A Corbin, F J Bex, J P Yardley, R W Rees, T J Foell, D Sarantakis
{"title":"Agonist (ovulation induction) and post-coital contraceptive properties of [D-Ala6] and [D-Trp6]-LHRH series.","authors":"A Corbin, F J Bex, J P Yardley, R W Rees, T J Foell, D Sarantakis","doi":"10.3109/07435807909070880","DOIUrl":"https://doi.org/10.3109/07435807909070880","url":null,"abstract":"<p><p>Seven derivatives of LH-RH, representing the [D-Ala6] or [D-Trp6] series, with or without a Fujino modification, were evaluated for ovulation-inducing (agonist and post-coital contraceptive activity in rats. Six of these analogues had a high degree of agonist and pregnancy-terminating potency. In general, several modifications can result in a particular series of composite molecules that possess a biologic potency greater than each of its predecessors; this correlation of structure with activity was more consistent in the [D-Ala6]-series than in the [D-Trp6]-series. The relationship between structural modifications, resistance to enzyme degradation (based on literature reports) and increased biologic potency is discussed.</p>","PeriodicalId":75821,"journal":{"name":"Endocrine research communications","volume":"6 1","pages":"1-14"},"PeriodicalIF":0.0,"publicationDate":"1979-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3109/07435807909070880","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"11591943","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":"Diurnal rhythm of pituitary-thyroid axis in male rats and the effect of adrenalectomy.","authors":"S Ooka-Souda, D J Draves, P S Timiras","doi":"10.3109/07435807909070883","DOIUrl":"https://doi.org/10.3109/07435807909070883","url":null,"abstract":"<p><p>Levels of TSH, thyroxine (T4) and triiodothyronine (T3) were measured by radioimmunoassay in plasma (TSH, T4, T3) and pituitary (TSH) of 60-day old male Long-Evans rats. Definite diurnal rhythms were demonstrated in pituitary TSH, plasma TSH and T3 in intact rats, evidenced by the statistically significant differences between zenith and nadir for pituitary TSH, plasma TSH and T3. The zenith value of pituitary TSH and the nadir values of plasma TSH, T4 and T3 were observed at the same time (2400 h) as were the nadir value of pituitary TSH and the zenith values of plasma TSH, T4, and T3 (at 1200 h). Our results indicate that the rhythmicity of pituitary TSH content is a mirror image of that of plasma TSH. Adrenalectomy not only reduced plasma corticosterone levels to almost zero, but also decreased plasma T3 and T4 levels. In adrenalectomized rats, the absolute concentration of pituitary and plasma TSH increased at 1200 h and at 2400 h and, in both cases, the difference between values at 1200 h and at 2400 h persisted. The differences in plasma TSH, T3 and T4 between 1200 h and 2400 h were also observed in sham-adrenalectomized rats. These results suggest glucocorticoids do influence the pituitary-thyroid axis, but that the rhythmicity of the pituitary-thyroid axis does not seem to depend on the rhythmicity of glucocorticoid secretion.</p>","PeriodicalId":75821,"journal":{"name":"Endocrine research communications","volume":"6 1","pages":"43-56"},"PeriodicalIF":0.0,"publicationDate":"1979-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3109/07435807909070883","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"11777247","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":"Radioimmunoassay of ovine and bovine serum progesterone without extraction and chromatography.","authors":"B D Schanbacher","doi":"10.1080/07435807909061106","DOIUrl":"https://doi.org/10.1080/07435807909061106","url":null,"abstract":"<p><p>A procedure for the radioimmunoassay of ovine and bovine serum progesterone is described which does not require extraction and chromatography. Serum samples are assayed directly, and a highly specific antiserum that was prepared in rabbits against 11 alpha-hydroxyprogesterone conjugated to bovine serum albumin is used. Interference from serum binding proteins is alleviated by use of a phosphate buffer containing 5% BSA and separation of bound and free tritiated progesterone by a double antibody procedure. Serum samples are assayed in a mini-vial, the bound fraction (double antibody precipitate) is mixed with scintillation solution and the radioactivity is counted in the same vial. The assay procedure is sensitive (10 pg, 100 pg/ml) and has acceptable accuracy and precision. Because there is no extraction or chromatography, serum progesterone is not lost. Most important, the procedure is specific for progesterone and measures serum progesterone concentrations in the ewe and cow which are comparable with those obtained with conventional assay techniques. The progesterone assay described herein provides a rapid, economical procedure that can facilitate the study of ovarian cyclicity and aid in the early diagnosis of pregnancy.