Hofbauer K G, Konrads A, Schwarz K, Werner U
Klin Wochenschr. 1978;56 Suppl 1:51-9. doi: 10.1007/BF01477453.
The role of cyclic AMP in the regulation of renin release (RR) was studied in isolated rat kidneys, which were perfused at constant pressure in a single-pass system with a modified Krebs-henseleit solution. Isoproterenol (IP) (2 x 10(-9) to 2 x 10(-6) M) and 3-isobutyl-1-methyl-xanthine (IBMX) (4 x 10(-7) to 7 x 10(-5) M) induced a dose-dependent increase of renal perfusate flow, glomerular filtration rate and urinary sodium excretion. RR was stimulated up to 10-fold above control values within 5 min. At the lowest concentrations IP stimulated RR, but did not affect renal haemodynamics. When IP and IBMX were administered concomitantly, a supraadditive stimulation of RR was observed. Dibutyryl-cAMP (db-cAMP) and 8-Br-cGMP (10(-6) to 10(-4) M) produced a similar dose-dependent vasodilation and natriuresis, but differed in their action on RR. Within 15 min after the start of the infusion, db-cAMP increased RR up to 4-fold, whereas 8-Br-cGMP was without an effect. These results suggest that IP, IBMX and db-cAMP stimulated RR by increasing the concentrations of cAMP in the epitheloid cells and independently of changes in renal haemodynamics and sodium excretion.
在离体大鼠肾脏中研究了环磷酸腺苷（cAMP）在肾素释放（RR）调节中的作用。这些肾脏在单通道系统中以恒定压力用改良的克雷布斯-亨塞尔特溶液灌注。异丙肾上腺素（IP）（2×10⁻⁹至2×10⁻⁶M）和3-异丁基-1-甲基黄嘌呤（IBMX）（4×10⁻⁷至7×10⁻⁵M）诱导肾灌注液流量、肾小球滤过率和尿钠排泄呈剂量依赖性增加。RR在5分钟内被刺激至比对照值高10倍。在最低浓度时，IP刺激RR，但不影响肾脏血流动力学。当同时给予IP和IBMX时，观察到RR有超相加刺激作用。二丁酰-cAMP（db-cAMP）和8-溴-cGMP（10⁻⁶至10⁻⁴M）产生类似的剂量依赖性血管舒张和利钠作用，但它们对RR的作用不同。在输注开始后15分钟内，db-cAMP使RR增加至4倍，而8-溴-cGMP无作用。这些结果表明，IP、IBMX和db-cAMP通过增加上皮样细胞中cAMP的浓度来刺激RR，且与肾脏血流动力学和钠排泄的变化无关。
