Nonylphenol effects on the HPA axis of the bioindicator vertebrate, Podarcis sicula lizard.

Nonylphenol (NP) is an endocrine disruptor widely distributed in the environment. It accumulates in the lipids of living organisms and enters the human food chain. The main source of human exposure is expected to be food, drinking water and foodstuff contaminated through leaching from packaging or pesticide formulation applications. NP acts as an estrogenic compound and it is able to mimic the action of estradiol 17ß (E2) by binding to the estrogen receptor (ER). The aim of the present study was to investigate the NP effects on the hypothalamic-pituitary-adrenal gland (HPA) axis of the bioindicator Podarcis sicula lizard. A time-dependent stimulation of the HPA axis and variations of both catecholamine plasma levels were showed. Moreover, NP effects on adrenal gland morphology were evaluated by light and transmission electron microscopy. Clear morphological signs of adrenal gland stimulation such as an increase of steroidogenic cord diameter and vascularization, a strong escalation of adrenaline cell number and a decrease of noradrenaline cells were observed. The notably elevated levels of adrenal hormones suggested a permanent turning on of hypothalamic corticotropin releasing factor (CRF) secretion together with a lack of the negative feedback of HPA axis, perturbing systemic responses of the organism. Our data may help to predict the biological alterations induced by NP and to extend its impact upon adrenal function.

[Effect of drinking boron on microtructure of adrenal gland in rats].

OBJECTIVE: The effects of drinking boron exposure on the mass, organ indexes and structure of adrenal gland were studied in the paper. Methods 192 Sprague-Dawley rats (28 +/- 2 days) with no bacteria infecting were divided into six groups (n = 32, male = female) randomly. Treated rats drunk the distilled water which supplemented with boron of 0, 40, 80, 160, 320 and 640 mg/L, respectively, for 60 days. At the 30th and the 60th day of experiment, 16 rats (n = 8, male = female) of each group were selected and made into narcosis with 10% Chloral Hydrate. The adrenal glands were obtained, weighted and fixed after dissection, then the samples were made into paraffin sections, stained with HE stain and chromaffin, observed and photographed by Olympus CH-30 microphotograph system. RESULTS: Compared with control group, the average mass of adrenal gland of male rats in each experiment group decreased significantly or most significantly at the 30th day of experiment (P < 0.05 or P < 0.01), but the index of adrenal gland of male rats in the group of 640 mg/L boron at 60th day of experiment increased significantly (P < 0.05). Under the microscope, the microstructure of adrenal gland of rats in the group of 40 mg/L boron were better obviously than control group, and the numbers of chromaffin granules in chromaffin cell increased obviously. The histopathological changes of different degree could be observed in the group of 80 to 640 mg/L boron, and they became remarkable with the boron supplementation. By comparative observation, the damage of cells in adrenal medulla appeared ahead of them in adrenal cortex, and the pathological change of adrenal gland in male rats were obvious than female rats. CONCLUSION: Drinking supplemented with 40 mg/L boron could prompt the structure of adrenal gland in rats, but could cause different degree damage, or even obvious toxic effect when the concentration of boron supplementation in drinking from 80 to 640 mg/L.

[Effect of external ionizing radiation on morphofunctional indices of the hypothalamus, hypophysis and adrenal glands]. / Vplyv zovnishn'oho oprominennia na morfofunktsional'ni pokaznyky hipotalamusa, hipofiza i nadnyrkovykh zaloz.

The laboratory rats exposed to one-time external ionizing radiation have been found to have phase changes of morphofunctional and secretory cells activity of hypothalamus, hypophysis, cortex and medullary of adrenal glands. The first phase called reactive (3-7 days) is characterized by enhancing energy-producing, protein-synthesizing and secretory functions of secretory sells of hypothalamus supraoptic nucleus, corticotrophic cells of adenohypophysis, adrenocorticytes of cortex and adrenocytes of medullary of adrenal glands. The second phase of dystrophic changes (7-14) is characterized by different degree of distrophic-destructive changes. The third phase (14-1 month) is characterized by compensatory adaptative and recovery processes during which we can see on the background of dystrophic changes the processes of intracellular reparative regeneration. The fourth phase (1-3 months) is characterized by virtually complete recovery of morphofunctional and secretory activity of most cells of hypothalamus, hypophysis and adrenal glands.

Fine structure of rat liver, adrenal, testis and seminal vesicle in experimental emaciation.

