[Dopaminergic effect of anisodamine on the microcirculation of the hydronephrotic kidney of rats].

Anisodamine is an alkaloid extracted from the Tibetan plant "Anisodus tanguticus". Since 1965 it has been used in China for the treatment of shock but the mechanisms of its action are not fully known. The present study was performed to determine the effect of anisodamine on the renal microcirculation and to examine the underlying mechanism of its actions. The addition of anisodamine (10(-8) M to 10(-3) M) to the kidney bath resulted in a significant and dose dependent dilation of all preglomerular vessels. The maximal dilation (about 30% dilation) was found in the proximal interlobular artery. In contrast to preglomerular vessels anisodamine caused constriction of postglomerular vessels. The glomerular blood flow increased by about 50% at anisodamine concentration of 10(-3) M. Haloperidol, a dopamine receptor antagonist could abolish the renal vascular effect of anisodamine. It is suggested that anisodamine could improve renal function by the dilation of preglomerular vessels in combination with the constriction of postglomerular vessels, and the effect of anisodamine may be mediated by activation of the dopaminergic system.