Kashiwayanagi M, Kawahara H, Kurihara K
Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan.
J Physiol Paris. 1994;88(5):309-14. doi: 10.1016/0928-4257(94)90011-6.
Olfactory responses appear not only at the onset of odor stimulation, but also at the termination of the stimulation. It is widely considered that the cAMP-pathway is involved in the generation of odor responses. We examined how cAMP affects the generation of off-responses. To explore the role of the cAMP-pathway, odorants were applied to the turtle olfactory epithelium after forskolin at high concentrations which saturated the olfactory response to forskolin. Various odorants induced off-responses after 50 microM forskolin, indicating that off-responses are not induced via the cAMP-dependent pathway. However, the magnitude of the off-response after forskolin varied from 100 to 1400% of those of off-responses in its absence, indicating that forskolin greatly enhanced the off-responses to some odorants. The off-response after 0.1 mM citralva was also enhanced by 3 mM 8-(4-chlorophenylthio)-adenosine 3',5'-cyclic monophosphate (cpt-cAMP). These results suggested that cAMP modulates off-responses in the turtle olfactory system.
嗅觉反应不仅出现在气味刺激开始时，也出现在刺激终止时。人们普遍认为cAMP信号通路参与了气味反应的产生。我们研究了cAMP如何影响关闭反应的产生。为了探究cAMP信号通路的作用，在高浓度福司可林使嗅觉对福司可林的反应饱和后，将气味剂施加到龟的嗅觉上皮。在50微摩尔福司可林作用后，各种气味剂诱导出关闭反应，这表明关闭反应不是通过cAMP依赖性途径诱导的。然而，福司可林作用后的关闭反应幅度在无福司可林时关闭反应幅度的100%至1400%之间变化，这表明福司可林极大地增强了对某些气味剂的关闭反应。0.1毫摩尔柠檬醛作用后的关闭反应也被3毫摩尔8 -（4 -氯苯硫基）-腺苷3'，5'-环磷酸（cpt - cAMP）增强。这些结果表明cAMP调节龟嗅觉系统中的关闭反应。
