Immunologic reactivity of the body and the adrenal cortex function in the early period after administration of a carcinogen

The level of immunological reactivity and the functional state of the adrenal cortex were studied simultaneously in BALB/c mice 7 days after a single injection of various doses of methylcholanthrene. There existed a definite correlation between the immunodepression induced by various doses of methylcholanthrene determined according to the amount of plaque-forming cells in the experimental mouse spleen and free and combined 11-corticosteroids content in the blood plasma after 7 days of the carcinogen injection. This evidence suggests that the adrenal cortex hormones play a definite role in the pathogenesis of immunodepression induced by chemical carcinogenesis.     

Catecholamine content and electrolyte balance of the rabbit myocardium during poisoning with 2,4-dinitrophenol]

At the initial stages of energy deficiency in rabbits caused by an intravenous injection of 2,4-dinitrophenol (10 mg/kg) there occurred in the cardiac ventricles an increase in the noradrenalin content and a fall in the potassium level. In case of a more pronounced energy deficiency (20 and 30--40 mg/kg of 2,4-dinitrophenol) noradrenaline stores in the heart became exhaustated, whereas the potassium level in the myocardium became greater. There is a fall of adrenaline stores in the heart, whereas the potassium level in the myocardium increased. The amount of adrenaline in the heart and the adrenal glands decreased. Deep energy deficiency is accompanied by the syndrome of hyperkaliemia associated with the exit of potassium into the blood from the depot tissues.     

Response of the adrenals to stress in animals from litters with different numbers of young.

Undernutrition and overnutrition during the suckling period -- achieved by adjusting the number of infant rats per litter to 4, 8 and 14 -- resulted in a decrease in the plasma corticosterone level and in corticosterone production by the adrenals in vitro in overfed animals at the age of 30, 180 and 300--360 days. An enhanced response to ether anaesthesia or immobilization stress was found in overfed animals from the smallest litters. The results show that a change in postnatal nutrition and in social relationships in the litter influences maturation of the hypoathalamo-hypophysio-adrenal regulatory system; in adulthood this is manifested in changes in production of the adrenal hormones and in the reaction of the adrenals to stress.     

In vivo regulation of ovarian activity by alpha-fetoprotein

Adult female rats, each injected with 760 microgram alpha-fetoprotein (AFP) weekly, presented after the third week a decrease of ovarian activity evidenced by a decreased number of maturing follicles, corpora lutea, and a drop in ovarian weight. The level of progesterone was low and agreed with the decreased number of corpora lutea. Conversely, total and free estradiol-17 beta levels remained normal despite the known ability of AFP to bind estrogenic hormones. A regulatory role of AFP during the postnatal stage of sexual maturation is proposed.     

Age-dependent changes in the concentration of active sex steroids,precursors, metabolites,and regulatory agents in blood serum of male subjects

We measured blood concentration of active and non-active sex steroids, metabolites, and precursors and compared to changes in protein and peptide hormones controlling the reproductive axis (total 14 hormones and hormone-like substances) in male subjects aged 18 to 72 y.o. We found a significant decrease in serum concentration of precursors for active sex steroids (pregnenolone, progesterone, dehydroepiandrosterone, and DHEA-sulfate), free testosterone, androstenedione (non-active metabolite of testosterone) as well as 5α-dihydrotestone after the age of 35. However, the level of total testosterone and estradiol (another active testosterone metabolite) remained steady. The systems regulated production of active sex steroids resisted a higher load associated with age and caused the increase in luteinizing and follicle-stimulating hormones in hypophysis and activin in steroidogenic glands directly correlating with age; negative correlation for these hormones was confirmed with certain sex steroids explaining the negative feedback. Decrease in level of hypopheseal adrenocorticotropic hormone with age demonstrated a more substantial role for adrenal glands compared to that of testicles in reduction of blood concentration of active sex steroids. In general, despite the reduced activity of steroidogenic glands in 60-to 70-year old male subjects the level of testosterone and estradiol remained unchanged due to associated growth of level of luteinizing and follicle-stimulating hypopheseal hormones as well as activin in steroidogenic glands that stimulated biosynthesis of sex steroids. Also androgen effects were inhibited due to the reduced level of free (unbound) testosterone and 5α-dihydrotestone.     

