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At least 145 records · Page 8Linked to original sources

Study of sodium bromide in human volunteers, with special emphasis on the endocrine system.

1 Bromide, 1 mg kg-1 daily, was administered to 21 healthy volunteers (11 females not using oral contraceptives and not pregnant and 10 males, during 8 weeks or 2 full cycles to determine whether ingestion of a dose equal to the acceptable daily intake might induce effects. Special attention was paid to the endocrine system because endocrine changes were predominant in rats receiving sodium bromide (NaBr) in their diets. 2 There was no difference between the results of a full medical history and physical examination at the start and at the end of the experiment. 3 The results from the measured haematological, biochemical and urine analyses did not change during the experiment. 4 In females the plasma bromide concentration rose from 0.08 +/- 0.01 mmol 1(-1) to 0.97 +/- 0.18 mmol 1(-1) and in males from 0.08 +/- 0.01 mmol 1(-1) to 0.83 +/- 0.09 mmol 1(-1) (mean +/- s.d.). 5 No changes were observed in the serum concentrations of thyroxine, free thyroxine, thyroxin binding globulin, triiodothyronine, cortisol, testosterone, estradiol and progesterone. Also no changes were observed in the serum concentrations of thyroid stimulating hormone (TSH), prolactin, luteinizing hormone (LH) and follicle stimulating hormone (FSH) before and after the administration of thyroid stimulating hormone releasing hormone (TRH) and luteinizing hormone releasing hormone (LHRH).

Adult↗

Identification of ecdysis-triggering hormone from an epitracheal endocrine system.

Developing insects repeatedly shed their cuticle by means of a stereotyped behavior called ecdysis, thought to be initiated by the brain peptide eclosion hormone. Here an ecdysis-triggering hormone, Mas-ETH, is described from the tobacco hornworm Manduca sexta. Mas-ETH contains 26 amino acids and is produced by a segmentally distributed endocrine system of epitracheal glands (EGs). The EGs undergo a marked reduction in volume, appearance, and immunohistochemical staining during ecdysis, at which time Mas-ETH is found in the hemolymph. Injection of EGs extract or synthetic Mas-ETH into pharate larvae, pupae, or adults initiates preecdysis within 2 to 10 minutes, followed by ecdysis. Sensitivity to injected Mas-ETH appears much earlier before ecdysis and occurs with shorter latency than that reported for eclosion hormone. The isolated central nervous system responds to Mas-ETH, but not to eclosion hormone, with patterned motor bursting corresponding to in vivo preecdysis and ecdysis. Mas-ETH may be an immediate blood-borne trigger for ecdysis through a direct action on the nervous system.

Amino Acid Sequence↗

Evidence for alteration of the vitamin D-endocrine system in blacks.

As compared with values in white subjects, bone mass is known to be increased and urinary calcium to be diminished in black individuals. To evaluate the possibility that these changes are associated with alterations in the vitamin D-endocrine system, an investigation was performed in 12 black subjects, 7 men and 5 women, and 14 white subjects, 8 men and 6 women, ranging in age from 20 to 35 yr. All of them were hospitalized on a metabolic ward and were given a constant daily diet containing 400 mg of calcium, 900 mg of phosphorus, and 110 meq of sodium. Whereas mean serum calcium, ionized calcium, and phosphate were the same in the two groups, mean serum immunoreactive parathyroid hormone (350 +/- 34 vs. 225 +/- 26 pg/ml, P less than 0.01) and mean serum 1,25-dihydroxyvitamin D (1,25(OH)2D) (41 +/- 3 vs. 29 +/- 2 pg/ml, P less than 0.01) were significantly higher, and mean serum 25-hydroxy-vitamin D (25-OHD) was significantly lower in the blacks than in the whites (6 +/- 1 vs. 20 +/- 2 ng/ml, P less than 0.001). Mean urinary sodium and 24-h creatinine clearance were the same in the two groups, whereas mean urinary calcium was significantly lower (101 +/- 14 vs. 166 +/- 13 mg/d, P less than 0.01) and mean urinary cyclic AMP was significantly higher (3.11 +/- 0.47 vs. 1.84 +/- 0.25 nM/dl glomerular filtrate, P less than 0.01) in the blacks. Further, the blacks excreted an intravenous calcium load, 15 mg/kg body weight, as efficiently as the whites (49 +/- 3 vs. 53 +/- 3%, NS). Mean serum Gla protein was lower in blacks than in whites (14 +/- 2 vs. 24 +/- 3 ng/ml, P less than 0.02), and increased significantly in both groups in response to 1,25(OH)2D3, 4 micrograms/d for 4 d. There was a blunted response of urinary calcium to 1,25(OH)2D3 in the blacks, and mean serum calcium did not change. The results indicate that alteration of the vitamin D-endocrine system with enhanced renal tubular reabsorption of calcium and increased circulating 1,25(OH)2D as a result of secondary hyperparathyroidism may contribute to the increased bone mass in blacks. Their low serum 25-OHD is attributed to diminished synthesis of vitamin D in the skin because of increased pigment.

