Endocrinologia experimentalis最新文献_第6页

Feedback control of gonadotropin secretion in mammalian and human males: effects of gonadotropin receptor blockers. 哺乳动物和人类雄性促性腺激素分泌的反馈控制:促性腺激素受体阻滞剂的作用。

Endocrinologia experimentalis Pub Date : 1990-03-01

A Reznikov

{"title":"Feedback control of gonadotropin secretion in mammalian and human males: effects of gonadotropin receptor blockers.","authors":"A Reznikov","doi":"","DOIUrl":"","url":null,"abstract":"Non-steroidal antiandrogens (NAA), flutamide and hydroxy-flutamide were used to study involvement of androgenic receptors in feedback control of gonadotropin secretion in males. In castrated animals these blockers inhibited the uptake of tritiated testosterone (T) by the hypothalamus and adenohypophysis. In male rats with intact gonads the NAA were found to reduce inhibitory effects of circulating endogenous androgens on the hypothalamus and pituitary gland which resulted in the increase of plasma LH, FSH and T levels, enhanced pituitary sensitivity to intravenously injected LHRH, increased activity of testicular steroid-delta 5-3 beta-ol-dehydrogenase. Endocrine response appeared the most pronounced in rats and was less marked in other animals species, and also in humans. No response was revealed in hypophysectomized male rats. Deafferentation of mediobasal hypothalamus by Halász knife had no impact on increased plasma T level following exposure to NAA. Furthermore, electrolytic destruction of arcuate nucleus and median eminence prevented or diminished significantly stimulation of LH, FSH and T secretion in NAA treated male rats. The results of this study suggest that androgenic receptors of mediobasal hypothalamus and pituitary gland are involved in control of gonadotropin secretion by circulating male sex hormones.","PeriodicalId":11547,"journal":{"name":"Endocrinologia experimentalis","volume":"24 1-2","pages":"267-73"},"PeriodicalIF":0.0,"publicationDate":"1990-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13268666","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}

引用次数: 0

Influence of thyroid hormone supply on EEG frequency spectrum. 甲状腺激素供给对脑电图频谱的影响。

Endocrinologia experimentalis Pub Date : 1989-12-01

D Pohunková, J Sulc, S Vána

{"title":"Influence of thyroid hormone supply on EEG frequency spectrum.","authors":"D Pohunková, J Sulc, S Vána","doi":"","DOIUrl":"","url":null,"abstract":"In 5 patients after total thyroidectomy followed by radioiodine ablation the frequency analysis of EEG based on fast Fourier transformation was performed and the results obtained during hypothyroid state and after the substitution treatment with thyroid hormones were compared. During the hypothyroid state the most remarkable finding was the increase of percentage representation of fast frequencies in beta 1 and beta 2 bands, while such values in alpha band including a dominant frequency in that band were reciprocally decreased. After the period of treatment with triiodothyronine during which clinically euthyroid state has been achieved (i.e. decrease of Achilles tendon reflex time, decrease of TSH and of T3 level) no significant changes in the distribution of EEG frequencies spectrum were found, but in all patients a dominant frequency in alpha band was increased at least for 1 Hz. Only after the treatment with thyroxine (Eltroxin Glaxo) the interrelations between individual frequencies of EEG spectrum returned to the normal range and a further increase in dominant alpha frequency was found. The correlation between a dominant frequency in alpha band and thyroxine level in serum was highly significant. These findings are in agreement with our previous observations in 43 subjects where a dominant alpha frequency in healthy controls was always higher than that in hypothyroid subjects and was significantly related to T4 level. The findings of continuing EEG signs of brain hypothyroidism even after achieving of clinical euthyroidism and normal peripheral parameters under increased serum T3 and low T4 level are in full agreement with experimental observations on the importance of local deiodination of T4 in brain tissue and on the risk of hypothyroxinemia.(ABSTRACT TRUNCATED AT 250 WORDS)","PeriodicalId":11547,"journal":{"name":"Endocrinologia experimentalis","volume":"23 4","pages":"251-8"},"PeriodicalIF":0.0,"publicationDate":"1989-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13763373","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}

引用次数: 0

Thyroid functional status and TSH receptors of cold nodular tissue. 冷结节组织的甲状腺功能状态和TSH受体。

Endocrinologia experimentalis Pub Date : 1989-12-01

S Djurica, D Misković, M Ratković, N Ribarac-Stepić

引用次数: 0

Effect of 1,25-dihydroxycholecalciferol on fracture healing and on general posttraumatic skeletal response in rats. 1,25-二羟基胆骨化醇对大鼠骨折愈合及一般创伤后骨骼反应的影响。