Role of PAC(1) receptor in adrenal catecholamine secretion induced by PACAP and VIP in vivo

The present study was conducted to investigate the functional implication of the pituitary adenylate cyclase-activating polypeptide (PACAP) type I (PAC(1)) receptor in the adrenal catecholamine (CA) secretion induced by either PACAP-27 or vasoactive intestinal polypeptide (VIP) in anesthetized dogs. PACAP-27, VIP, and their respective antagonists were locally infused to the left adrenal gland via the left adrenolumbar artery. Plasma CA concentrations in adrenal venous and aortic blood were determined by means of a high-performance liquid chromatograph coupled with an electrochemical detector. Adrenal venous blood flow was measured by gravimetry. The administration of PACAP-27 (50 ng) resulted in a significant increase in adrenal CA output. VIP (5 microg) also increased the basal CA secretion to an extent comparable to that observed with PACAP-27. In the presence of PACAP partial sequence 6--27 [PACAP-(6--27); a PAC(1) receptor antagonist] at the doses of 7.5 and 15 microg, the CA response to PACAP-27 was attenuated by approximately 50 and approximately 95%, respectively. Although the CA secretagogue effect of VIP was blocked by approximately 85% in the presence of PACAP-(6--27) (15 microg), it remained unaffected by VIP partial sequence 10--28 [VIP-(10--28); a VIP receptor antagonist] at the dose of 15 microg. Furthermore, the CA response to PACAP-27 did not change in the presence of the same dose of VIP--(10--28). The results indicate that PACAP-(6--27) diminished, in a dose-dependent manner, the increase in adrenal CA secretion induced by PACAP-27. The results also indicate that the CA response to either PACAP-27 or VIP was selectively inhibited by PACAP-(6--27) but not by VIP-(10--28). It is concluded that PAC(1) receptor is primarily involved in the CA secretion induced by both PACAP-27 and VIP in the canine adrenal medulla in vivo.     

DOLPHIN THYROID AND ADRENAL HORMONES: CIRCULATING LEVELS IN WILD AND SEMIDOMESTICATED TURSIOPS TRUNCATUS, AND INFLUENCE OF SEX, AGE, AND SEASON

Biological and environmental influences on circulating adrenal and thyroid hormones were investigated in 36 wild and 36 semidomesticated Atlantic bottlenose dolphins, Tursiops truncatus, matched by age, sex, and time of year when the samples were collected. Serum concentrations of thyroxine (free [fT41 and total [tT4]), triiodothyronine (free [fT3], total [tT3], and total reverse [rT37), cortisol, and aldosterone were determined by radio-immunoassay, Wild female dolphins had significantly higher levels of tT4, fT4 and fT3, an effect that was possibly related to reproduction and lactation. Semidomesticated females had higher tT3 than their wild counterparts. fT4 declined with age in wild dolphins, whereas rT3 was greatest in the older animals. Cortisol and aldosterone were both higher in wild animals sampled after a variable interval of up to four hours after encirclement by capture net. The pattern of adrenal hormone release suggested a mild stress response. Levels of both adrenal hormones were low in semidomesticated dolphins conditioned to present voluntarily their tails for blood sampling, an approach that appears to yield specimens representative of resting values for these constituents.     

Selective stimulation by cinnamaldehyde of progesterone secretion in human adrenal cells

AimsCinnamon bark has been used to treat menstrual pain and infertility. While several pharmacological studies have suggested anti-inflammatory properties, the mechanisms by which the herb exerts its various activities have not been well understood. Recent reports suggest menstrual distress is related to higher estradiol levels, higher estradiol/progesterone ratios. Cinnamaldehyde, a major active constituent of Cinnamomum cassia has been shown to stimulate cathecholamine release from adrenal glands. The objective of the present study is to examine whether cinnamaldehyde stimulates secretion of progesterone and other steroid hormones in human adrenal cells.Main methodsHuman adrenal cells, H295R were exposed for 24 h in a serum-free medium to various concentrations of cinnamaldehyde. Steroid hormones in the cultured medium were measured by a highly sensitive LC-electrospray ionization-tandem mass spectrometry.Key findingsExposure to cinnamaldehyde increased progesterone release in a dose-dependent manner. Testosterone and dehydroepiandrosterone concentrations decreased in the presence of cinnamaldehyde. The release of cortisol or estradiol was not affected by treatment with cinnamaldehyde. cAMP in the cultured medium was increased from 0.06 ± 0.0007 pmol/ml to 0.12 ± 0.0028 pmol/ml by exposure to cinnamaldehyde. The addition of isobutylmehtylxanthine, a phosphodiesterase inhibitor, caused a doubling of the amount of cAMP up to 0.397 ± 0.036 pmol/ml in the presence of cinnamaldehyde.SignificanceThese data suggest that cinnamaldehyde selectively induced progesterone production and inhibited production of testosterone and dehydroepiandrosterone in human adrenal cells.     

