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PubMed1988

Cross-talk between the immune and endocrine systems.

Significant advances have been made in the field of immunophysiology since Selye discovered that acute stressors reduce the size of lymphoid organs. It is known that a variety of hormones other than glucocorticoids affect functional activities of lymphoid cells and macrophages. This paper summarizes recent findings of the effects of glucocorticoids and other hormones on lymphoid cells of domestic animals. Glucocorticoid and beta-adrenergic receptors are up-regulated on activated lymphoid cells. Classic pituitary hormones are synthesized by lymphoid cells, and both growth hormone and prolactin appear to have distinct roles as immunomodulators. In addition, certain activities of lymphoid cells may be behaviorally conditioned. These findings support the hypothesis that changes in the endocrine system affect lymphoid cells. They also suggest that products of the immune system affect the endocrine system. These findings provide a firm functional basis for the possibility of cross-talk between these two physiological systems.

Animals↗

PubMed2002

The calcium endocrine system of adolescent rhesus monkeys and controls before and after spaceflight.

The calcium endocrine system of nonhuman primates can be influenced by chairing for safety and the weightless environment of spaceflight. The serum of two rhesus monkeys flown on the Bion 11 mission was assayed pre- and postflight for vitamin D metabolites, parathyroid hormone, calcitonin, parameters of calcium homeostasis, cortisol, and indexes of renal function. Results were compared with the same measures from five monkeys before and after chairing for a flight simulation study. Concentrations of 1,25-dihydroxyvitamin D were 72% lower after the flight than before, and more than after chairing on the ground (57%, P < 0.05). Decreases in parathyroid hormone did not reach significance. Calcitonin showed modest decreases postflight (P < 0.02). Overall, effects of spaceflight on the calcium endocrine system were similar to the effects of chairing on the ground, but were more pronounced. Reduced intestinal calcium absorption, losses in body weight, increases in cortisol, and higher postflight blood urea nitrogen were the changes in flight monkeys that distinguished them from the flight simulation study animals.

Aging↗

PubMed1992

Effects of 1-week head-down tilt bed rest on bone formation and the calcium endocrine system.

To understand the potential early responses of human bone and the calcium endocrine system to spaceflight, we studied 8 healthy men, aged 35-44 years before, during, and after bed rest in a -6 degrees head-down tilt model for microgravity. Based on a novel single-dose labeling schedule, average rates of bone formation in the iliac crest were reduced in 6, unchanged in 1, and increased in 1 following the bed rest period. The decrease was greatest for subjects whose daily walking miles were highest (r = -0.762, p less than 0.05, n = 7). Before a measurable increase in ionized serum calcium the sixth bed rest day, there was increased excretion of urinary calcium and sodium, evident the first 2 bed-rest days and parallel for the entire week (r = 0.92, p less than 0.001). Reduced excretion of phosphorus and 3', 5' cyclic adenosine monophosphate on the first and second bed rest days was followed by an increase in serum phosphorus by the sixth bed rest day. Depressed serum concentrations of parathyroid hormone and 1,25-dihydroxyvitamin D were manifest by the sixth and seventh bed rest days. The similarity of the response of bone and the calcium endocrine system of healthy men after only 7 days to results of longer term bed rest studies emphasizes the responsiveness of the adult human skeleton to biomechanical stimuli induced by changes in activity and/or position.

Adult↗

PubMed2006

The endocrine system in treated patients with classical galactosemia.

Endocrine abnormalities in classical galactosemia, female hypergonadotropic hypogonadism and low thyroxin in neonates, have been reported. Galactosemia is a secondary glycosylation disorder and hypoglycosylation of glycoproteins has a role in this dysfunction. Hypoglycosylation, improves but does not completely disappear with dietary treatment. Our aim was to evaluate the endocrine system in treated patients (n = 37, 25 females, 12 males, age 5-19 years). Endocrine determinations were compared to age and gender matched reference ranges. Sample t-test (to test differences with reference population) and linear regression analysis between hGH (growth hormone), IGF-1 (insulin-like growth factor), IGFBP-3 (insulin growth factor binding protein), FSH (follicle stimulating hormone), LH (luteinizing hormone) and GALT activity, and soy intake, was carried out. Mean IGF-1 Z-score was -0.98 +/- 0.84 (range -2.59 to 1.21) (P < 0.001) in females and 0.03 +/- 0.55 (range -1.0 to 0.89) (P = 0.84) in males. Mean IGFBP-3 Z-score was -0.98 +/- 1.3 (range -3.0 to 2.0) (P < 0.001) in females and 0.26 +/- 0.93 (range -0.94 to 2.0) (P = 0.35) in males. IGF-1 and IGFBP-3 were positively correlated (P < 0.001). IGF-1 or IGFBP-3 Z-scores and age, hGH, estradiol, GALT activity or soy intake were not correlated. FSH was elevated in females, other axes were normal. Besides the hypergonadotropic hypogonadism in females, IGF-1 and IGFBP-3 are in the low to normal ranges in girls. Hypoglycosylation in galactosemia is diet dependent and could worsen when galactose intake increases either because of poor compliance or diet liberalization.

