Experimental and clinical endocrinology最新文献

{"title":"Regulation of interrenal secretion in the axolotl, Ambystoma mexicanum.","authors":"O P Gupta,&nbsp;W Hanke","doi":"10.1055/s-0029-1211295","DOIUrl":"https://doi.org/10.1055/s-0029-1211295","url":null,"abstract":"<p><p>The regulation of corticosteroid secretion of the adrenal cortex (interrenal tissue) of axolotl (Ambystoma mexicanum) was studied using in vitro preparations of kidney containing interrenal tissue. Normally, 0.3-0.65 ng/5 min corticosterone and 0.15-0.3 ng/5 min aldosterone were released from the tissue. Regulatory peptides were effective in the following range: ACTH = arginine vasotocin > urotensin II > angiotensin II. They stimulate an elevation of corticosterone (plus 0.2-1 ng/5 min) and of aldosterone (plus 0.05-0.15 ng/5 min). The three primary effector systems leading to second messengers, adenylate cyclase (forming cAMP), phospholipase C (forming InsP3 + DAG), and phospholipase A2 (liberating arachidonic acid) are involved in stimulation of biosynthesis. It can be suggested that the second messengers stimulate the biosynthesis at the level of the steps between pregnenolone and corticosterone ('3 beta-hydroxysteroid-dehydrogenase etc.), because the release of corticosterone is more stimulated than aldosterone. This is different than the regulation of anuran interrenal tissue. Ca++ ions are involved in corticosterone secretion. Verapamil inhibits immediately the secretion of corticosteroids and elevation of external Ca++ stimulates the release. It is suggested that Ca++ mediates the secretion process itself. Metamorphosis does not change the response of the interrenal gland compared with the neotenic animal.</p>","PeriodicalId":12104,"journal":{"name":"Experimental and clinical endocrinology","volume":"102 4","pages":"299-306"},"PeriodicalIF":0.0,"publicationDate":"1994-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1055/s-0029-1211295","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"18812575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular cloning of a cDNA encoding for the GLP-1 receptor expressed in rat lung.","authors":"B Lankat-Buttgereit,&nbsp;R Göke,&nbsp;H C Fehmann,&nbsp;G Richter,&nbsp;B Göke","doi":"10.1055/s-0029-1211301","DOIUrl":"https://doi.org/10.1055/s-0029-1211301","url":null,"abstract":"Recent data revealed the existence, localization and possible function of specific receptors for glucagon-like peptide 1 (7-36) amide (GLP-1) in rat lung. This receptor has different biochemical features than the GLP-1 receptor in endocrine pancreas. Therefore, we aimed to clone the lung receptor cDNA in order to analyze whether biochemical and functional diversity of the GLP-1 receptors in lung and pancreas is based upon genetic differences. A cDNA library from rat lung in a lambda gt11 vector was screened with a cDNA probe coding for the rat pancreas GLP-1 receptor. Thereby, we found a lung GLP-1 receptor cDNA which shows nearly complete homology to the pancreatic beta-cell receptor cDNA. Only one base exchange occurred at base 1 of a codon at position 977 resulting in a change of valine residue for isoleucine at position 323 of the amino acid sequence within the fifth transmembrane region. Northern blot hybridization identified transcripts at 2.7, 3.4, and 3.6 Kb. Expression of the recombinant lung GLP-1 receptor cDNA in CHO cells displayed a pharmacological profile similar to that seen with cells expressing the beta-cell derived cDNA. Therefore, we conclude that tissue-specificity for GLP-1 receptors is based upon posttranslational modifications of the receptor protein (for example glycosilation) or alternative splicing of primary transcripts and not on variations within the coding sequence of the receptor gene.","PeriodicalId":12104,"journal":{"name":"Experimental and clinical endocrinology","volume":"102 4","pages":"341-7"},"PeriodicalIF":0.0,"publicationDate":"1994-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1055/s-0029-1211301","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"18815602","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of estrone hydroxylase activities in porcine