Peripheral haemodynamics after surgical reversal of two-kidney, one clip renal hypertension in rats.
The changes in peripheral haemodynamics and regional resistances were studied during the rapid fall in mean arterial pressure (MAP) after surgical reversal of two-kidney, one clip renal hypertension in rats (RHR). The controls used were sham-declipped RHR and normotensive control rats (NCR). During the 2 h following renal artery declipping or sham-operation, MAP and heart rate (HR) were followed continuously. Finally, the regional blood flows in the kidneys, small intestine and skeletal muscle were determined by the microsphere technique. Declipping caused MAP to fall from 167 +/- 5 to 108 +/- 5 mmHg (n = 10) with a concomitant fall in HR from 424 +/- 11 to 363 +/- 14 beats/min (P less than 0.01). The calculated vascular resistances fell in the intestinal and declipped renal vascular beds by 50-60% compared with sham-operated rats (P less than 0.01). However, vascular resistances remained unchanged in skeletal muscle and in the untouched kidney. This indicates that the reduction in flow resistance varies in the different vascular beds, presumably reflecting a mixture of suppressed sympathetic activity and direct vasodilatory actions induced by mechanisms activated upon reversal of two-kidney, one clip renal hypertension by renal artery declipping.
Göthberg
G
G
Nordlander
M
M
Lundgren
Y
Y
D000818:Animals; D001794:Blood Pressure; D006339:Heart Rate; D006978:Hypertension, Renovascular / Q000503:physiopathology* / Q000601:surgery; D007421:Intestine, Small / Q000098:blood supply; D008297:Male; D009132:Muscles / Q000098:blood supply; D051381:Rats; D011919:Rats, Inbred Strains; D012079:Renal Circulation; D013997:Time Factors; D014655:Vascular Resistance