Identification of the thyrotropin-releasing-hormone-degrading
نویسنده
چکیده
A time-dependent inhibition of the thyrotropin-releasing-hormone (TRH)-degrading ectoenzyme (EC 3.4.19.-) from rat brain by the metal-complexing agents imidazole, NaCN, EDTA and 1,10-phenanthroline could be demonstrated. In contrast, the inhibition by the non-chelating analogues 4,7and 1,7-phenanthroline was not time-dependent. At a concentration of 100 ,M EDTA the enzymic activity decreased by 50% only after pretreatment for 6 h. It could be restored by addition of Zn2+, Ni2+ and Co2+ but not by other transition metal ions and also not by Ca2+ and Mg2+. Without pretreatment, the enzyme was activated by Co2+ and inhibited by Cu2+, Cd2+ and Hg2+ in a time-dependent manner, but remained unaffected by Ni2+ and
منابع مشابه
The Therapeutic Effect of Thyrotropin Releasing Hormone in Amyotrophic Sclerosis
Although the issue has not yet been fully resolved, there is reason to believe that TRI-I may have a trophic effect on the normal motoneuron and may transien tly improve the neurologic deficit in ALS. Since ALS is not a simple TRI-I deficiency disease, this improvement probably occurs via a secondary mecha -nism-possibly another neurotransmitter. It is uncertain at this time whether this effec...
متن کاملLower levels of thyrotropin-releasing hormone-degrading activity in human cord and in maternal sera than in the serum of euthyroid, nonpregnant adults.
Thyrotropin-releasing hormone (TRH)-degrading activity was investigated in human cord, maternal, and euthyroid adult sera by measuring (a) the rate of disappearance of TRH and (b) the rate of formation of degradation products. The rate of TRH degradation in cord and maternal sera was 25-33% of that in euthyroid adult serum. Concomitantly, in cord and maternal sera, the rate of formation of prol...
متن کاملEffect of Aerobic Exercise on Thyroid Hormones and Quality of Life in Obese Postmenopausal Women
ABSTRACT Background and objectives: Studies have shown that exercise can affect hormone secretion and some metabolic and endocrine functions. The aim of this study was to assess the effect of eight weeks of aerobic training on thyroid hormones and quality of life in obese postmenopausal women. Methods: In this semi-experimental study, 21 obese (body mass index >30 Kg/m2)...
متن کاملPurification and characterization of the thyrotropin-releasing hormone (TRH)-degrading serum enzyme and its identification as a product of liver origin.
Previous biochemical studies have indicated that the membrane-bound thyrotropin-releasing hormone (TRH)-degrading enzyme (TRH-DE) from brain and liver and the serum TRH-DE are derived from the same gene. These studies also suggested that the serum enzyme is of liver origin. The present study was undertaken to verify these hypotheses. In different species, a close relationship between the activi...
متن کاملSecondary amenorrhea in a woman with spinocerebellar degeneration treated with thyrotropin-releasing hormone: a case report and in vitro analysis
INTRODUCTION While thyrotropin-releasing hormone is known to be a prolactin-release stimulating factor, thyrotropin-releasing hormone-tartrate and its derivative, taltirelin hydrate, are used for the treatment of spinocerebellar degeneration, a degenerative disease characterized mainly by motor ataxia. We report the case of a patient being treated with a thyrotropin-releasing hormone preparatio...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2005