甲状腺功能亢进和减退兔的血清血管紧张素转换酶及血浆心钠素水平

Yeğin E, Yiğitoğlu R, Ari Z, Celik I, Akçay F, Süzek H

Department of Biochemistry, Science Faculty, University of 100.Yil, Van, Turkey.

Jpn Heart J. 1997 Mar;38(2):273-9.

BACKGROUND

It is known that serum angiotensin-converting enzyme (ACE), and plasma atrial natriuretic peptide (p-ANP) levels increase in hyperthyroidism. However, the precise mechanism of the effects of thyroid hormone on ANP release remains to be clarified. No study investigating serum ACE together with p-ANP levels has been performed in experimental hyperthyroid and hypothyroid rabbits. The present study was designed in order to provide additional evidence of increased ANP production and secretion in hyperthyroidism and to investigate the relationships between ANP, ACE and thyroid hormones.

METHODS

Male New Zealand white rabbits (2.3-3.4 kg) were used throughout the study. Hyperthyroidism was induced by daily intraperitoneal administration of L-thyroxin (50 micrograms/100 g). Hypothyroidism was induced by daily intraperitoneal injection of propylthiouracil (2 mg/100 g body weight). Twelve days after the end of treatment, animals were sacrificed under anesthesia and blood samples were obtained from the aorta for serum ACE and thyroid hormone and p-ANP determinations.

RESULTS

Serum ACE, plasma renin activity (PRA) and p-ANP were higher in hyperthyroid rabbits and lower in hypothyroid rabbits than in euthyroid rabbits. ANP concentration in atria was lower in hyperthyroid rabbits and higher in hypothyroid rabbits than in euthyroid rabbits. p-ANP, PRA and serum ACE levels were positively correlated with serum thyroxin levels. Inverse correlation was found between serum thyroxin and ANP concentration in atria (a-ANP), and between p-ANP and a-ANP.

CONCLUSIONS

Our results indicate that not only p-ANP but also serum ACE activity was markedly increased in experimental hyperthyroid rabbits. It was thought that there were both direct and indirect effects of thyroxin on the release of ANP.

背景

已知甲状腺功能亢进时血清血管紧张素转换酶（ACE）和血浆心房利钠肽（p-ANP）水平会升高。然而，甲状腺激素对心房利钠肽释放影响的确切机制仍有待阐明。尚未有研究在实验性甲状腺功能亢进和甲状腺功能减退的兔子中同时检测血清ACE和p-ANP水平。本研究旨在为甲状腺功能亢进时心房利钠肽产生和分泌增加提供更多证据，并研究心房利钠肽、ACE与甲状腺激素之间的关系。

方法

整个研究使用雄性新西兰白兔（体重2.3 - 3.4千克）。通过每日腹腔注射L-甲状腺素（50微克/100克）诱导甲状腺功能亢进。通过每日腹腔注射丙硫氧嘧啶（2毫克/100克体重）诱导甲状腺功能减退。治疗结束12天后，动物在麻醉下处死，从主动脉采集血样用于测定血清ACE、甲状腺激素和p-ANP。

结果

甲状腺功能亢进的兔子血清ACE、血浆肾素活性（PRA）和p-ANP高于甲状腺功能正常的兔子，而甲状腺功能减退的兔子则低于甲状腺功能正常的兔子。甲状腺功能亢进的兔子心房中的心房利钠肽浓度低于甲状腺功能正常的兔子，而甲状腺功能减退的兔子则高于甲状腺功能正常的兔子。p-ANP、PRA和血清ACE水平与血清甲状腺素水平呈正相关。血清甲状腺素与心房中的心房利钠肽浓度（a-ANP）之间以及p-ANP与a-ANP之间呈负相关。