The properties and sensitivity to acetylcholine of PC12 cells differentiated with NGF / 中国应用生理学杂志

<p><b>AIM AND METHODS</b>The properties and sensitivity to acetylcholine of PC12 cells differentiated with nerve growth factor (NGF) have been investigated by using whole-cell clamp technique.</p><p><b>RESULTS</b>When cultured in the presence of NGF, PC12 cells not only differentiated to resemble sympathetic neurons morphologically, but also developed electrical excitability. NGF-treated PC12 cells were highly sensitive to ACh than untreated cells. The I(Ach) proved to be generated by nAChR by pharmacological identification. Nicotinic receptor was characterized by desensitization. The macroscopic I(ACh) was inward rectified and concentration dependent.</p><p><b>CONCLUSION</b>PC12 cells are easily cultured and provides a homogenous population of cells. When culture in NGF, they differentiate to sympathetic-like neurons that contain on their surface neuronal nAChR, it can be used as good model system for studying regulation of a sympathetic neuronal nAChR.</p>

Neomycin inhibits nicotinic receptor-mediated response in pheochromocytoma (PC12) cells / 生理学报

Neomycin is one of the aminoglycoside antibiotics, and on the cellular level it inhibits phospholipase C. The effects of neomycin on the acetylcholine (ACh)-induced current (I(ACh)) were studied in pheochromocytoma (PC12) cells by using the whole-cell clamp technique. The I(ACh) on PC12 cells proved to be generated through activation of the neuronal nicotinic receptor. ACh (30 micromol/L) induced an inward current at a holding potential of -80 mV. When the cells were applied with neomycin (0.01~1 mmol/L) and ACh (30 micromol/L) simultaneously, an inhibitory effect of neomycin on the peak of I(ACh) was observed. This effect was fast, reversible and concentration-dependent. Pretreatment with neomycin for 3~8 min had no influence on its inhibitory effect. Activation of protein kinase C by using an exogenous activator exerted an inhibitory action on I(ACh). However, intracellular dialysis with a PKC inhibitor (PKCI 19-31, 0.1~5 micromol/L) did not affect the inhibitory effect of neomycin. The results obtained suggest that neomycin exerts an inhibitory effect on I(ACh) without involvement of the blockage of phospholipase C.