Laboratory Drop Towers for the Experimental Simulation of Dust-aggregate Collisions in the Early Solar System

For the purpose of investigating the evolution of dust aggregates in the early Solar System, we developed two vacuum drop towers in which fragile dust aggregates with sizes up to ~10 cm and porosities up to 70% can be collided. One of the drop towers is primarily used for very low impact speeds down to below 0.01 m/sec and makes use of a double release mechanism. Collisions are recorded in stereo-view by two high-speed cameras, which fall along the glass vacuum tube in the center-of-mass frame of the two dust aggregates. The other free-fall tower makes use of an electromagnetic accelerator that is capable of gently accelerating dust aggregates to up to 5 m/sec. In combination with the release of another dust aggregate to free fall, collision speeds up to ~10 m/sec can be achieved. Here, two fixed high-speed cameras record the collision events. In both drop towers, the dust aggregates are in free fall during the collision so that they are weightless and match the conditions in the early Solar System.     

Intracellular free calcium in rat anterior pituitary cells monitored by fura-2

Rat anterior pituitary cells, loaded with the calcium indicator dye fura-2 after primary culture, were challenged with prolactin and growth hormone secretagogues and inhibitory hormones. To initially validate the technique, the calcium channel activator maitotoxin effectively increased intracellular free calcium [( Ca++]i). Various concentrations of the secretagogues thyrotropin releasing hormone or angiotensin II induced peak increases in [Ca++]i within 15 sec, followed by a lower and prolonged plateau phase. The inhibitory hormones dopamine and somatostatin maximally reduced [Ca++]i by 15-20 sec, followed by a spontaneous return to baseline over 5-10 min. The receptor antagonists saralacin and spiperone blocked the angiotensin II and dopamine effects, respectively. Thus, fura-2 appears to be an adequate probe for resolving second-to-second changes in [Ca++]i induced by hormone receptor activation in anterior pituitary cells.     

The effect of adrenal denervation on the metabolic effects of hyperammonemia in sheep

The metabolic effect of intravenous infusion of ammonium chloride (60 mumol/(kg body weight.min] was compared in five sheep before and after adrenal denervation. Adrenal denervation completely abolished the hyperglycemic effect of ammonium chloride, diminished the rise of pyruvate and lactate concentration, and failed to influence the lipolytic effect of NH4Cl. It is suggested that the metabolic effects of ammonia are in a different degree related to the action of ammonia on the central nervous system and (i) the hyperammonemic effect of ammonia completely depends on the neurogenic increase of adrenal medullary hormones; (ii) the rise of blood lactate and pyruvate level observed during hyperammonemia is only partially mediated by adrenaline; and (iii) the lipolytic effect of ammonia ion does not depend on the nerve-controlled secretion of adrenal medullary hormones.     

Ultrastructure of the zone fascicularis of the adrenal cortex of the rat after a single physical loading to fatigue and in the recovery period

Ultrastructure of the fascicular zone in the cortex of the adrenals has been studied in untrained rats after a single physical loading (swimming with an additional load up to fatigue) and during restorative period (24, 48, 72 and 96 h of rest after the loading). The massive release of hormones during the prolonged physical work, as well as during the 1st and the 3d days of rest are estimated by ultrastructural changes in adrenocorticocytes. Signs of an increased permiability of the histohematic barrier in the gland are mostly manifested in 48 h after the loading: in the wall of the smallest vessels ruptures and discharge of formed elements of blood into the pericapillary space; numerous macrophages in the intercellular space phagocytaze the products of degeneration; residual bodies, fragments of decaying cells are seen in the blood capillary lumen. In 96 h of rest, in the fascicular zone of the adrenal cortex changes directed to restoration of the cholesterin depot are observed.     

Adrenomedullary hormonal stimulation and hyperglycemia following intermale aggression in the bandicoot rat

The aim of the present investigation is to evaluate adrenomedullary hormones and blood glucose responses to intermale aggression in the bandicoot rat. Aggression elicited a rise in adrenaline and noradrenaline content of the adrenal gland and in blood glucose level in the subordinate rats. No significant change was marked in the dominant rats after aggression. It is suggested that during aggression the subordinate rats suffered from psychosomatic stress that resulted in hyperactivity of the adrenal medulla and consequently hyperglycemia.     

