Capponi A M, Vallotton M B
Circ Res. 1976 Aug;39(2):200-3. doi: 10.1161/01.res.39.2.200.
The role of sodium concentration, of alpha- and beta-adrenergic receptors, and of a microtubular inhibtor (vincristine) on renin release was studied in rat kidney slices in vitro. Renin release was an active, linear, and temperature-dependent process. Kidneys from young rats released much more renin than those from adults. Lowering sodium concentration inhibited renin release by one-half, even when osmolality was kept constant. Isoproterenol (10(-8) to 10(-5) M) stimulated renin release significantly in a partially dose-related manner. dl-propranolol inhibited this stimulation. Significant (P less than 0.05) inhibition of renin release was induced by l-epinephrine or l-norepinephrine (10(-5) M). In the presence of an alpha-receptor blocking drug, phenoxybenzamine (10(-5) M), inhibition no longer occurred with epinephrine and stimulation was observed with l-norepinephrine. Vincristine (10(-5) M) did not affect renin release when slices from the kidneys of normal rats or adrenalectomized, sodium-depleted rats were incubated, but significantly inhibited (P less than 0.01) release that had been stimulated in vitro by isoproterenol. These results suggest to us that there may be (1) a direct or indirect (mediated through the macula densa) effect of sodium on juxtaglomerular cells, (2) an inhibitory role for alpha-adrenergic receptors on renin release, in addition to the stimulatory role of beta-receptors, (3) possible participation of microtubules in isoproterenol-stimulated renin release, and (4) an alternative mode of secretion of renin under stimulation by adrenalectomy and salt depletion.
在体外对大鼠肾切片研究了钠浓度、α和β肾上腺素能受体以及一种微管抑制剂（长春新碱）对肾素释放的作用。肾素释放是一个活跃、呈线性且依赖温度的过程。幼鼠肾脏释放的肾素比成年鼠肾脏多得多。降低钠浓度可使肾素释放减少一半，即使渗透压保持恒定。异丙肾上腺素（10⁻⁸至10⁻⁵M）以部分剂量相关的方式显著刺激肾素释放。dl-普萘洛尔抑制这种刺激作用。L-肾上腺素或L-去甲肾上腺素（10⁻⁵M）可显著（P<0.05）抑制肾素释放。在存在α受体阻断药苯氧苄胺（10⁻⁵M）的情况下，肾上腺素不再产生抑制作用，而L-去甲肾上腺素则观察到刺激作用。当正常大鼠或肾上腺切除、缺钠大鼠的肾切片孵育时，长春新碱（10⁻⁵M）不影响肾素释放，但可显著（P<0.01）抑制体外异丙肾上腺素刺激的释放。这些结果向我们表明，可能存在：（1）钠对球旁细胞有直接或间接（通过致密斑介导）的作用；（2）除了β受体的刺激作用外，α肾上腺素能受体对肾素释放有抑制作用；（3）微管可能参与异丙肾上腺素刺激的肾素释放；（4）在肾上腺切除和缺盐刺激下肾素分泌的另一种模式。
