- 作者: 吳劍男; 黃萬出
- 作者服務機構: 國防醫學院生理及生物物理學科
- 中文摘要:
以往的實驗報告指出心房利鈉排泄因子可抑制腎素的分泌,而血管張力素轉化?抑制劑cilazapril可阻斷乙型血管張
力素的生成。因為這兩種物質皆能增加腎臟的排泄功能,所以本實驗旨在探討由心房利鈉排泄因子所產生之腎功能增強
是否肇因於腎素-血管張力素系統之抑制。實驗時在正常鼠麻醉情況下,單一靜注2.5μg/kg之心房利鈉徘泄因子降低
平均動脈血壓6.8±2.3%,靜注5 0μg/kg則降低血壓9.4±2.2%。注射2.5μg/kg之心房利鈉排泄因子,使腎小球濾過
率增加5.6±3.7%、鈉離子排泄量增加55.0±18.5%、尿流量增加24.8±9.3%。注射5.0μg/kg之心房利鈉排泄因子則分
別使腎小球濾過率增加8.4±2.8%、鈉離子排泄量增加105.2±39.9%、尿流量增加35.6±14.6%。持續以33μg/kg.min
之劑量靜脈灌注cilazapril會使血壓降低,而腎小球濾過率及鈉和水排泄率則增加。在灌注cilazapril期間,給予前述兩種
不同劑量之心房利鈉排泄因子,分別使血壓再下降8.3±1.9%及10.9±5.4%,但是腎臟排泄功能則無顯著改變,後者與
cilazapril引起之血壓下降無關。上述結果顯示心房利鈉排泄因子增強腎臟排泄功能與內生性乙型血管張力素有關,而其
降血壓之作用則否。c - 英文摘要: Previous studies have shown that atrial natriuretic factor (ANF) inhibits renin secretion whereascilazapril blocks angiotensin II generation via converting enzyme inhibition. Both agents enhance renalexcretory function. The present study was conducted to test whether the renin-angiotension system isinvolved in the ANF-induced renal effects. ANF was administered to anesthetized normal rats (n=16)with or without a simultaneous infusion of cilazapril. Single bolus injections of ANF at doses of 2.5 μg/kgand 5.0 μg/kg significantly decreased mean arterial blood pressure by 6.8±2.3% and 9.4±2.2%, respectively.The corresponding increases in glomerular filtration rate were 5.6±3.7% and 8.4±2.8%, in absolute sodiumexcretion were 55.0±18.5% and 105.2±39.9%, and in urine flow were 24.8±9.3% and 35.6±14.6%. In-travenous infusion of cilazapril (33μg/kg·min) reduced the arterial blood pressure, elevated the glomerularfiltration rate and increased sodium and water excretion. The corresponding doses of ANF administrationduring continuous infusion of cilazapril further decreased blood pressure by 8.3±1.9% and 10.9±5.4%,respectively. However, there were no significant changes in the glomerular filtration rate and sodium andwater excretion. The failure of ANF to exhibit a renal effect was irrevalent to the lowering blood pressureinduced by cilazapril. These results suggest that reduced endogenous angiotensin II generation contributesto the renal, but not the hypotensive, effect of ANF.
- 中文關鍵字: glomerular filtration rate; natriuresis; diuresis; atrial natriuretic factor cilazapril
- 英文關鍵字: --