Hormonal changes associated with leaf senescence in cotton (Gossypium barbadense)

To study the hormonal regulation of foliar senescence in cotton ( Gossypium barbadense L. cv. Giza 68, long staple), the sequential changes in gibberellins (GAs), indoleacetic acid (IAA) and abscisic acid (ABA) were examined in the cotyledons from the completion of expansion through senescence (days 12-24 after sowing). The onset of senescence could be detected on day 20, the stage of maximum accumulation of leaf metabolites. At this stage, free GAs quickly lost more than 40% of their initial activity. Further decrease of free GAs was then characteristically observed in the senescent leaves. A remarkable increase in free IAA and free ABA between days 18 and 20 immediately followed by nutrient depletion, suggests the contribution by both hormones to the senescence system. The definite drop in free IAA below its initial level occurred on day 24, when most of the leaf protein and chlorophyll were already broken down.     

Changes of regional myocardial blood flow during and after acute focal experimental ischaemia.

The regional blood flow through the myocardium of the left ventricle was measured in 11 dogs after ligation of the left anterior descending coronary artery, by means of a local injection of 133Xe depot and precordial detection of its washout 2 hours after ligation. Immediately after ligation the blood flow in the ischaemic area declined considerably but at the same time there was a significant increase of blood flow in the non-ischaemic left ventricular myocardium. The regional flow in the ischaemic and non-ischaemic area increased insignificantly for 2 hrs. These changes were not due to alterations in coronary artery pressure, as the mean arterial pressure declined significantly during the first hour. After temporary ischaemia by ligation of the left anterior descending coronary artery for 2--4 minutes, an intensive reactive hyperaemia developed in the ischaemic region (the blood flow reached 221% of control values on the average) which was the more intensive, the greater the drop of blood flow in the ischaemic area after ligation.     

ACTH-induced ultrastructural changes in the zona fasciculata of the hamster adrenal cortex. Are intraadrenal thrombi regulators of corticosteroid secretion?

Correlated stereological and functional studies were performed on the effect of massive ACTH doses on adrenal cortex of the female hamster. ACTH resulted in a marked increase in adrenal gland weight at day 6 of treatment followed by a drop at day 9. Stereology showed significant enlargement of the zona fasciculata (ZF) cells with the highest value at day 6 and subsequent drop at day 9 of treatment. This hypertrophy was due to a notable increase in the volume of mitochondrial, SER, Golgi apparatus and lipid droplet compartments. Cortisol secretion by adrenal slices and homogenates was also highest at day 6 of ACTH administration and notably lower at day 9. At day 6 of ACTH treatment in outer ZF thrombi were seen. In their vicinity the subendothelial space was dilated and endothelial cells dissociated from the basal lamina. Numerous erythrocytes were also visible among dissociated ZF cells. At day 9 of experiment in outer part of ZF numerous spaces devoid of parenchymal cells appeared. The earlier authors considered the "empty spaces" or "holes" in hyperstimulated adrenal cortex as a sign of holocrine secretion of steroid hormones. The present findings enable us to introduce a new hypothesis on the development of these spaces. In our opinion in hyperstimulated adrenal cortex numerous thrombi may be formed leading thus to the degeneration of adrenocortical cells. Thus, the appearance of the "empty spaces" or "holes" in the gland is not connected with the holocrine secretion but with the regulation of the number of secretory cells in adrenal cortex by the thrombi-dependent mechanism.(ABSTRACT TRUNCATED AT 250 WORDS)     

Seasonal Adreno-Cortical Cycle of a Nocturnal Bird, Indian Spotted Owlet Athene brama: Biochemical and Morphological Observations

It is well reported that the environmental factors along with different endocrine stimulus play a crucial role in maintenance of adrenocortical activity in birds. This study is first to report a detailed seasonal activity cycle of adrenal cortex, particu-larly its secretory physiology in a tropical nocturnal bird, Indian spotted owlet Athene brama . The maximum cortical activity having highest glandular mass, glandular free cholesterol, esterified cholesterol profiles, and peak level of corticosterone in plasma coincided with the long day length, highest temperature and increasing amplitude of relative humidity and rainfall of the early summer month, May. Cortical activity declined to minimum level in August when the ecofactors also declined parallely and hence, the birds entered into partial hibernation. The cortical activity progressed slowly throughout the winter (September-March) to reach maximum level in May. Further, the electron microscopic observations of cortical cell morphology strongly supported the above seasonal activity status of the gland revealing a comparatively large number of mitochondria during May than August, along with lipid filled vacuoles during May but not in August. Besides, assessment of gonadal and pineal hormones in relation with seasonal activity of adrenal cortex presented a parallel relationship with gonad while completely inverse relationship with pineal. Therefore, the study concludes that the seasonal adrenocortical activity of this tropical nocturnal bird might be regulated by multiple factors, particularly by the environmental temperature, humidity/rainfall and photoperiod along with the internal factors at least by gonadal and pineal hormones.     

