Effects of serotonin on circulation in the rat kidney

Abstract

The effects of serotonin upon the circulation of the rat kidney were studied by a modified benzidine staining technique and by the intravascular injection of India ink. A marked vasodilation with increased filling of the glomeruli and peritubular capillaries was noted 15 minutes after the injection of 10 mg/kg of serotonin reaching a maximum at 30 minutes. At 90 and 180 minutes there was a striking change in the cortical zone where the glomeruli appeared bloodless, while the circulation of the juxtamedullary areas remained unaltered. These studies indicate that serotonin in the doses used produced a shunting effect at the juxtamedullary area, although no cortical or tubular necrosis was demonstrable by hematoxylin and eosin stain. Reproduction of the same vascular pattern with intra-arterial India ink and the benzidine staining of the red blood cells support the concept that both red blood cells and plasma are shunted away from the cortex at the juxtamedullary area.