Systemic and regional hemodynamics in cyclosporin A hypertension in the rat

SUMMARY: This study examined the hemodynamic effects of 21 days oral administration of cyclosporin A (CyA) in the male Wistar rat. Forty rats were randomly divided into four groups (n=10). Group 1: Sham (olive oil 1 mL/kg/day by gavage) with cardiac output (CO) measurement. Group 2: CyA (CyA 15 mg/kg/day in olive oil by gavage) with CO measurement. Group 3: Sham as for group 1 with regional flow measurements. Group 4: CyA as for group 2 with regional flow measurements. Systolic blood pressure was measured every fourth day. After 21 days mean arterial blood pressure was measured by intra‐arterial cannulation, and CO, and renal, mesenteric, and hindquarter blood flows (RBF, MBF, 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 resistance (RVR, P<0.01) and MBF (P<0.01), decreased RBF (P<0.01), but did not change CO, HBF, mesenteric or hindquarter vascular resistance. We conclude that chronic oral administration of CyA produces hypertension with a hemodynamic profile characterized by rises in TPR and RVR without changes in CO or mesenteric or hindquarter vascular resistances in the Wistar rat.