Ginesi L M, Munday K A, Noble A R
J Physiol. 1983 Nov;344:453-63. doi: 10.1113/jphysiol.1983.sp014951.
Release of active and inactive renin by rabbit kidney cortex slices was investigated. Inactive renin was estimated as the increase in renin activity after acidification (pH 2.8) of slice supernatant solutions. In Ca2+-free media, release of both active and inactive renin was increased but the changes in inactive renin were more marked. The percentage of total renin released which was inactive ranged from 8.3% ([Ca2+] = 9.2 mM) to 34.5% (zero [Ca2+]) with a linear relationship (r = -0.96) over the range of [Ca2+] studied. Depolarizing media ([K+] = 20 mM) suppressed release of inactive renin more than release of the active form. This effect, for both forms of renin, was lost when Ca2+ ions were omitted from the incubation media. This suggests that influx of Ca2+ ions was responsible for the reduced renin secretion following depolarization of the juxtaglomerular cells. Reducing the [K+] of the incubation buffer from 5.7 mM (control) to 1.0 mM did not alter active renin but increased release of inactive renin. Low [K+] media abolished the stimulatory effect of low [Ca2+] on release of both forms of renin. In incubation media with low [Ca2+] or with low [K+] the mixture of renins released by the kidney cortex slices correlated with that found in extracts of non-incubated kidney: that is, about 35% of the total renin was in the inactive form. Mechanisms controlling the secretion of active and inactive renins by the kidney are at least partially independent. Differential secretion of the two forms, perhaps linked to regulation of the activation of inactive renin before release, appears to be the basis of a control step in the over-all expression of the renin-angiotensin system. This may be coupled in some way to juxtaglomerular cell Na+ ion flux.
对兔肾皮质切片中活性肾素和非活性肾素的释放进行了研究。非活性肾素通过切片上清液酸化（pH 2.8）后肾素活性的增加来估算。在无Ca2+的培养基中，活性肾素和非活性肾素的释放均增加，但非活性肾素的变化更为明显。在所研究的Ca2+浓度范围内，释放的总肾素中非活性肾素的百分比范围为8.3%（[Ca2+]=9.2 mM）至34.5%（零[Ca2+]），呈线性关系（r = -0.96）。去极化培养基（[K+]=20 mM）对非活性肾素释放的抑制作用比对活性形式的抑制作用更强。当孵育培养基中省略Ca2+离子时，两种形式肾素的这种作用均消失。这表明Ca2+离子的内流是球旁细胞去极化后肾素分泌减少的原因。将孵育缓冲液的[K+]从5.7 mM（对照）降至1.0 mM不会改变活性肾素，但会增加非活性肾素的释放。低[K+]培养基消除了低[Ca2+]对两种形式肾素释放的刺激作用。在低[Ca2+]或低[K+]的孵育培养基中，肾皮质切片释放的肾素混合物与未孵育肾脏提取物中的肾素混合物相关：即，总肾素中约35%为非活性形式。肾脏控制活性和非活性肾素分泌的机制至少部分是独立的。两种形式的差异分泌，可能与释放前非活性肾素激活的调节有关，似乎是肾素-血管紧张素系统整体表达中一个控制步骤的基础。这可能在某种程度上与球旁细胞Na+离子通量相关。
