Kohzuki M, Hodsman G P, Johnston C I
Melbourne University Department of Medicine, Austin Hospital, Heidelberg, Victoria, Australia.
Am J Physiol. 1989 Feb;256(2 Pt 2):H533-8. doi: 10.1152/ajpheart.1989.256.2.H533.
The natriuretic, diuretic, and hypotensive effects of atrial natriuretic peptide (ANP) were examined in rats 4 wk after myocardial infarction induced by left coronary artery ligation. Synthetic rat ANP (fragment 1-28) was infused intravenously in doses of 0.1, 0.3, and 1.0 micrograms.kg-1.min-1 for 30 min. There was a significant decrease in systolic blood pressure in controls and rats with infarction, although only in control rats was there a significant decrease in diastolic blood pressure. Changes in systolic and diastolic blood pressure were attenuated in rats with infarction compared with controls (P less than 0.01). The diuretic and natriuretic effects of ANP were observed in both groups of rats, but the effects were significantly less in rats with infarction (P less than 0.01). The ANP infusion did not induce significant changes in heart rate or hematocrit in controls or rats with infarction. The results indicate that rats with chronic left heart failure are less sensitive to the natriuretic, diuretic, and hypotensive effects of ANP when compared with controls. The attenuated renal response to ANP may contribute to the impaired sodium and water excretion in chronic heart failure, although other mechanisms are involved.
在通过左冠状动脉结扎诱导心肌梗死4周后的大鼠中，研究了心房利钠肽（ANP）的利钠、利尿和降压作用。以0.1、0.3和1.0微克·千克⁻¹·分钟⁻¹的剂量静脉输注合成大鼠ANP（片段1 - 28），持续30分钟。对照组和梗死大鼠的收缩压均显著降低，不过只有对照组的舒张压有显著降低。与对照组相比，梗死大鼠的收缩压和舒张压变化减弱（P < 0.01）。两组大鼠均观察到ANP的利尿和利钠作用，但梗死大鼠的这些作用显著较小（P < 0.01）。ANP输注在对照组或梗死大鼠中均未引起心率或血细胞比容的显著变化。结果表明，与对照组相比，慢性左心衰竭大鼠对ANP的利钠、利尿和降压作用较不敏感。尽管涉及其他机制，但肾脏对ANP反应的减弱可能导致慢性心力衰竭中钠和水排泄受损。