endometrial cells.","authors":"J Adamski,&nbsp;E Hohls,&nbsp;P W Jungblut","doi":"10.1055/s-0029-1211309","DOIUrl":"https://doi.org/10.1055/s-0029-1211309","url":null,"abstract":"<p><p>The oxidation of estradiol to estrone in porcine endometrial cells is succeeded by hydroxylation at either 6 alpha- or 7 alpha-. The products are devoid of receptor affinity. Their formation is inhibited by cytochrome P450 blockers like ketoconazol but not by chloroquine and analogues. The hydroxylation at 6 alpha- proceeds with KM = 1.9 x 10(-7) M, that at 7 alpha- with KM = 3.6 x 10(-7) M. The respective values for the cytochrome P450-reductase cosubstrate NADPH are 1.7 x 10(-5) M and 1.9 x 10(-5) M. The kinetic parameters of the enzymes are compatible with a metabolic sequence: estradiol-->estrone--> 6 alpha/17 alpha-estrone.</p>","PeriodicalId":12104,"journal":{"name":"Experimental and clinical endocrinology","volume":"102 5","pages":"388-93"},"PeriodicalIF":0.0,"publicationDate":"1994-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1055/s-0029-1211309","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"18867046","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thyroid volume and urinary iodine in school children and adolescents in Slovakia after 40 years of iodine prophylaxis.","authors":"P Langer,&nbsp;M Tajtáková,&nbsp;J Podoba,&nbsp;L Kost'álová,&nbsp;R Gutekunst","doi":"10.1055/s-0029-1211310","DOIUrl":"https://doi.org/10.1055/s-0029-1211310","url":null,"abstract":"<p><p>The thyroid volume (by ultrasonographic volumetry) was estimated in 4,254 schoolchildren and adolescents 6-18 years of age from 12 districts of Slovakia and urinary iodine (by dry alkaline ashing followed by spectrophotometry) in 1,174 spot urine samples. No differences in thyroid volume or in iodine excretion between individual districts were found. Similarly, no differences in thyroid volume between sexes were found up to the age of 14 years, however, thereafter, such volumes were considerably higher in boys. When comparing our cummulated data with those reported by others for a population with optimal iodine intake, it was found: 1. the medians for most of the examined age groups were slightly higher, 2. the percentage of values which were higher than 97 percentiles of normal population was 3.01 for the age of 6-14 years, while that for the age of 15-18 years was 9.04. Only 35.9% of all values of urinary iodine were in the optimal range (i.e. 10-20 mud/dl), while 56.1 were less than 10 micrograms/dl and 15.9% less than 5 micrograms/dl, the remaining 8.0% over 20 micrograms/dl. In spite of long-term iodine prophylaxis (since 1949), the intake of iodine apparently is still not satisfactory, since a considerable amount of individuals appeared to be iodine deficient on the day of examination. Iodine intake, however, may be marginally sufficient up to the age of about 13-14 years, while later a higher number of enlarged thyroids was found which may be classified as goitre endemy grade I.</p>","PeriodicalId":12104,"journal":{"name":"Experimental and clinical endocrinology","volume":"102 5","pages":"394-8"},"PeriodicalIF":0.0,"publicationDate":"1994-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1055/s-0029-1211310","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"18867047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Urinary excretion of hydroxy-pyridinium cross-links of collagen reflects skeletal growth velocity in normal children.","authors":"F Rauch,&nbsp;E Schönau,&nbsp;H Woitge,&nbsp;T Remer,&nbsp;M Seibel","doi":"10.1055/s-0029-1211269","DOIUrl":"https://doi.org/10.1055/s-0029-1211269","url":null,"abstract":"<p><p>Two new markers of bone resorption, the collagen cross-linking amino acids pyridinoline (PYD) and deoxypyridinoline (DPD), were measured in 24-h urine collections from 88 healthy children (45 females, 43 males; age 4 to 18 years) and 17 adults. Normal values for pediatric use were established for these parameters. Related to daily excretion of creatinine PYD and DPD were about 3 to 6 fold higher in the pediatric groups than in adults. The collagen cross-links showed a highly significant correlation to the urinary excretion of hydroxyproline (OHP): r = 0.65 for PYD and r = 0.60 for DPD (p < 0.001). Both collagen cross-links and OHP excretion related to creatinine were significantly correlated to growth velocity (r = 0.67, 0.62 and 0.51 for PYD, DPD and OHP respectively; p < 0.001 in each case). PYD and DPD may be useful for the monitoring of growth in children.