Regional blood flow in normotensive and spontaneously hypertensive rats.

Regional distribution of cardiac output in unanesthetized spontaneously hypertensive (SHR) and normotensive Wistar-Kyoto (WKY) and Wistar NR male rats (10 each group; average age 21 wk) was determined using two 15-mum microspheres (141Ce and 85Sr) injected 10 min apart through a left ventricular (LV) cannula. Fractional flow distribution was expressed as percentage activity of injected dose (average of the two measurements). Despite differences in body and organ weights, organ flow distribution did not vary between SHR and WKY, except for heart and testes (P less than 0.025). However, differences did not exist between SHR and NR with respect to heart, brain, lungs, spleen, and adrenal flows (P less than 0.05).