial will attenuate a learned taste aversion. ACTH injections will prolong the recovery from a taste aversion when administered prior to recovery trials. Two experiments are reported here. In the first, the interaction between these effects was studied. Using a factorial design, four groups of rats received dexamethasone or ACTH prior to conditioning and prior to recovery trials. An additional group received isotonic saline throughout training and recovery. The primary finding was that animals receiving dexamethasone prior to conditioning and ACTH prior to recovery trials did not differ from the group pretreated with ACTH during both conditioning and recovery. That is, given the parameters of these experiments, the ACTH effect was prepotent. In the second experiment it was shown that the ACTH effect upon the performance of a taste aversion can occur in one trial. Taken together, the results of the two experiments support the idea that ACTH influences memory retrieval when administered prior to a test for retention of an avoidance response.     

Some relationships between adrenal function and the effectiveness of a period of isolation in inducing intermale aggression in albino mice

Because an inverse relationship has been demonstrated by numerous authors between aggressiveness and adrenal function in rodents, a series of experiments, in which manipulations of the pituitary/adrenal axis were carried out, was undertaken to determine whether this had any modulating influence on fighting behavior. The effects of adrenalectomy, dexamethasone blocking of the pituitary and of ACTH injection on isolation-induced aggression in the immature, naive and the mature, sexually experienced male albino laboratory mouse are described. It was found that whilst adrenalectomy reduced aggression, dexamethasone blocking enhanced it and ACTH injection reduced it, although the differences were not always significant. The possible mode of action of ACTH in reducing aggression and the consequences to natural populations of rodents is discussed.     

硒对胃癌大鼠肾上腺皮质3β-HSD和SDH组织化学的影响

目的：观察硒在预防大鼠实验性胃粘膜癌变过程中肾上腺皮质组织化学的变化。方法：用断乳雄性Wistar大鼠，分为盐水对照组、N-甲基N—硝基—亚硝基胍(MNNG)和Selenite十MNNG组，用组织化学和图像分析方法观察大鼠肾上腺皮质的变化。结果：补硒组大鼠肾上腺皮质束状带和网状带细胞内琥珀酸脱氢酶(SDH)和3β—羟基类固醇脱氢酶(3β—HSD)的组化反应减弱，与MNNG组相比有显著性差异，与对照组相比略有增加，但无统计学意义。MNNG组大鼠SDH和3β—HSD的反应增强，与对照组相比有显著性差异。结论：硒在预防大鼠实验性胃癌过程中，可能参与了肾上腺皮质功能的调节。     

Low dose dexamethasone reverses depressive-like parameters and memory impairment in rats submitted to sepsis

Sepsis is characterized by a systemic inflammatory response of the immune system against an infection, presenting with hypothalamic–pituitary–adrenal (HPA) axis dysfunction, behavior alterations, and high mortality. In this study, we aimed to evaluate the effects of dexamethasone on mortality, anhedonia, circulating corticosterone and adrenocorticotropin hormone (ACTH) levels, body and adrenal gland weight, and aversive memory in sepsis survivor rats. Male Wistar rats underwent sham operation or cecal ligation and perforation (CLP) procedure. Rats subjected to CLP were treated with “basic support” and dexamethasone (at 0.2 and 2 mg/kg daily for 7 days after CLP, intraperitonially) or saline. After 10 days of sepsis procedure, it was evaluated aversive memory, sweet food consumption, and body and adrenal gland weight. Serum and plasma were also obtained. It was observed that low dose dexamethasone reverted anhedonia, normalized adrenal gland and body weight, corticosterone and ACTH levels, and decreased mortality and avoidance memory impairment, demonstrating that low doses of dexamethasone for moderate periods may be beneficial for sepsis treatment and its sequelae—depressive-like parameters and memory impairment.     

Stimulation of the prelimbic cortex differentially modulates neuroendocrine responses to psychogenic and systemic stressors

The medial prefrontal cortex is important for normal regulation of stress responses, and is implicated in stress-related affective disease states (e.g. depression). In the current study, we investigated the role of the prelimbic division of the prefrontal cortex in control of responses to psychogenic and systemic stressors (restraint and hypoxia, respectively). Acute stimulation of the prelimbic cortical region with bicuculline methiodide (BMI) caused significant reduction of ACTH and corticosterone responses to restraint and reduced Fos activation of paraventricular nucleus neurons, consistent with a role in central inhibition of acute psychogenic stress responses. In contrast, BMI enhanced corticosterone (but not ACTH) responses to hypoxia via a mechanism suggestive of central PVN drive and enhanced adrenal sensitivity. Acute BMI increased restraint stress-induced Fos activation in known downstream targets of the prelimbic cortex (e.g., the basolateral amygdala and central amygdaloid nuclei), suggesting a connection between modulation of amygdalar signaling and stress inhibition. In contrast, hypoxia caused robust Fos activation in the basolateral and central amygdala, which was not affected by prelimbic BMI injection. The data suggest that the prelimbic cortex stimulation is sufficient to trigger inhibition of the HPA axis to psychogenic stress, but may play a very different role in enhancing HPA responsiveness to physical threats.     

