Systemic and regional hemodynamics in cyclosporin A hypertension in the rat

This study examined the hemodynamic effects of 21 days oral administration of cyclosporin A (CyA) in the male Wistar rat. Forty rats were randomly div ided into four groups (n = 10). Group 1: Sham (olive oil 1 mL/kg/day by gav age) with cardiac output (CO) measurement. Group 2: CyA (CyA 15 mg/kg/day i n olive oil by gavage) with CO measurement. Group 3: Sham as for group 1 wi th regional flow measurements. Group 4: CyA as for group 2 with regional fl ow measurements. Systolic blood pressure was measured every fourth day. Aft er 21 days mean arterial blood pressure was measured by intra-arterial cann ulation, and CO, and renal, mesenteric, and hindquarter blood flows (RBE MB F, and HBF) were determined using transonic small animal flowmeters. Total peripheral resistance (TPR) and regional resistances were calculated. Oral CyA produced a sustained rise in systolic blood pressure. Olive oil did not affect blood pressure. CyA increased TPR (P < 0.05), renal vascular resist ance (RVR, P < 0.01) and MBF (P < 0.01), decreased RBF (P < 0.01), but did not change CO, HBE mesenteric or hindquarter vascular resistance. We conclu de that chronic oral administration of CBA produces hypertension with a hem odynamic profile characterized by rises in TPR and RVR without changes in C O or mesenteric or hindquarter vascular resistances in the Wistar rat.