心房钠尿因子对麻醉家兔局部血流的影响

在42只麻醉家兔,观察了静脉注射心房肽Ⅱ(AtriopeptinⅡ,APⅡ)对局部血流量以及动脉内注射 AP Ⅱ 对局部血管阻力的影响。结果如下:(1)静脉注射 APⅡ(30μg/kg)5min后,平均动脉压(MAP)降低11.0±1.5mmHg(n=8,M±SE,下同),与溶剂对照组相比有明显差异(P

EFFECTS OF ATRIAL NATRIURETIC FACTOR ON REGIONAL BLOOD FLOW IN ANESTHETIZED RABBIT

The regional blood flow changes induced by intravenous injection of atriopeptin III (AP III) and the effects of intra-arterial injection of AP III on regional vascular resistance were investigated in 42 anesthetized rabbits. The results were as follows: (1) In anesthetized rabbits (n = 8), intravenous injection of AP III (30 micrograms/kg) resulted in a decrease in mean arterial pressure by 11.0 +/- 1.5 mmHg (M +/- SE, P less than 0.01), while the heart rate showed no change. (2) By using the isotopic biomicrosphere method, it was revealed that AP III increased the blood flow in renal cortex (P less than 0.05) and decreased the blood flow in renal medulla. However, the blood flow in brain, heart, intestine, and hindlimb muscle remained unchanged. (3) With the constant autoperfusion method, renal intra-arterial administration of AP III (0.8 micrograms/kg) decreased the mean renal perfusing pressure by 21.2 +/- 3.3 mmHg (n = 9, P less than 0.001). By injecting AP III into the femoral artery, the mean perfusing pressure of hindlimb lowered by 7.8 +/- 1.1 mmHg (n = 7, P less than 0.001). No change occurred in the perfusing pressure of mesenteric vascular bed following intraarterial injection of AP III. The results showed that AP III dilated the renal artery and thereby increased the renal blood flow. The vasodilating effect of AP III appeared to be more prominent in renal vascular bed than that in the other vascular beds. The increase in renal blood flow induced by AP III may be one of the mechanisms diuretic and natriuretic actions.