Endocrinologia experimentalis Pub Date : 1989-12-01

J Blahos, A Babický, I Porsová, J Kolár

{"title":"Effect of 1,25-dihydroxycholecalciferol on fracture healing and on general posttraumatic skeletal response in rats.","authors":"J Blahos, A Babický, I Porsová, J Kolár","doi":"","DOIUrl":"","url":null,"abstract":"The authors investigated the effect of 1,25-dihydroxycholecalciferol (1,25(OH)2D3) on the local healing process following an artificial fracture of the rat tibia and on the general posttraumatic response of the skeleton to local trauma. The results showed a significant increase in dry weight of fractured tibias as compared with contralateral intact bones which was due to the newly formed callus. 1,25(OH)2D3 significantly increased the weights of tibias which can be explained by its stimulatory effect on callus formation. The uptake of 85Sr into bones resembling the metabolic pathways of calcium was significantly higher in fractured bones as compared with intact ones. 1,25(OH)2D3 significantly reduced the uptake of 85Sr. There was a significantly higher whole body retention of 85Sr in the rats with fractured bones. The administration of 1,25(OH)2D3 significantly reduced the retention of 85Sr in the fractured bone and the concomitant reduction of the whole body retention of 85Sr most likely reflected the increase in intestinal calcium absorption induced by 1,25(OH)2D3 with the consequent decrease in the specific activity of 85Sr administered in a single injection. The general posttraumatic response was reflected by increased dry weight of non-fractured bones. 1,25(OH)2D3 showed a contributory effect on this increase which may indicate that the general response consisted in increased bone formation. The uptake of 85Sr in non-fractured bones was reduced which was also most probably due to a decrease of specific activity of 85Sr. 1,25(OH)2D3 significantly accentuated the reduction of the uptake.(ABSTRACT TRUNCATED AT 250 WORDS)","PeriodicalId":11547,"journal":{"name":"Endocrinologia experimentalis","volume":"23 4","pages":"287-94"},"PeriodicalIF":0.0,"publicationDate":"1989-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13764077","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}

引用次数: 0

Apparatus for blood sampling from small laboratory animals during gravitational overload. 重力过载时小型实验动物血液取样装置。

Endocrinologia experimentalis Pub Date : 1989-12-01

K Murgas, I Padúch

引用次数: 0

Study of the role of tryptophanyl and arginyl residues in the specific binding of 3,5,3'-triiodothyronine to rat liver nuclear receptors. 色氨酸残基和精氨酸残基在3,5,3'-三碘甲状腺原氨酸与大鼠肝核受体特异性结合中的作用研究。

Endocrinologia experimentalis Pub Date : 1989-12-01

J Brtko, J Knopp, V Kéry

{"title":"Study of the role of tryptophanyl and arginyl residues in the specific binding of 3,5,3'-triiodothyronine to rat liver nuclear receptors.","authors":"J Brtko, J Knopp, V Kéry","doi":"","DOIUrl":"","url":null,"abstract":"The role of tryptophane and arginine residues of rat liver receptors for the specific binding of 3,5,3'-triiodothyronine (T3) was studied by chemically modifying the receptor molecule. Soluble T3 receptor fraction was prepared from purified rat liver nuclei and the kinetics of the modification of a tryptophane indol ring of nuclear receptor by N-bromsuccinimide (NBS) in the presence of excess -SH protecting agent was examined. Moreover the kinetics of the formation of N5-(4-oxo-1,3-diazospiro[4,4]non-2-ylidene)-I-ornithine or N7,N8-(1,2-dihydroxycyclohexyl-1,2-ylene)-L-arginine from arginine residue(s) of nuclear receptor by 1,2-cyclohexanedione was investigated. The efficiency of the reactions were followed spectrophotometrically and the modified nuclear receptor fraction separated from chemical modifiers on a Sephadex G-25 column was assayed at pH 8.0 for T3 specific binding. The T3 specific binding was tested by Scatchard plot analysis. No changes in nuclear receptor Ka or MBC were observed after 1,2-cyclohexanedione treatment. Tryptophanyl residue(s) of the receptor molecule may play an effective role in the maintaining the nuclear receptor in a conformation optimal for T3 binding.","PeriodicalId":11547,"journal":{"name":"Endocrinologia experimentalis","volume":"23 4","pages":"259-67"},"PeriodicalIF":0.0,"publicationDate":"1989-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13763374","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}

引用次数: 0

Glycosaminoglycans in urine, articular and periarticular tissues in streptozotocin diabetes in rats. 链脲佐菌素糖尿病大鼠尿液、关节及关节周组织中的糖胺聚糖。

