Brasitus T A, Field M, Kimberg D V
Am J Physiol. 1976 Jul;231(1):275-82. doi: 10.1152/ajplegacy.1976.231.1.275.
Stimulation of alpha-adrenergic and muscarinic cholinergic receptors in rabbit ileal mucosa in vitro produced 5- to 15-fold increases in cyclic GMP (cGMP) concentration that were maximal within 2 min and gone within 30 min. Cholecystokinin octapeptide and insulin caused similar increases in cGMP. None of these agents affected cAMP. The epinephrine-induced increase in cGMP was blocked by atropine at 100 but not at 1 muM concentration. Epinephrine stimulates active NaCl absorption and decreases short-circuit current (SCC) in vitro, the latter effect due to inhibition of HCO3 secretion. Atropine (100 muM) blocked the former but not the latter effect of epinephrine. In vitro additions of several concentrations of cGMP and 8-bromo-cGMP did not decrease SCC or alter Na fluxes. Thus, changes in cGMP concentration have been directly correlated with changes in active absorption of NaCl, but a causal relationship has not been proven.
体外刺激兔回肠黏膜中的α-肾上腺素能受体和毒蕈碱型胆碱能受体会使环鸟苷酸（cGMP）浓度增加5至15倍，在2分钟内达到最大值，并在30分钟内消失。八肽胆囊收缩素和胰岛素也会使cGMP产生类似的增加。这些药剂均不影响环磷酸腺苷（cAMP）。肾上腺素诱导的cGMP增加在100μM但不是1μM浓度的阿托品作用下被阻断。肾上腺素在体外刺激主动氯化钠吸收并降低短路电流（SCC），后一种效应是由于抑制了碳酸氢根分泌。阿托品（100μM）阻断了肾上腺素的前一种效应，但未阻断后一种效应。体外添加几种浓度的cGMP和8-溴-cGMP不会降低SCC或改变钠通量。因此，cGMP浓度的变化与氯化钠主动吸收的变化直接相关，但因果关系尚未得到证实。