Experimentally emaciated male rats were produced by a bilateral electrical destruction of a part of hypothalamus. In a typical case, when the animals were fixed by perfusion, dissected, and organs weighted, the body weight became 1/2 of the control in 10 weeks. The weight of the viscera (including the subserous fat) was more decreased in comparison with the controls than the weight of the body wall (including extremities and the subcutaneous fat). The weight of the liver became 1/3, the adrenal 1/4, the testis 1/6 and the seminal vesicle 1/19 of the control. Light and electron microscopic examinations showed atrophy and fatty degeneration in the liver, atrophy of the zona reticularis in the adrenal, failure of spermatogenesis, especially at its spermiogenetic stage, in the testis, and an apoptosis in glandular epithelial cells of the seminal vesicle. Two weeks after partial hypothalamus destruction, the weight of the body wall was more decreased in comparison with the controls than the weight of the viscera. Possible pathophysiological mechanisms are discussed. An experimental model of electron microscopical research of apoptosis are presented.

Gene expression of central and peripheral renin-angiotensin system components upon dietary sodium intake in rats.

The effects of dietary sodium intake on the gene expression of the renin-angiotensin system (RAS) were investigated in rat central and peripheral tissues in a single set of experiment. Northern and reverse transcriptase-polymerase chain reaction (RT-PCR) techniques were used to detect mRNA expression in rats fed a low- or a high-sodium diet (5 or 500 mmol Na+/kg diet) for 20 days. Plasma and renal renin levels were elevated in rats maintained on the low-sodium diet. Sodium deprivation enhanced the expression of angiotensinogen, renin, AT1A and AT1B receptor subtypes in the hypothalamus, but suppressed them in the brainstem. Kidney and adrenal levels of those mRNAs were also enhanced in the sodium-restricted rats. Both AT1A and AT1B mRNAs changed in a similar magnitude in each tissue examined upon dietary sodium intake. AT1A was the predominant receptor subtype of AT1 in all the tissues examined in the present study except the adrenal gland. The present study demonstrated that dietary sodium modulated the gene expression of the RAS components in the central and peripheral tissues. It also showed that the RAS components in the brainstem and hypothalamus were differentially expressed upon sodium deprivation. This suggests different roles of the RAS in these tissues in maintaining body fluid homeostasis in response to different sodium intakes.

Thickening of the adrenal zona glomerulosa in dogs induced by oxodipine, a calcium channel blocker.

Subchronic effects of oxodipine, a calcium channel blocker affecting the adrenal gland of the dog, are described. Thirteen wk of treatment at a high dose (24 mg/kg/day) of oxodipine resulted in drug-induced thickening of the zona glomerulosa and increased stimulation of its secretory activity. It is postulated that subchronic administration of oxodipine at this dosage resulted in a decrease in blood pressure, with uninterrupted stimulation of the adrenal zona glomerulosa to release aldosterone, causing an increase in the width of this portion of the gland involving cellular hyperplasia. Support for this indirect effect is found in the increased presence of renin granules in the juxtaglomerular apparatus.

The role of potassium and other ions in the control of aldosterone synthesis.

Fast and slow K+ efflux components, independently regulated by angiotensin II (AII), have been identified in bovine adrenocortical cells. We have further investigated the role of potassium in the control of aldosterone synthesis in two ways. Firstly, isotopic tracers, in conjunction with channel modulators, have been used to study the interrelationship of K+ and Ca2+ in the control of AII-stimulated aldosterone synthesis. Secondly, electron probe X-ray microanalysis (EPXMA) was used to quantify potassium, sodium, chlorine and phosphorous in control and AII-stimulated cells. The effects of verapamil on 43K efflux were measured at two stages during AII stimulation. During the first ten minutes of treatment, when efflux via the fast component predominates, AII and verapamil both slowed efflux and their effects were additive. If verapamil was added later, at the time when efflux by the fast component appeared exhausted and the stimulatory effect of AII on the slow efflux component was apparent, it again slowed efflux. These data suggest that verapamil prevents calcium-gated K+ channels from opening by blocking Ca2+ channels. However, verapamil had no effect on AII-stimulated calcium efflux. In addition to blocking Ca2+ channels, verapamil may directly inhibit potassium efflux. EPXMA showed a bimodal distribution of potassium concentrations in control cells. However, in cells stimulated with AII for five minutes, the mean potassium content was less than in controls and was not bimodally distributed. Sodium content was increased by AII-treatment, chlorine was lowered and phosphorus remained unchanged. The data confirm previous observations that AII inhibits Na+/K+ ATPase activity.

[Effect of the N-terminal fragment of substance P1-4 on the somatic manifestations of the stress reaction and on the catecholamine content of the adrenals in rats]. / Vliianie N-terminal'nogo fragmenta substantsii P1-4 na somaticheskie proiavleniia stressovoi reaktsii i soderzhanie katekholaminov v nadpochechnikakh krys.