Adrenocortical influences upon the extinction of an appetitive runway response

Sprague-Dawley rats received daily injections of either ACTH, hydrocortisone, corticosterone, or placebo throughout the acquisition and extinction of a food-reinforced runway response. The results showed that hormone injections produced no systematic effects upon acquisition performance. Injections of either hydrocortisone or corticosterone, however, produced faster running on early extinction trials as compared to either ACTH or placebo injection. There was some suggestion that increased corticosteroid levels, rather than some change in ACTH levels, produced the effects upon extinction responding.     

Morpho-physiological changes in the adrenal cortex and thymus during growth of a transplanted glioblastoma multiforme in the rat brain

A study of the morpho-physiological changes in the adrenal cortex and thymus growth of a transplanted glioblastoma multiforme in the rat brain revealed marked activation of the glucocorticoid function of the adrenal cortex accompanied by inhibition of thymic function. In aniamsl not developing the disease activation of the thymic reticulo-epithelium was observed whereas the indices of adrenocortical function remained within normal limits.Laboratory of Age Pathology and Laboratory of Histopathology of the Central Nervous System, Institute of Human Morphology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR A. P. Avtsyn.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 78, No. 10, pp. 111–114, October, 1974.     

Sex differences in the effects of dexamethasone phosphate on behavior in rats.

The effect of dexamethasone phosphate (DEX) administered in rats' drinking water on running activity and open field behavior was investigated. In Experiment 1 males were given DEX continuously from either five days or one day prior to and throughout testing. Only 5 day treatment significantly increased running wheel activity. DEX had no significant effect on males' 4 day open field activity, but significantly reduced open field and home cage defecation. In Experiment 2 females given DEX defecated significantly more in the open field than controls. This effect on females does not appear to be due to a general metabolic change, since DEX females, like males, defecated significantly less than controls in the home cage. Females' open field activity was not significantly affected. Weight loss and plasma corticosterone analysis confirmed the effectiveness of the dosage used. There appears to be a sex difference in the effects of DEX on open field defecation, possibly due to interaction with gonadal hormones.     

Influence of melatonin and sexual hormones on the expression of proliferating cell nuclear antigen in the adrenal cortex of a seasonal breeder (Lagostomus maximus)

The viscacha (Lagostomus maximus) is a rodent of nocturnal habits, whose physiology and behavior vary according to modifications of environmental signals. The objective of this study is to assess the influence of melatonin and sexual hormones on the viscacha adrenal cortex proliferative activity through the immunohistochemical detection of proliferating cell nuclear antigen (PCNA) along with hormonal determinations. PCNA expression was studied in male viscachas to assess the effect of melatonin administration, castration, and the annual reproductive cycle. In female viscachas, PCNA was studied in nonpregnant and pregnant viscachas. PCNA expression was observed in adrenocortical cells (PCNA-A) and endothelial cells (PCNA-E). Melatonin-administered animals showed a significantly lower number of PCNA-A compared to the control group. No significant difference could be established in the number of PCNA-A and PCNA-E between castrated and control animals. However, the morphometric analysis showed an increase in the size of the cortex of castrated animals, along with other cytological features. Significant differences in serum testosterone levels were observed during the male viscacha reproductive cycle, with the lowest levels encountered during the regression period (winter). Male viscachas exhibited a significantly high number of PCNA-A during late autumn and a high number of PCNA-E during winter. In females, hormonal determinations showed a peak of progesterone and estrogen during mid-pregnancy, along with a notably high number of PCNA-A and an increase in the number of PCNA-E. Our results suggest that proliferation in the adrenal cortex of the viscacha varies in relation to melatonin, sexual hormones, and environmental conditions.     

Effect of direct exposure to low-intensity laser radiation on morphology and function of the zona fasciculata of the albino rat adrenal cortex

Medico-Biological Department, Research Institute of Laser Surgery, Moscow. Department of Histology, Smolensk Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR V. V. Kupriyanov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 109, No. 6, pp. 598–600, June, 1990.