Adolescent↗

PubMed1983

The vitamin D endocrine system, calcium metabolism, and osteoporosis.

Although the nutritional aspects related to bone development and subsequent bone loss have been appreciated for many years, they are now being reemphasized in view of current information concerning the vitamin D endocrine system, the development of new assay procedures and more sensitive radiologic techniques to assess changes in bone mass, and the realization that clinical problems related to bone loss will increase as individuals live longer. The vitamin D endocrine system is complex, involving the skin, liver, and kidney for synthesis of the vitamin D metabolites and, primarily, the intestine and bone for biologic expression. Numerous factors and disorders affecting the skin, gastrointestinal tract, and kidney will adversely affect vitamin D metabolism. Vitamin D deficiency is common in elderly individuals, especially those who are chronically ill, house-bound, and poorly nourished. Subclinical vitamin D deficiency and osteomalacia may also be complicating problems in elderly patients with osteoporosis and hip fractures. At present the role of the vitamin D endocrine system in the pathogenesis and treatment of osteoporosis is unclear. There is little evidence that vitamin D or its metabolites are helpful in osteoporosis, except perhaps to heal osteomalacia which may be present. It is hoped that encouraging results will follow the use of more potent vitamin D metabolites, either alone or in combination with other agents. Calcium homeostasis is affected by numerous dietary factors (including protein, phosphorus, fiber, and lactose) and drugs (including alcohol, diuretics, and antacids), and calcium absorption in the intestine and the ability to adapt to low-calcium diets will decrease with advancing age. There are conflicting reports concerning the relation between low-calcium intake and osteoporosis, and about the role of calcium intake in the development and then maintenance of bone mass. There is little doubt that many older individuals ingest less calcium than is recommended, especially at a time when even more may be required to maintain bone mass. Several studies show that calcium supplementation producing a total calcium intake of 1,200-1,500 mg/day can slow the rate of bone loss. When the high doses of calcium are given along with vitamin D, periodic monitoring of blood and urine calcium is necessary to avoid hypercalcemia and hypercalciuria.

Aged↗

PubMed2004

Ghrelin expression and actions: a novel peptide for an old cell type of the diffuse endocrine system.

Ghrelin is a gastric peptide involved in food intake control and growth hormone release. Its cell localization has been defined in distinct ghrelin cells of the gastric mucosa in humans and other mammals. Ghrelin production was also described in a number of other sites of the diffuse endocrine system, including the pituitary, thyroid, lung, pancreas, adrenal gland, and intestine. In addition, ghrelin cells were identified early during fetal life and in the placenta and gonads. Finally, endocrine growths and tumors of the diffuse endocrine system may present ghrelin-producing cells, and in a few cases high levels of circulating ghrelin were reported. Besides its well-defined orexigenic role, ghrelin is likely to exert a local paracrine role similar to other brain-gut axis hormones. This review aims to summarize recent data on ghrelin cell distribution in the diffuse endocrine system and discuss local and general ghrelin function during development, adulthood, and endocrine tumor development.

Amino Acid Sequence↗

PubMed1997

The relationship between the immune and endocrine systems.

Increasing evidence links the immune and endocrine systems. Cytokines produced by activated immune and immune accessory cells can affect, positively or negatively, the secretion of hormones from the hypothalamic-pituitary-adrenal or hypothalamic-pituitary-ovarian axes. On the other hand, adrenal and ovarian hormones affect the secretion of cytokines by cells of the immune system. The interaction also occurs at a local level in paracrine or autocrine fashion. Cytokines produced by resident ovarian macrophages or ovarian cells can affect the follicle and the corpus luteum and, consequently, ovarian steroidogenesis at both phases of the menstrual cycle. Conversely, the ovarian steroids influence, positively or negatively, the secretion of cytokines from both the resident macrophages and local endocrine cells.