The antistress affect of the substance P1-4 N-terminal fragment (ARG-Pro-Lys-Pro, 100 mkg/kg, i.p.) has been studied on the model of immobilization stress in rats. It was ascertained that the preparation of protective effect is revealed to the greatest extent on the exhaustion stage (48 h of immobilization), which served to prevent the lymphoid organs mass reduction and ulcer development and also accounted for greater adrenaline and noradrenaline content preservation in tissues and chromaffin cells of adrenal glands in stressed animals.

[Ultrastructure of the adrenal glands in rats under stress after preliminary use of the biostimulator "Biomos"]. / Ul'trastruktura nadpochechnykh zhelez krys pri stresse posle predvaritel'nogo primeneniia biostimuliatora biomosa.

Adaptogenic influence of biostimulator "Biomos" on the course of stress-reaction in adrenal glands has been shown by the electron-microscopic method. It consists in essential reconstructions of steroidogenesis apparatus directed to potentiation of mineralocorticoid function and to stabilization of the glucocorticoid function as well as to maintenance of structural integrity of substantia medullaris.

Effect of lifelong selenium and vitamin E deficiency or supplementation on pigment accumulation in rat peripheral tissues.

The accumulation of lipopigments during aging in several peripheral organs and in the nervous system is considered to be related to the peroxidation of unsaturated fatty acids. In this study the effect of lifelong (until to 18 months) dietary antioxidants selenium and vitamin-E on pigment accumulation in some peripheral tissues was estimated using fluorescence and electron microscopy. In the vitamin E deficiency group, there was increased pigment accumulation in all peripheral tissues studied except the hypogastric ganglion, where no change was observed. The vitamin E supplementation degreased the pigment accumulation in older animals in some of the tissues studied. At the electron microscopical level the accumulated pigment in the adrenal cortex showed a lipofuscin-like structure. Lifelong selenium supplementation or deficiency did not significantly alter pigment accumulation in any of the tissues studied. It is possible that in many organs dietary selenium may not play a critical role in lipofuscin formation.

[Morphofunctional characteristics of adrenal reactivity in rats of different ages]. / Morfofunktsional'nye osobennosti reaktivnosti nadpochechnikov krys raznogo vozrasta.

Ultrastructural peculiarities of the cortical and medullary substance of the adrenals have been studied in mature (8-month-old) and old (26-month-old) intact white male rats and in rats of the same age groups in 3 h after electrical stimulation of the hypothalamic ventromedial nuclei. By means of certain biochemical methods contents of hormones (corticosterone, adrenaline and noradrenaline) have been estimated, as well as that of cholesterin and ascorbic acid in blood and adrenal tissues. After the hypothalamus is stimulated in the mature rats, certain peculiarities in the adrenals reactivity are revealed; they demonstrate positive ultrastructural and functional correlation of secretory cells in the cortex and medulla and are characterized with hypertrophy of the nuclei, increased amount of polyribosomes, hypertrophied Golgi complex and canaliculi of the endoplasmic reticulum and increased contents of corticosteroids and catecholamines in blood. In the old rats after stimulation of the hypothalamus, certain unequal ultrastructural and functional peculiarities are revealed. They demonstrate both disturbance of the hypothalamic regulation of the adrenal function at ageing and decreased adaptive possibilities of the adrenal secretory cells at the subcellular level.

Light and electron microscopical visualization of selenium in adrenal glands from rats exposed to sodium selenite.

A histochemical study was performed to determine the cellular localization of selenium in the adrenals from rats exposed to sodium selenite, as these organs were known to obtain the highest concentration in the rats. Male rats were treated either with 1-15 mg of sodium selenite for 14 days to 6 months in the drinking water, or with 1-20 mg as intraperitoneal injections. Selenium was shown to accumulate in both norepinephrenic and epinephrenic cells in a dose-dependent fashion. After oral exposure most deposits were found in the epinephrenic cells, whereas the norepinephrenic cells contained most in the injected animals. Fourteen days after a single injection (4 mg/kg), deposits could still be observed in the granules of the chromaffin cells. At the ultrastructural level, accumulations were primarily found in the chromaffin granules and to a lesser extent in the lysosomes. Selenium may possibly form bonds to endogenous zinc in the adrenals as has been suggested for the brain.

Clinical, gross, and histological findings in herring gulls and Atlantic puffins that ingested Prudhoe Bay crude oil.

