Bataillard A, Sacquet J, Julien C, Vincent M, Gomez-Sanchez C, Touraine J L, Sassard J
Department of Physiology and Clinical Pharmacology, CNRS URA 1483, School of Pharmacy, Lyon, France.
Am J Hypertens. 1993 May;6(5 Pt 1):407-12. doi: 10.1093/ajh/6.5.407.
Previous studies showed that neonatal thymectomy prevented the spontaneous increase in blood pressure in genetically hypertensive rats (LH) of the Lyon strain, leaving untouched that of their normotensive controls (LN). As the thymus is connected to the neuroendocrine system through secretion of hormonal factors, we investigated the possible role played by these factors in hypertension of LH rats. To that end we studied, in sham-operated and neonatally thymectomized LH rats, the blood pressure effects of thymostimulin, a partially purified thymus extract and examined whether changes in major neuroendocrine factors of blood pressure regulation occurred in thymectomized LH rats. Thymostimulin (1 or 10 mg/kg/48 h) did not modify blood pressure in sham-operated LH rats and failed to consistently increase it in neonatally thymectomized animals. Urinary mineralocorticoids, catecholamines and their metabolites, and plasma renin levels were not altered by neonatal thymectomy. Plasma testosterone was decreased to a similar degree by neonatal thymectomy in LH and normotensive controls. These results do not favor a pressor role of thymic hormonal factors in LH rats and show that the antihypertensive effect of neonatal thymectomy is not secondary to a decreased secretion of catecholamines, renin, mineralocorticoids, and testosterone. They therefore suggest that the role of the thymus in genetically hypertensive LH rats is more likely mediated by cellular immune mechanisms than by hormonal processes.
先前的研究表明，新生期胸腺切除可防止里昂品系遗传性高血压大鼠（LH）血压的自发性升高，而其正常血压对照大鼠（LN）的血压则不受影响。由于胸腺通过激素因子的分泌与神经内分泌系统相连，我们研究了这些因子在LH大鼠高血压中可能发挥的作用。为此，我们研究了在假手术和新生期胸腺切除的LH大鼠中，胸腺刺激素（一种部分纯化的胸腺提取物）对血压的影响，并检查了胸腺切除的LH大鼠中主要血压调节神经内分泌因子是否发生变化。胸腺刺激素（1或10mg/kg/48小时）在假手术的LH大鼠中未改变血压，在新生期胸腺切除的动物中也未能持续升高血压。新生期胸腺切除未改变尿中盐皮质激素、儿茶酚胺及其代谢产物以及血浆肾素水平。在LH大鼠和正常血压对照中，新生期胸腺切除使血浆睾酮降低到相似程度。这些结果不支持胸腺激素因子在LH大鼠中具有升压作用，并表明新生期胸腺切除的降压作用并非继发于儿茶酚胺、肾素、盐皮质激素和睾酮分泌的减少。因此，它们提示胸腺在遗传性高血压LH大鼠中的作用更可能是由细胞免疫机制介导，而非激素过程。