Adult↗

The neuro-endocrine complex in the gastro-entero-pancreatic endocrine system.

The pancreatic islet is one of the well-studied endocrine tissues in regard to innervation. This neuro-insular complex has been known since the 1920's. The direct contact of the nervous element to the gastro-enteric endocrine cells has recently been reported in the proventricular mucosa of the finch. Here, the majority of the endocrine cells lie in the lamina propria and form a neuro-endocrine complex with unmyelinated nerve fibers. A similar neuro-endocrine complex was also reported in the rat stomach and in the duodenum of the human fetus. The occurrence of the neuro-endocrine complexes in the gastro-entero-pancreatic endocrine system might provide supportive data to the neuro-ectodermal theory on the origin of the endocrine cells proposed by Professors A. G. E. PEARSE and T. FUJITA.

Animals↗

Development of cholecystokinin and pancreatic polypeptide endocrine systems during the larval stage of Japanese flounder, Paralichthys olivaceus.

To understand the developmental process of the endocrine system, which controls the pancreatic exocrine function in Japanese flounder, Paralichthys olivaceus, the expression patterns of cholecystokinin (CCK) and pancreatic polypeptide (PP) during the larval stage were analyzed by immunohistochemistry and in situ hybridization. Expression of CCK in the intestinal epithelia started at 2 days posthatching (dph), 1 day prior to the first feeding. Endocrine pancreatic cells containing insulin were present in the pancreas primodium at hatching, and these endocrine cells formed an islet at 3 dph and developed into the principle islet neighboring gallbladder at 20 dph. However, PP cells were not contained in the principle islet even after metamorphosis. PP cells were contained in the accessory islets differentiated around the proximal part of the pyloric appendages at 30 dph (early metamorphosis stage). Therefore, we infer that the stimulative regulation of pancreatic enzyme secretion by CCK starts to function at the first feeding, whereas the restrictive regulation by PP develops about 1 month later in flounder larvae. In addition, we observed that CCK immunoreactive cells appeared in the accessory islets at 30 dph, similar to PP cells, even though CCK mRNA expression could not be detected in cells from the islets. This indicates the possibility that a peptide that is cross-reacted with the CCK antibody, i.e., gastrin, is synthesized in the flounder islets.

Animals↗

Quantitative histochemical investigation of rat salivary gland at different age stages of involution of the endocrine system.

A complex quantitative histochemical investigation of the submandibular salivary glands in female albino rats at different age periods (4-5 month, 12 to 14 month- and 20 to 25 month-old) revealed some structural and functional changes during the oestrus cycle. The animals were grouped according to the age changes of the endocrine system. The salivary glands were sensitive to hormonal balance changes at all age periods but their metabolic interrelations varied. The functional changes in the salivary glands of young rats were accompanied by synchronous changes in the indices of energy, synthesis and transport metabolism. The gradual increase of disintegration of the endocrine system resulted in the uncoupling between the indices of the parenchyma and the microcirculation, as well as between nucleo-cytoplasmic relationships and intracellular transport processes in the salivary glands. That was a condition under which the impairment of cellularly excretory processes occurred (secretory stasis). The intercalated ducts and the striated tubules were especially sensitive to hormonal balance fluctuations which is consistent with the hypothesis of the endocrine nature of their function.