The connection of adrenal function to nutritional factors and milk productivity in ruminant animals

In this paper the literature and experimental data about ruminant's adrenal function in the connect with feeding level, ration structure and lactation are generalized and systematized. It is shown, that the adrenal secretion and either glucocorticoid, or katecholamine metabolism can be changed in the dependence on the alimentary factors. When the animals feeding is not adequate physiologically, increased cortisol secretion is necessary for supporting of glucose level in the normal value, what leads to increased loading to the adrenal cortex and is accompanied by redistribution of this hormone between plasma and erythrocytes. The hypothesis explaining the received results is advanced. The ability of the endocrine indexes utilization for the estimation of physiological adequately of rations is discussed. The role of adrenal hormones in the regulation of the mammary gland supplying with the milk precursors, and the mechanisms of these hormones action (either positive, or negative) to the organism lactation function are studying.     

Functional characteristics of the intraspinal spread of viscerosomatic activity.

The functional characteristics of the intraspinal spread of the dual-component viscerosomatic reflex response were studied in chloralose-anaesthetized cats. In the region of the direct inputs of splanchnic afferents into the spinal cord, the initial part of the early (propriospinal) component is evoked by afflux from the extraspinal pathway in the sympathetic chain and has the shortest latent period. At segment Th8 to Th12 level this was 5.2--8.1 msec; cranially and caudally from this level it was longer. Activity spreading from the adjacent segments via intraspinal longitudinal systems also participates in the origin and course of the early component of the efferent discharge. The rate of ascending intraspinal irradiation in the thoracic region was 3.2--12 m/sec (6.6 +/- 2.4 m/sec). The rate of the descending spread of propriospinal activity in the thoracic region via intraspinal pathways was 3.6--18.3 m/sec (12.5 +/- 4.5 m/sec); in the lumbar region it was significantly lower -- 2.9--19.3 m/sec (7 +/- 4.5 m/sec). The latent period of the later component varied from 20 to 30 msec and displayed a cranio-caudal increase in length. The rate of the descending spread of the later component in the thoracic and lumbar cord did not differ significantly (20 +/- 10 m/sec and 22 +/- 13 m/sec respectively). The continuous splanchnic discharge in the lumbosacral region is correlated to the different rate of the intraspinal spread of the early and the late response and to their overlapping.     

Absence of HDL cholesteryl ester uptake in mice via SR-BI impairs an adequate adrenal glucocorticoid-mediated stress response to fasting

Receptor-mediated cholesterol uptake has been suggested to play a role in maintaining the adrenal intracellular free cholesterol pool and the ability to produce hormones. Therefore, in the current study, we evaluated the importance of scavenger receptor class B type I (SR-BI)-mediated cholesteryl ester uptake from HDL for adrenal glucocorticoid hormone synthesis in vivo. No difference was observed in the plasma level of corticosterone between SR-BI-deficient and wild-type mice under ad libitum feeding conditions. Overnight fasting ( approximately 16 h) stimulated the plasma level of corticosterone by 2-fold in wild-type mice. In contrast, no effect of fasting on plasma corticosterone levels was observed in SR-BI-deficient mice, leading to a 44% lower plasma corticosterone level compared with their wild-type littermate controls. In parallel, an almost complete depletion of lipid stores in the adrenal cortex of fasted SR-BI-deficient mice was observed. Plasma adrenocorticotropic hormone levels were increased by 5-fold in fasted SR-BI-deficient mice. SR-BI deficiency induced marked changes in the hepatic expression of the glucocorticoid-responsive genes cholesterol 7alpha-hydroxylase, HMG-CoA synthase, apolipoprotein A-IV, corticosteroid binding globulin, interleukin-6, and tumor necrosis factor-alpha, which coincided with a 42% decreased plasma glucose level under fasting conditions. In conclusion, we show that the absence of adrenal HDL cholesteryl ester uptake in SR-BI-deficient mice impairs the adrenal glucocorticoid-mediated stress response to fasting as a result of adrenal glucocorticoid insufficiency and attenuated liver glucocorticoid receptor signaling, leading to hypoglycemia under fasting conditions.