</p>","PeriodicalId":75821,"journal":{"name":"Endocrine research communications","volume":"6 4","pages":"265-77"},"PeriodicalIF":0.0,"publicationDate":"1979-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/07435807909061106","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"11748161","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":"A sensitive, convenient radioimmunoassay procedure which demonstrates that serum hTSH is suppressed below the normal range in thyrotoxic patients.","authors":"R E Wehmann, H A Rubenstein, B C Nisula","doi":"10.3109/07435807909061799","DOIUrl":"https://doi.org/10.3109/07435807909061799","url":null,"abstract":"<p><p>A highly sensitive radioimmunoassay procedures for the measurement of serum hTSH is described which permits delineation of the entire range of values in normal subjects (0.5-4.5 microU/ml). The procedure involves the concentration of hTSH from serum by adsorption to concanavalin A covalently bound to 4B Sepharose, Lactoperoxidase iodination of hTSH, and disequilibrium assay conditions. This method utilizes commonly available radioimmunoassay materials and is convenient to perform. Our results with this assay show that patients with thyrotoxicosis of a variety of etiologies have serum hTSH levels suppressed well below the normal range.</p>","PeriodicalId":75821,"journal":{"name":"Endocrine research communications","volume":"6 3","pages":"249-55"},"PeriodicalIF":0.0,"publicationDate":"1979-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3109/07435807909061799","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"11724918","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":"The follicular iodide pool as a two-compartment system: evidence from the unstimulated thyroid gland.","authors":"C Simon, P Bastiani","doi":"10.1080/07435807909061102","DOIUrl":"https://doi.org/10.1080/07435807909061102","url":null,"abstract":"<p><p>The isotopic equilibrium method was used for a 60-day period to follow iodine turnover in control and hypophysectomized rats. After the suppression of TSH by hypophysectomy, only the captured iodide is used for iodination of thyroglobulin, the iodide recycling being abolished. In unstimulated gland, two metabolically distinct iodide compartments do exist which differ either in their chemical form or in their morphological distribution, or both.</p>","PeriodicalId":75821,"journal":{"name":"Endocrine research communications","volume":"6 2","pages":"149-58"},"PeriodicalIF":0.0,"publicationDate":"1979-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/07435807909061102","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"11714170","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":"Reconstitution of the solubilized insulin receptor in phospholipid vesicles.","authors":"R J Gould, B H Ginsberg, A A Spector","doi":"10.1080/07435807909061107","DOIUrl":"https://doi.org/10.1080/07435807909061107","url":null,"abstract":"<p><p>The insulin receptor was solubilized from turkey erythrocyte membranes by extraction with 1% beta-octylglucopyranoside. Insulin binding was enhanced when the solubilized material was reconstituted in phospholipid vesicles. The affinity of the reconstituted vesicles for various insulins was similar to that of the intact membranes: porcine insulin greater than proinsulin greater than desoctapeptide insulin. A curvilinear Scatchard plot was obtained for insulin binding to the reconstituted system at 15 degrees C. A high affinity association constant of 1.4 x 10(9) M-1 was obtained from the Scatchard plot. This is a four-fold increase over the value for the turkey erythrocyte membrane, which contains more highly saturated phospholipids. This suggests that the insulin receptor may be sensitive to the lipid composition of the membranes in which it is embedded.</p>","PeriodicalId":75821,"journal":{"name":"Endocrine research communications","volume":"6 4","pages":"279-90"},"PeriodicalIF":0.0,"publicationDate":"1979-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/07435807909061107","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"11604678","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":"Evaluation of in vitro incubation systems for the study of gonadotropin release.","authors":"J L O'Conner, M B Allen, V B Mahesh","doi":"10.3109/07435807909070881","DOIUrl":"https://doi.org/10.3109/07435807909070881","url":null,"abstract":"<p><p>A detailed study was undertaken in order to determine if a pituitary-half incubation system were a suitable model for the study of anterior pituitary response to estradiol and LHRH. Considerable variation in the gonadotropin content of randomized pituitary halves was observed. Much less variation was found in matched halves. During the initial thirty minutes incubation of pituitary halves, a large spontaneous release of gonadotropins was observed. Time