Cytokines↗

PubMed2006

Further EST analysis of endocrine genes that are preferentially expressed in the neural complex of Ciona intestinalis: receptor and enzyme genes associated with endocrine system in the neural complex.

Identification of orthologs of vertebrate neuropeptides and hypothalamic hormones in the neural complex of ascidians suggests integral roles of the ascidian neural complex in the endocrine system. In the present study, we investigated endocrine-related genes expressed in the neural complex of Ciona intestinalis. Comprehensive analyses of 3'-end sequences of the neural complex cDNAs placed 10,029 clones into 4051 independent clusters or genes, 1524 of them being expressed preferentially in this organ. Comparison of the 1524 genes with the human proteome databank demonstrated that 476 matched previously identified human proteins with distinct functions. Further analyses of sequence similarity of the 476 genes demonstrated that 21 genes are candidates for those involved in the endocrine system. Although we cannot detect hormone or peptide candidates, we found 21 genes such as receptors for peptide ligands, receptor-modulating proteins, and processing enzymes. We then characterized the Ciona prohormone convertase 2 (Ci-PC2) and carboxypeptidase E (Ci-CPE), which are associated with endoproteolytic processing of peptide hormone precursors. Furthermore, genes encoding these transcripts are expressed specifically in the neural complex of young adult ascidians. These data provide the molecular basis for further functional studies of the endocrine role of the neural complex of ascidians.

Amino Acid Sequence↗

PubMed1992

Comparative histological overview of the chemical coding of the pulmonary neuroepithelial endocrine system in health and disease.

Pulmonary neuroepithelial endocrine cells have been shown to contain serotonin-immunoreactivity in almost every species studied. Regulatory peptides, of which at least ten have been reported so far, were mostly only demonstrated in a number of the investigated species or in a subpopulation of neuroepithelial endocrine cells. Calcitonin gene-related peptide, calcitonin, bombesin/gastrin-releasing peptide, enkephalin, somatostatin, substance P, cholecystokinin and polypeptide YY were found in normal lung tissues, whereas ACTH and several other bioactive substances should be regarded as ectopic. The human pulmonary neuroepithelial endocrine system seems to harbour the largest spectrum of bioactive mediators. The distribution patterns of bioactive substances in various subpopulations of solitary neuroepithelial endocrine cells or neuroepithelial bodies and in different cells of a single neuroepithelial body reveal a great complexity. Therefore, further research is needed to elucidate the chemical coding of this system.

Animals↗

PubMed1984

Increased deaths due to endocrine system diseases and allergies among mothers of dizygotic twins.

To test the hypothesis that mothers of DZ twins, who seem to represent a separate population from mothers of singletons in terms of levels of pituitary gonadotropins, height and weight, and reproductive and menstrual characteristics, have different patterns of disease and mortality, causes of non-cancer deaths were examined. Study subjects were 3,982 mothers of unlike-sexed (DZ) twins and other polyzygous multiple births, and a matched comparison group of 3,982 mothers of singletons only. A significantly increased risk of death due to diseases in ICD Group III, Allergic Endocrine System, Metabolic and Nutritional Diseases, was found among mothers of DZ twins (relative risk (RR) = 2.4, exact two-tail P = 0.024, exact 95% confidence limits 1.11 to 5.62). Of the 24 deaths among mothers of DZ twins, 18 were due to diabetes, 2 to diseases of the adrenal glands, 1 to a thyroid gland and, 3 to asthma. Of the ten deaths in the comparison group, nine were due to diabetes and one to asthma. Excluding the asthmas, the RR for endocrine system diseases is 2.33, exact two-tail P = 0.042, exact 95% CL 1.02 to 5.79. These observations are consistent with evidence in the literature which shows an association between endocrine system diseases and twinning, and between gonadotropic hormones and diabetes.

Connecticut↗

PubMed1996

[Cytokine therapy and the endocrine system: is it necessary to monitor more than the thyroid gland?].

