Kurokawa K, Lenchner G, Massry S G
Nephron. 1977;18(1):60-7. doi: 10.1159/000180767.
Parathyroid hormone (PTH) and catecholamines (CA) increased cAMP levels in isolated tubules of rat renal cortex. A rise in cAMP could be detected 10 sec after the addition of agonists, and it reached the peak in 30-60 sec and then decreased despite the presence of active agonists. Direct relationships exist between theophylline concentrations and cAMP levels in response to agonists. Three- to fivefold rises in cAMP levels were observed with a maximal dose of PTH compared with that of CA, and there was no additive effect. Both PTH and CA stimulated renal gluconeogenesis; when added together with each maximal dose, no additive effect was observed. These results suggest the important role of phosphodiesterase to control tubular cAMP in response to hormonal stimuli, and there is a tubule cell group responding to both PTH and CA.
甲状旁腺激素（PTH）和儿茶酚胺（CA）可提高大鼠肾皮质离体肾小管中的环磷酸腺苷（cAMP）水平。加入激动剂10秒后即可检测到cAMP升高，30 - 60秒达到峰值，随后即便存在活性激动剂，cAMP水平仍会下降。茶碱浓度与激动剂刺激下的cAMP水平之间存在直接关系。与CA相比，PTH最大剂量时可使cAMP水平升高3至5倍，且无相加效应。PTH和CA均刺激肾糖异生；当二者同时加入最大剂量时，未观察到相加效应。这些结果表明磷酸二酯酶在控制激素刺激下肾小管cAMP方面具有重要作用，且存在一组对PTH和CA均有反应的肾小管细胞。
