Detection of serum autoantibodies against AT₁A-receptor during the development of the four types of hypertensive rat models / 生理学报

Using two-kidney one-clip renal hypertensive (2K1C group), stress-induced hypertensive (neural group), DOCA-salt treated hypertensive (DOCA group) and spontaneously hypertensive rats (SHR group), to investigate the change in AT(1A)-receptor autoantibodies (AT(1A)-AAs) during the development of the four types of hypertension. The biological activities of AT(1A)-AAs were examined. It was shown that the frequency of occurrence and titres of AT(1A)-AAs increased significantly during the development of hypertension. In the four hypertensive groups studied, the occurrence of AT(1A)-AAs was most prominent in SHR, 2K1C and neural groups. The biological effects of AT(1A)-AAs were shown to increase the beating frequency of cultured neonatal myocardial and vascular contractile tension. It is suggested that autoimmune mechanisms are involved the pathogenesis of different types of hypertension and the AT(1A)-AAs may be one of the mechanisms leading to cardiac hypertrophy.

Comparative studies of vasodilating effects of angiotensin-(1-7) on the different vessels / 生理学报

The purpose of this study was to compare the vasodilating effects of angiotensin-(1-7) [Ang-(1-7)] on the different vessels and to clarify its mechanisms by using relaxing responses of preconstricted vascular rings. The results showed: (1) Ang-(1-7) dose-dependently induced vasorelaxation in all the vessels studied. However, there is apparent heterogeneity in the responsiveness of vessels from different origin. (2) The Ang-(1-7)-induced vasorelaxation was endothelium dependent and largely mediated by NO system. (3) The vasodilator action of Ang-(1-7) was not mediated by AT1 or AT2 receptor subtypes. It is suggested that the Ang-(1-7)-induced vasorelaxation is endothelium dependent by some other unclarified angiotensin receptor subtypes and is largely mediated by NO system.