UNLABELLED: Cytokines and Endocrine System: Is it Meaningful to Monitor More than the Thyroid Gland? AIM: It was the aim of this study to evaluate the occurrence, the degree, and clinical relevance of immunological phenomena in endocrine and non-endocrine organs as seen under therapy with interferon-alpha (IFN-alpha) and/or interleukin-2 (Il-2). PATIENTS AND METHODS: In 61 patients (age: 50.2 +/- 12.8 years) receiving cytokines as treatment for hepatological or hemato-oncological diseases, parameters of the thyroid gland, the gonadal system, the adrenal gland the pituitary gland, parameters of water and electrolyte-balance, and of bone metabolism were measured. All patients were treated with interferon in a mean dosage of 15.3 +/- 10.5 mio U subcutaneously per week. Additionally, 15 patients were treated with interleukin-2 (36.5 +/- 22.3 mio U subcutaneously per week). Among other assays, patients "sera were screened for the existance of autoantibodies against 30 different antigenic substrates using an indirect immunofluorescence technique (IIF). RESULTS: Pts, treated with IFN-alpha and IL-2 (n = 13) showed a significant induction of thyroid antibodies against thyroglobulin (anti-TG): 61 +/- 82 U/ml vs. 1000 +/- 2352 U/ml (p < 0.05) and against thyroid-peroxidase (anti-TPO): 162 +/- 538 vs. 468 +/- 1071 U/ml (p < 0.05). In pts, only treated with IFN-alpha (n = 26), the increase of anti-TG from 69 +/- 97 to 134 +/- 178 U/ml and of anti-TPO from 20 +/- 21 to 21 +/- 19 U/ml was insignificant. Patients with a combined treatment of IFN-alpha and Il-2 were mainly affected: 2 patients developed hypo- and 5 hyperthyroidism. Thus, regular controls of thyroid function during the entire duration of therapy is justified. We were unable to show any influence of the duration of treatment or dosage of cytokines on the endocrine and non-endocrine parameters investigated. In addition, 8 different AAB (against smooth/striated muscles, parietal cells, nuclear parts, myelin, keratin, endothel, and neuroendothel) were detected by IIF which did not change under therapy. Two patients newly developed AAB during therapy, however none of them suffered from clinical symptoms. AAB against endocrine organs other than the thyroid gland were not detected. No other endocrine system showed alterations of its function. CONCLUSION: Based on the data of this study we conclude that the thyroid gland should be regularly monitored for immunological and functional changes during cytokine therapy. The results do not support a general recommendation for a routine screening of other, non-thyroidal endocrine systems for autoimmune phenomena and alterations of function in each patient.

Adult↗

PubMed1991

[Interactions of circadian biorhythms of the immune and endocrine systems in mice].

The original and reported data on circadian biorhythms of the immune and endocrine systems are summarized. A hypothetic scheme of the circadian organization of lymphocyte redistribution, proliferation and metabolism in mice is provided, interactions of circadian biorhythms and circadian fluctuations of functional activity of the immune system are demonstrated. It has been shown that circadian rhythms of the immunologic parameters are dependent on the regulative influence of hypophyseal hormones, glucocorticoids, and thymic endocrine factors. Interactions of the immune and endocrine systems in different phases of the circadian cycle have been specified.

Animals↗

PubMed2000

Relationship between fatty acids and the endocrine system.

Significant interactions exist between fatty acids and the endocrine system. Hormones affect the metabolism of fatty acids and the fatty acid composition of tissue lipids. The principal hormones involved in lipid metabolism are insulin, glucagon, catecholamines, cortisol and growth hormone. The concentrations of these hormones are altered in chronic degenerative conditions such as diabetes and cardiovascular disease, which in turn lead to alterations in tissue lipids. Lipogenesis and lipolysis, which modulate fatty acid concentrations in plasma and tissues, are under hormonal control. Neuropeptides are involved in lipid metabolism in brain and other tissues. Polyunsaturated fatty acids (PUFA) are also precursors for eicosanoids including prostaglandins, leukotrienes, and thromboxanes, which have hormone-like activities. Fatty acids in turn alter both hormone and neuropeptide concentrations and their receptors. Saturated and trans fatty acids (TFA) decrease insulin concentration leading to insulin resistance. In contrast, PUFA increase plasma insulin concentration and decrease insulin resistance. In humans, omega-3 PUFA alter the levels of opioid peptides in plasma.

Animals↗

PubMed1952

Functioning tumors of the endocrine system.

Explore the source record for details and available documents.

Endocrine Gland Neoplasms↗

PubMed1990

The avian as an animal model for the study of the vitamin D endocrine system.