</p>","PeriodicalId":12104,"journal":{"name":"Experimental and clinical endocrinology","volume":"102 2","pages":"94-7"},"PeriodicalIF":0.0,"publicationDate":"1994-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1055/s-0029-1211269","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19051117","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In vivo-effect of intraadrenal nicotine and substance P application on rat adrenal medullary catecholamine secretion.","authors":"J P Voigt,&nbsp;G Kaufmann,&nbsp;B Hirsch,&nbsp;S Leonhardt,&nbsp;H Jarry,&nbsp;P Oehme,&nbsp;W Wuttke","doi":"10.1055/s-0029-1211272","DOIUrl":"https://doi.org/10.1055/s-0029-1211272","url":null,"abstract":"<p><p>The present study was conducted to characterize in vivo the intraadrenal catecholamine (CA) secretion in rats. This was possible by using a microdialysis system (MDS) which mimics some properties of an artificial capillary. One end of this system was connected to a peristaltic pump, from the other end fractions were sampled at 5 min intervals. Concentrations of epinephrine (E) and norepinephrine (NE) in adrenal dialysate fractions were determined by HPLC electrochemical detection. Through this MDS nicotine was administered directly into the adrenal medulla of freely moving rats and the response of catecholamine release was determined. In the second part of the study the effect of exogenous substance P (SP) on spontaneous as well as on nicotine-stimulated CA release was investigated. Like nicotine, SP was administered directly into the adrenal medulla. At a flow rate of 25 microliter/min the transfer rates of CA and nicotine were approximately 1% whereas SP passed at a rate of 01.-0.2%. Under resting conditions CA release remained constant. In response to 2 x 10(-7) M nicotine (which resulted in local concentration of 2 x 10(-7) M), E and NE secretion increased 2.9 and 5.4-fold, respectively. However, due to an increased E response this difference attenuated with a later onset of the first stimulus. The higher concentrations of 10(-4) M resulted in 8.1 and 10.8-fold increases for E and NE. This latter response is clearly supraphysiologic and therefore the 2 x 10(-5) M concentration was used for further experimentation. CA secretion was stimulated with nicotine four times at 30 min intervals.(ABSTRACT TRUNCATED AT 250 WORDS)</p>","PeriodicalId":12104,"journal":{"name":"Experimental and clinical endocrinology","volume":"102 2","pages":"111-7"},"PeriodicalIF":0.0,"publicationDate":"1994-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1055/s-0029-1211272","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"18526506","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Placental progestagens in the sheep and horse and the changes leading to parturition.","authors":"M Silver","doi":"10.1055/s-0029-1211284","DOIUrl":"https://doi.org/10.1055/s-0029-1211284","url":null,"abstract":"<p><p>Placental progestagen production and metabolism during pregnancy, the changes which precede parturition and the extent of fetal involvement in the latter processes are compared in the sheep and the horse. Neither species requires the presence of a corpus luteum for maintenance of the latter part of pregnancy, but the mechanisms involved in placental progesterone/progestagen production are very different in the two species. In sheep the primary product is progesterone (P4), levels of which are high in the maternal but not the fetal circulations. By contrast, in the mare P4 is not detectable in maternal blood after 200 days gestation although it is present in the placenta and fetal circulation. A range of P4 metabolites (primarily 5 alpha-pregnanes) are produced by the equine placenta, while in the fetus pregnenolone and its metabolites are the predominant progestagens. In sheep the prepartum