Aging↗

The diffuse endocrine system and derived tumours. Histological and histochemical characteristics.

The Diffuse Endocrine System, to which the so-called APUD (Amine Precursor Uptake and Decarboxylation) cells do belong, gives rise to a group of tumours which may or not secrete amines and/or polypeptide hormones: carcinoids (argentaffinomas, argentaffin or Kultschitzky cell carcinomas). Foregut carcinoids are predominantly of B type (trabecular), argyrophilic, or non-reactive (in about 70% of cases) to silver impregnation. Midgut tumours are generally of A type (insular); more than 80% of them are argentaffinic. Hindgut derived carcinoids are primarily of mixed type; nearly 70% are non-reactive to silver stains. From a cytological standpoint all types may be build up of either small-round, spindle-shaped, polyhedral or cuboidal cells. From a functional point-of-view, the cells are either clear and immature, non-reducing or exhausted. Accordingly, the diagnosis cannot be based alone on silver impregnation or other histochemical methods.

APUD Cells↗

Light, endocrine systems and cancer--a meeting report.

The International Symposium "Light, Endocrine Systems and Cancer" was held on May 2-3 at Cologne University, Germany. The symposium was organized by Professor Claus Piekarski and Dr. Thomas C. Erren, Institute and Polyclinic for Occupational and Social Medicine. The main goal of the symposium was to evaluate the epidemiological and experimental data on the effect of the exposure to light-at-night on cancer risk and to indicate the main directions of future research in the field. The symposium covered also the mechanisms and epidemiology of skin cancer which, however, are not included in the present summary.

Animals↗

Cytochemical demonstration of somatostatin 28-(1-14)-like immunoreactivity in the rat hypothalamus and gastro-entero-pancreatic endocrine system.

Somatostatin-28 (SS 28) is a NH2-terminally extended form of somatostatin-14 (SS 14). Using an antiserum whose antigenic determinant is contained in segment 1-14 of SS 28, the cellular localization of a SS 28-(1-14)-like immunoreactivity was examined in the hypothalamus and gastro-enteropancreatic endocrine system of the rat. Immunoreactivity for SS 28-(1-14) was recognized in the SS 14-immunoreactive nerve cells of the hypothalamus and their axons terminating in the median eminence. Electron microscopic immunocytochemistry revealed that SS 28-(1-14)-like immunoreactivity in the median eminence was localized in the secretory granules of a type of nerve terminal. The immunoreactive cells in the gastro-enteropancreatic endocrine system also corresponded to the SS 14-immunoreactive D cells. Only in the pyloric antrum, however, did SS 14-immunoreactive D cells show no or very weak reactivity to the anti-SS 28-(1-14) serum. The wide distribution of SS 28-(1-14)-like immunoreactivity in the same cellular elements as those containing SS 14 supports the view that SS 28 is a precursor of SS 14.

Animals↗

Influence of allogeneic bone marrow transplantation on the endocrine system in children.

With increasing survival rates of children grafted for different malignancies concerns about the longterm side effects of this treatment are growing. Therefore, investigations on the function of endocrine systems were conducted in a total 28 patients grafted for various reasons: ALL (N = 18), AML (N = 1), SAA (N = 3), CML(N = 4), neuroblastoma (N = 2). The results can be summarized as follows: 1. The extent of hormonal derangements is primarily dependent on the extent of irradiation prior to BMT. Integrity of hormonal systems was found in cases without irradiation (SAA) or if TBI did not exceed 3 Gy. 2. Primary hypogonadism was present in 18 patients. 3. Primary hypothyroidism was present in 2 patients. 4. Growth impairment was observed in 8 patients. In four of these cases growth hormone deficiency was the cause. In four other cases with graft-versus-host-disease and hepatic involvement SmC/IGF I levels were severely diminished. The data suggest that in most cases BMT itself has relatively few negative effects on the endocrine regulatory system. However, more detailed investigations before and after BMT will be needed to further validate these observations.

Anemia, Aplastic↗