AJP - Gastrointestinal and Liver Physiology, Vol 253, Issue 2 146-G154, Copyright © 1987 by American Physiological Society
Splanchnic circulatory changes during development of renal hypertension
G. A. Meininger, J. N. Benoit, E. Z. Ostrowska and S. K. Muckleroy
Total and regional splanchnic blood flows were measured with radiolabeled
microspheres (15 micron) in one-kidney, one-clip renal hypertensive rats at
2, 4, and 6 wk after induction of hypertension. Arterial pressures (mean
+/- SE, mmHg) for the normotensive rats (N) and age-matched hypertensive
rats (H) were 110 +/- 5 and 114 +/- 6 at 2 wk, 104 +/- 4 and 148 +/- 13 at
4 wk, and 117 +/- 6 and 164 +/- 11 at 6 wk, respectively. Total splanchnic
blood flow was increased in H compared with N at 4 wk but not at 2 or 6 wk.
The blood flow changes among individual splanchnic organs varied in N and
H. For example, at 2 and 4 wk, stomach, small intestine, large intestine,
pancreas, hepatic artery, and portal venous blood flows in H were unchanged
compared with N. At 6 wk, small intestinal and hepatic arterial blood flows
were increased in H compared with N, and pancreatic blood flow was
decreased. Vascular resistance was not different for any splanchnic organs
between N and H at 2 wk, but it was elevated in H for all organs at 4 and 6
wk except for the hepatic artery. In another group of rats, the renal and
superior mesenteric arteries (SMA) were instrumented with ultrasonic
Doppler flow probes. Acute one-kidney, one-clip hypertension was produced
by removing one kidney and mechanically reducing flow to the remaining
kidney with a pneumatic occluder. After 2 h of stenosis, mean arterial
pressure and SMA flow velocity was decreased by 6%.(ABSTRACT TRUNCATED AT
250 WORDS)