endocrine cascade in which the rise in fetal cortisol stimulates enzyme changes in the placenta so that P4 declines and estrogens and prostaglandins eventually rise, is fairly well established compared with the events preceding delivery in the mare. In the latter species there is a gradual rise in progestagens for 10-20 days before term, at a time when the fetal adrenal is relatively quiescent and unresponsive to ACTH i.e. fetal cortisol levels are low. In the last 24-48 h before delivery maternal progestagens fall, just after fetal plasma cortisol concentrations begin to escalate. The ways in which maternal and fetal prepartum endocrine changes may be interrelated and the possibility of a fetal trigger to parturition in the mare are discussed.</p>","PeriodicalId":12104,"journal":{"name":"Experimental and clinical endocrinology","volume":"102 3","pages":"203-11"},"PeriodicalIF":0.0,"publicationDate":"1994-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1055/s-0029-1211284","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"18990490","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nutritional regulation of uteroplacental prostaglandin production and metabolism in pregnant ewes and mares during late gestation.","authors":"A L Fowden,&nbsp;M M Ralph,&nbsp;M Silver","doi":"10.1055/s-0029-1211285","DOIUrl":"https://doi.org/10.1055/s-0029-1211285","url":null,"abstract":"<p><p>Prostaglandins (PGs) are produced by a variety of uteroplacental tissues during pregnancy and are released into the fetal fluid sacs and both the uterine and umbilical circulations. Uterine PG output increases towards term and is enhanced by maternal undernutrition in pregnant ewes and mares. In both species, withdrawal of food but not water for 30-48 h increases uterine venous PG levels and the uterine venous arterial concentration differences in PGE and 13, 14, dihydro-15-keto-prostaglandin F2 alpha (PGFM), the stable metabolite of PGF2 alpha. The increments in uterine V-A concentration differences in PGE and PGFM increase towards term and are associated with raised plasma PG levels in the fetal circulation. The PG changes observed during fasting are closely related to the fall in plasma glucose and the rise in plasma FFA in peripheral plasma. When normal metabolite levels are restored either by refeeding or glucose infusion, there is a rapid fall in PG levels with a narrowing of the uterine V-A concentration differences in the ewe and mare. When the data from all the animals are combined, there is an inverse correlation between uterine glucose uptake and PGFM output in both the pregnant ewe and mare. The availability of glucose and FFA to the gravid uterus therefore has an important role in controlling uteroplacental PG production and metabolism in late gestation although the specific steps in biochemical pathways regulated by these metabolites remain unclear. In the ewe, fasting increases uterine contractility and leads to early delivery of viable lambs in animals close to term (> 95% gestation), whereas in the mare it causes premature delivery of non-viable foals in most animals in late gestation (> 80% gestation). Nutritionally induced changes in uteroplacental PG production and metabolism therefore have important consequences for the outcome of pregnancy and may have a pivotal role in the induction of labour both before and at normal term.</p>","PeriodicalId":12104,"journal":{"name":"Experimental and clinical endocrinology","volume":"102 3","pages":"212-21"},"PeriodicalIF":0.0,"publicationDate":"1994-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1055/s-0029-1211285","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"18990491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Autoantibodies to glutamate decarboxylase detected in diabetes-prone BB/OK rats do not distinguish onset of diabetes.","authors":"M Ziegler,&nbsp;M Schlosser,&nbsp;J Hamann,&nbsp;P Vieregge,&nbsp;F Lühder,&nbsp;I Klöting,&nbsp;B Ziegler","doi":"10.1055/s-0029-1211270","DOIUrl":"https://doi.org/10.1055/s-0029-1211270","url":null,"abstract":"<p><p>The diabetes syndrome of the BB rat resembles human Type 1 (insulin-dependent) diabetes including