Oral doses of 0, 1, 4, 5, 10, or 20 ml of Prudhoe Bay crude oil/kg body weight/day were given to herring gull and Atlantic puffin nestlings for 5 to 7 consecutive days. Gulls defecated substantial amounts of oil within 10 to 15 minutes after receiving a dose. Clinical signs and lesions occurred only in birds given greater than or equal to 10 ml oil/kg body weight/day. Gulls consumed less food and lost weight. Two categories of lesions were observed: those considered secondary to a primary toxic hemolytic disease, and those considered nonspecific reactions to stress. The former included phagocytosis of degenerate erythrocytes in the liver and spleen, hemoglobin resorption droplets in renal proximal tubule cells, and erythroid hyperplasia in the bone marrow; the latter included lymphocyte depletion in primary lymphoid tissues, an increase in heterophil: lymphocyte ratio in peripheral blood, lipid depletion and necrosis in adrenal steroidogenic cells, and an increased prevalence and severity of lesions in the bursa of Fabricius. These findings indicated that the primary target of oil toxicity was the peripheral red blood cell, but that significant stress-related lesions were also associated with ingestion of oil.

[Effect of unithiol on the ultrastructure of the myocardium and adrenals in endotoxin shock]. / Vliianie unitiola na ul'trastrukturu miokarda i nadpochechnikov pri éndotoksinovom shoke.

Administration of unithiol to animals with endotoxin shock promotes deposition of catecholamines in chromaffin cells of the adrenals, blocks their secretion to the bloodstream and prevents the development of injuries to the cortical substance of the gland. Administration of unithiol for endotoxemia prevents damage to intracellular organelles of cardiomyocytes. However, insignificant disorders of the contractile apparatus of the cells and histohematic barriers are maintained. The capacity of unithiol to prevent the progress of destructive alterations in the heart and adrenals permits recommending it for use in combined treatment of septic conditions.

Age changes in the ultrastructure and function of rat adrenal glands during stimulation of the hypothalamus.

Studies were undertaken on the ultrastructure and function of the adrenal cortex and the adrenal medulla three hours after an electric stimulation of the ventromedial nucleus area of the hypothalamus in the adult and old albino rats. The electron microscopic and biochemical findings revealed a significant decrease in the hypothalamic control over catecholamine and corticosteroid syntheses in the old rats. The regulatory influence of the hypothalamus on the secretory activity of the adrenocortical and adrenomedullar cells showed an irregular pattern of changes during aging, i.e. a more marked impairment of the adrenal medulla and a less marked impairment of the cortex.

Cushing's syndrome with bilateral multinodular adrenal hyperplasia. Ultrastructural, histochemical, and immunohistochemical study.

An unusual case of Cushing's syndrome of a 59-year-old man with bilateral multinodular adrenal hyperplasia and microadenoma of the pituitary gland is presented. Failure to suppress plasma cortisol with large doses of dexamethasone may suggest autonomous growth of hyperplastic nodules of the adrenals, which were at first induced by prolonged stimuli of ACTH from the microadenoma of the pituitary gland. ACTH could not be detected in the microadenoma cells on paraffin sections, while Crooke's cells were strongly positive for ACTH. The interrelation between bilateral multinodular adrenal hyperplasia and pituitary microadenoma is discussed.

Adrenal and hepatic calcium stearate crystal deposits in dogs fed a thiamine-deficient diet.

The nature and histologic environment of birefringent crystals found incidentally at necropsy in the liver and adrenal glands of dogs fed a thiamine-deficient diet were studied. The crystals were identified as calcium stearate by ultrastructural and x-ray microdiffraction techniques. Crystals were observed intracellularly within cytoplasmic vacuoles and extracellularly within sinusoids. Generally, crystals were also observed in pair-fed controls that were given a purified diet (equal in weight to that consumed by the thiamine-deficient animals) plus supplemental thiamine. Crystal deposits were found in trace amounts in a few of the ad libitum-fed controls. Although thiamine deficiency may be involved in promoting crystal deposition in the adrenal cortex, calcium stearate crystal formation within the adrenal glands and the liver appears unrelated to dietary thiamine deficiency per se, but is probably related to deficiency of an unidentified nutrient in the purified thiamine-deficient diet.

Generalized lipidosis in newborn rats and Guinea pigs induced during prenatal development by administration of amphiphilic drugs to pregnant animals.

Pregnant rats and guinea pigs were treated throughout the second half of gestation with amphiphilic drugs (chlorphentermine, chlorcyclizine, chloroquine) known to induce generalized lipidosis. The offspring were sacrificed immediately after birth, and several tissues (lung, liver, kidney, spleen, pituitary gland, adrenal gland, spinal cord, hypothalamus) were examined by electron microscopy. Generalized lipidosis was found in the offspring of both species, albeit of lesser degree than in the mothers. The results show that fetal and adult tissues respond to lipidosis-inducing drugs in a qualitatively similar way; the quantitative differences found may be related to pharmacokinetic and cellular factors.