Endocrinologia experimentalis Pub Date : 1989-12-01

M E Mavrikakis, D Kontoyannis, J Karli, C Kittas, E Giagiakou, A Moulopoulou, D A Koutras

{"title":"Glycosaminoglycans in urine, articular and periarticular tissues in streptozotocin diabetes in rats.","authors":"M E Mavrikakis, D Kontoyannis, J Karli, C Kittas, E Giagiakou, A Moulopoulou, D A Koutras","doi":"","DOIUrl":"","url":null,"abstract":"Experimental data support the hypothesis that insulin deficiency increases the degradation of glycosaminoglycans (GAGs) and decreases their synthesis. The purpose of this study was to investigate the effect of streptozotocin-induced experimental diabetes on mucopolysaccharide content of the articular and periarticular tissues as well as on the urine GAGs excretion. In two groups (A and B) of ten white Wistar rats, experimental diabetes was induced after administration of streptozotocin in a dose of 65 and 45 mg/kg of body weight, respectively. The animals of group A (short term diabetes) and B (long term diabetes) were sacrificed on the 8th and 87th day of the experimental procedure respectively. GAGs were determined in urine specimens collected before and on the 8th day in group A and before and on 3rd, 8th, 16th, 23rd, 36th, 52nd, 71st and the 87th day in group B. At the end of the experiment articular and periarticular tissue specimens were examined for changes in their mucopolysaccharides content and compared to a group of five animals of the same age and dietary conditions (control group, C). We found a marked increase (P less than 0.001) of urine GAGs excretion during streptozotocin-induced diabetes as compared to the respective values before the experiment in both groups, while in group B a positive relationship (P less than 0.001) between 24 hour urine GASGs excretion, and the duration of diabetes was observed. The histochemistry of the articular and periarticular tissues revealed marked decrease in GAGs content, as well as hardening of the tendons.","PeriodicalId":11547,"journal":{"name":"Endocrinologia experimentalis","volume":"23 4","pages":"295-304"},"PeriodicalIF":0.0,"publicationDate":"1989-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13678846","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}

引用次数: 0

Localization of different releasing hormone immunoreactive (LH-IR) neurons and their projections in central nervous system of birds. A mini-review. 鸟类中枢神经系统不同释放激素免疫反应(LH-IR)神经元的定位及其投射。本文着重。

Endocrinologia experimentalis Pub Date : 1989-12-01

B Mess, R Józsa

引用次数: 0

Comparison of the effect of amiodarone and benziodarone on thyroxine metabolism and surface ECG. 胺碘酮与苯碘酮对甲状腺素代谢及体表心电图影响的比较。

Endocrinologia experimentalis Pub Date : 1989-12-01

S D Moulopoulos, D A Koutras, S Stamatelopoulos, A Souvatzoglou, G D Piperingos, G Philippou

{"title":"Comparison of the effect of amiodarone and benziodarone on thyroxine metabolism and surface ECG.","authors":"S D Moulopoulos, D A Koutras, S Stamatelopoulos, A Souvatzoglou, G D Piperingos, G Philippou","doi":"","DOIUrl":"","url":null,"abstract":"This study examined whether or not the electrophysiological effect of amiodarone on the heart is mediated through its action on thyroxine metabolism. Serum thyroid hormones and ECG were evaluated before and serially during amiodarone (15 subjects) and benziodarone (15 subjects) administration. Both amiodarone and benziodarone shifted the peripheral conversion of thyroxine (P less than 0.001 for amiodarone and P less than 0.001 for benziodarone) towards reverse triiodothyronine and away from triiodothyronine, whilst TSH levels initially fell and then rose with both drugs. After amiodarone the heart rate decreased (P less than 0.025), whilst the PR (P less than 0.005) and the QT interval (P less than 0.005) corrected for the heart rate increased. By contrast with benziodarone only the PR interval decreased (P less than 0.05). Since both drugs had roughly similar effects on thyroid hormone metabolism but different ones on the ECG, our results provide indirect evidence against the hypothesis that the antiarrhythmic effects of amiodarone are mediated through a decrease in the serum T3 presented to the peripheral tissues.","PeriodicalId":11547,"journal":{"name":"Endocrinologia experimentalis","volume":"23 4","pages":"269-78"},"PeriodicalIF":0.0,"publicationDate":"1989-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13764073","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}

引用次数: 0

Prevention of experimental calcinosis by salmon calcitonin in rats. 鲑鱼降钙素对大鼠实验性钙化症的预防作用。

Endocrinologia experimentalis Pub Date : 1989-12-01

A Czirfusz, V Kovalcík, S Galbavý, E Drábková

引用次数: 0