Muirhead E E, Pitcock J A, Nasjletti A, Brown P, Brooks B
Hypertension. 1985 May-Jun;7(3 Pt 2):I127-35. doi: 10.1161/01.hyp.7.3_pt_2.i127.
Unclipping the one-kidney, one-clip hypertensive rat during a free flow of urine caused the blood pressure to return to normal levels within about 3 hours. We found that administration of captopril plus unclipping caused the blood pressure to return to normal in minutes (17 +/- 4). Ureterocaval anastomosis plus captopril plus unclipping also caused the blood pressure to return to normal in minutes (8.8 +/- 2). Thus, the potentiation of the drop in blood pressure does not seem to be due to a volume effect. Administration of indomethacin and aprotinin did not prevent a rapid decline of the blood pressure after unclipping, but the decline was less rapid than that occurring after captopril and unclipping, which suggests that prostaglandin may have some effect on this mechanism. Saralasin administration did not potentiate the antihypertensive action of captopril plus unclipping. Chemical papillectomy prevented the drop in blood pressure after unclipping. The bolus dose of captopril to the hypertensive rat often caused a transient depressor effect resembling that due to the antihypertensive neutral renomedullary lipid, which suggests secretion of this lipid into the blood. The renomedullary interstitial cells accumulated large lipid granules after captopril administration. These cells also degranulated after unclipping. These findings are consistent with the hypothesis that the renal papilla secretes an antihypertensive hormone after unclipping. At present, antihypertensive neutral renomedullary lipid is the main putative hormone.
在自由排尿过程中解除单肾单夹高血压大鼠的夹闭，血压在约3小时内恢复至正常水平。我们发现，给予卡托普利并解除夹闭可使血压在数分钟内（17±4）恢复正常。输尿管腔静脉吻合术联合卡托普利并解除夹闭也可使血压在数分钟内（8.8±2）恢复正常。因此，血压下降的增强似乎并非由于容量效应。给予吲哚美辛和抑肽酶并不能阻止解除夹闭后血压的快速下降，但下降速度比卡托普利与解除夹闭后要慢，这表明前列腺素可能对该机制有一定作用。给予沙拉新并不能增强卡托普利与解除夹闭的降压作用。化学性肾乳头切除可防止解除夹闭后血压下降。给高血压大鼠静脉注射大剂量卡托普利常引起短暂的降压效应，类似于抗高血压中性肾髓质脂质所致的效应，这提示该脂质分泌入血。给予卡托普利后，肾髓质间质细胞积累了大量脂质颗粒。解除夹闭后这些细胞也出现脱颗粒现象。这些发现与肾乳头在解除夹闭后分泌一种降压激素的假说相符。目前，抗高血压中性肾髓质脂质是主要的假定激素。