the prevalence of autoantibodies to the 64 kDa Beta-cell autoantigen, which has been identified as glutamate decarboxylase. This study aimed at detecting the prevalence and level of glutamate decarboxylase autoantibodies in 120-day-old diabetic and non-diabetic diabetes-prone BB/OK rats compared to those of sex- and age-matched diabetes-resistant LEW.1A rats. The antibodies were detected using semipurified glutamate decarboxylase from rat brain in two immunoassays, a direct and a sandwich enzyme-linked immunosorbent assay. For the last assay autoantibody-containing immunoglobulins of a serum from a patient with the stiff-man syndrome were used to bind specifically the enzyme as autoantigen in plastic wells. The antibody levels measured as optical density at 490 nm (x +/- SD)/prevalence of the diabetic group (120 +/- 29 days of age) of BB/OK rats 0.57 +/- 0.29 (n = 51)/88% as well as those of the nondiabetic group (121 +/- 26 days of age) with 0.51 +/- 0.29 (n = 32)/97% was significantly increased (p < 0.01) compared to those of the diabetes-resistant control group 0.15 +/- 0.06 (n = 29)/0%. Furthermore in a 209 +/- 27-day-old group (n = 21) of non-diabetic but diabetes-prone BB/OK rats the autoantibody levels of 1.21 +/- 0.39 vs 0.51 +/- 0.26 were further significantly enhanced (p < 0.01). These results were confirmed by a sandwich assay.(ABSTRACT TRUNCATED AT 250 WORDS)</p>","PeriodicalId":12104,"journal":{"name":"Experimental and clinical endocrinology","volume":"102 2","pages":"98-103"},"PeriodicalIF":0.0,"publicationDate":"1994-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1055/s-0029-1211270","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19051118","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Plasma levels of benperidol, prolactin, and homovanillic acid after intravenous versus two different kinds of oral application of the neuroleptic in schizophrenic patients.","authors":"W Seiler,&nbsp;H Wetzel,&nbsp;A Hillert,&nbsp;G Schöllnhammer,&nbsp;O Benkert,&nbsp;C Hiemke","doi":"10.1055/s-0029-1211299","DOIUrl":"https://doi.org/10.1055/s-0029-1211299","url":null,"abstract":"<p><p>Plasma levels of prolactin (PRL) and the butyrophenone neuroleptic benperidol (BPD) were closely followed 0 to 48 h after acute application of 6 mg BPD as intravenous injection, orally as liquid, and orally as tablets in 12 schizophrenic patients using a partially randomized cross over design. Drug concentrations showed application specific pharmacokinetic behavior with complete elimination within 48 h. All three applications led to a biphasic PRL response with pronounced initial plasma PRL peaks returning to baseline levels within 48 h. The results suggest that after acute neuroleptic challenge BPD plasma levels as low as 2-3 ng/ml can be sufficient for complete depletion of pituitary PRL stores. This initial peak was followed by a PRL plateau about twice above pretreatment values indicating doubling of the PRL synthesis and secretion independent of supraeffective actual BPD concentrations. The PRL plateau persisted as long as BPD concentrations were above those levels which triggered the initial PRL response. As compared with the time of maximum concentrations (tmax) for BPD, the PRL tmax was later after i.v. injection, equal after liquid application, and earlier after tablet administration leading to pronounced application specific differences in shape, direction, and position of resulting hysteresis curves. Plasma levels of homovanillic acid (HVA) were not affected by BPD treatment. The PRL and HVA levels registered after acute doses of BPD indicated that the hormone responses were most likely the result of acute depletion of PRL stores and subsequent stimulation of hormone synthesis whereas it seemed unlikely that dopaminergic activities were relevant.</p>","PeriodicalId":12104,"journal":{"name":"Experimental and clinical endocrinology","volume":"102 4","pages":"326-33"},"PeriodicalIF":0.0,"publicationDate":"1994-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1055/s-0029-1211299","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"18815601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}