course secretion studies indicated that by four hours incubation, in the presence of 50 ng/ml LHRH, cumulative secretion of LH and FSH had far exceeded that of controls. Elevations in both cumulative secretion and rate of secretion were evident within 15-30 minutes of incubation. Regardless of LHRH dose, only 2-4% of either gonadotropin was secreted. Estradiol in the range of 10, 100, 500, 1,000 and 50,000 pg/ml had no significant effect on pituitary response to LHRH or on basal release, tissue levels or total gonadotropin. Based on these results, it was concluded that while the pituitary-half incubation system may be suitable for studying LHRH induced gonadotropin secretion, it is apparently of insufficient sensitivity to allow the collection of meaningful data concerning the effects of estradiol alone on gonadotropin secretion or estradiol modulation of LHRH induced gonadotropin secretion.</p>","PeriodicalId":75821,"journal":{"name":"Endocrine research communications","volume":"6 1","pages":"15-36"},"PeriodicalIF":0.0,"publicationDate":"1979-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3109/07435807909070881","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"11591944","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 patterns of circulating steroids in adult male rats III. Effect of total parenteral nutrition on the diurnal variation of testosterone.","authors":"R J Keating, R K Tcholakian","doi":"10.1080/07435807909061098","DOIUrl":"https://doi.org/10.1080/07435807909061098","url":null,"abstract":"<p><p>The in vivo pattern of circulating testosterone (T) during a 24 hr period was investigated in stock-fed and total parenterally nourished (TPN) rats. A diurnal rhythm of T was observed in control rats with highest concentrations occurring during the dark period. The loss of this rhythm in rats maintained on TPN shows that nutritional regimen affects circulating T and overrides the synchronizing effect of the light/dark cycle.</p>","PeriodicalId":75821,"journal":{"name":"Endocrine research communications","volume":"6 2","pages":"95-105"},"PeriodicalIF":0.0,"publicationDate":"1979-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/07435807909061098","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"11336550","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":"The fate of fertilized ova in rats receiving luteinizing hormone-releasing hormone (LRH).","authors":"R C Jones","doi":"10.1080/07435807909061103","DOIUrl":"https://doi.org/10.1080/07435807909061103","url":null,"abstract":"<p><p>The development and eventual fate of unimplanted fertilized ova in rats receiving pregnancy-inhibiting doses of luteinizing hormone-releasing hormone (LRH) were studied during the first 14 days of gestation. The results suggest that LRH accelerates passage of ova through the oviducts. Also, the zona pellucida of treated animals is retained by the majority of ova until day 7; zona-encased ova were observed as late as day 10. Elimination of the ova appears to occur by expulsion with uterine fluids through the vagina upon the animals' return to estrus.</p>","PeriodicalId":75821,"journal":{"name":"Endocrine research communications","volume":"6 2","pages":"159-67"},"PeriodicalIF":0.0,"publicationDate":"1979-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/07435807909061103","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"11595793","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}
G Tolis, K Banovac, P Kleissl, J B Martin, J M McKenzie
{"title":"Episodic and TRH induced growth hormone release in primary hypothyroidism of man and rat.","authors":"G Tolis, K Banovac, P Kleissl, J B Martin, J M McKenzie","doi":"10.3109/07435807909061796","DOIUrl":"https://doi.org/10.3109/07435807909061796","url":null,"abstract":"<p><p>In 27 hypothyroid subjects studied over 20 to 120 minutes, the concentration of serum growth hormone (GH) was variable with the amplitude and frequency of the secretory patterns similar to those reported by others for normal individuals. Serum GH, after the administration of thyrotropin releasing hormone (TRH) did not differ from values observed as spontaneous surges, in contrast to a consistent increase in thyrotropin and prolactin. Episodic secretion of GH persisted in thyroidectomized rats and did not differ significantly from that present in intact controls. It is concluded that episodic GH secretion is not abolished in primary hypothyroidism and that TRH is not a constant GH secretagogue in human subjects with hypothyroidism.</p>","PeriodicalId":75821,"journal":{"name":"Endocrine research communications","volume":"6 3","pages":"213-26"},"PeriodicalIF":0.0,"publicationDate":"1979-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3109/07435807909061796","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"11337439","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}