This paper presents a summary of experimental studies which utilized the White Leghorn cockerel, Gallus domesticus, as a suitable avian model for a detailed analysis of the mode of action of the seco-steroid vitamin D. It is now apparent that there exists a complex endocrine system which coordinates the metabolism of the parent vitamin D into a family of over 30 metabolites; the principal metabolites are 1,25(OH)2D3 and 24R,25(OH)2D3, which together orchestrate the spectrum of biological responses attributable to vitamin D. Key advances in elucidation of the scope of vitamin D endocrine system include the tissue distribution of both its steroid receptor and its gene-induced product, a 28,000 dalton calcium binding protein, termed calbindin-D28k. To date no less than 23 tissues have been found to have specific 1,25(OH)2D3 receptors; of these at least 10 were identified in avian studies. Similarly, nine avian tissues have been found to express the vitamin D-induced calcium binding protein, calbindin-D28k. These observations collectively demonstrate both the broad scope of the vitamin D endocrine system and the appropriateness of using avians as valid models for vitamin D endocrine research which has applicability and validity for mammals, including man.

Animals↗

PubMed1987

Studies on the vitamin D endocrine system in the avian.

This report summarizes the current understanding of the mode of action of vitamin D and emphasizes the contributions to this system that have been based on results obtained in avian species. A complex endocrine system coordinates the metabolism of vitamin D into 1,25-dihydroxycholecalciferol[1,25(OH)2D3] and 24R,25-dihydroxycholecalciferol[24R,25)OH)2D3] and 28 other metabolites; of these 16 were originally isolated and chemically characterized from avian systems. Key advances in understanding the mode of action of the seco-steroid 1,25(OH)2D3 and the scope of its action have been made by studying the tissue distribution of both its receptor and its gene-induced product, a 28,000-dalton calcium-binding protein termed calbindin-D28K. To date no less than 23 tissues have been found to have specific 1,25(OH)2D3 receptors; of these 10 were identified in avian studies. Similarly, nine tissues express the vitamin D-induced calbindin; seven have been reported in avian tissues. The second dihydroxylated metabolite, 24R,25(OH)2D3, has been reported to be capable of inducing a variety of specific biological effects, some when the steroid is administered alone and some in the presence of its companion dihydroxylated metabolite 1,25(OH)2D3. There is emerging evidence for the existence of specific receptors for 24R,25(OH)2D3, particularly in chondrocytes and parathyroid glands (both studied in avian systems). These observations collectively demonstrate the broad scope of the vitamin D endocrine system.

Animals↗

PubMed1993

Territorial aggressiveness and its relation to the endocrine system in the pied flycatcher.

Behavioral and endocrine responses were studied following simulated territorial intrusions performed at two different stages in the breeding cycle (pre-nest-building and nestling period) of the pied flycatcher (Ficedula hypoleuca). Only 45% of the unpaired territorial males from the pre-nest-building period defended their territories by attacking the decoy. After the experimental intrusion unpaired males attacking the decoy had significantly higher plasma testosterone levels than nonattacking unpaired males. Plasma corticosterone levels were significantly higher in both attacking and nonattacking unpaired males than in control males. There were no differences in body size between attacking and nonattacking males. The attacking paired males and paired control males, however, had significantly lower fat depots than other males. The endocrine system of the male pied flycatcher responded within 1 day to the settlement of a female in the territory in that plasma testosterone levels of paired control males were significantly higher than those in unpaired territorial control males. The proportions of attacking males increased significantly (up to 80%) once a female had settled. Unlike in unpaired territorial males, testosterone levels in paired males that attacked the decoy were similar to those in non-attacking males and to those in paired control males after a simulated territorial intrusion. Data suggest that the high testosterone levels are related to territorial aggressiveness and not to sexually related events such as mate-guarding or singing. Forty-five percent of the males from the nestling period did attack the decoy. Despite the strong behavioral response these attacks had no effects on plasma testosterone or corticosterone levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Aggression↗

PubMed1999

Presence and distribution of neuroendocrine cells in the gastroenteropancreatic endocrine system of fallow deer foetuses.

The gastroenteropancreatic endocrine system was studied in 11- and 17-week-old fallow deer foetuses using an immunocytochemical technique. In the gastrointestinal tract, gastrin-, serotonin-, somatostatin- and cholecystokinin-containing cells were found: their frequency and distribution were also determined. Anti-glucagon and anti-insulin antibodies did not stain any cells along the gut. In the pancreas, somatostatin-, pancreatic polypeptide-, insulin- and glucagon-immunoreactive cells were detected. The different distribution and number of neuroendocrine cells, in the two investigated stages of foetal life, are discussed. Data obtained in this study were compared with those published in a previous study on the gastrointestinal system of the adult fallow deer.

Animals↗