title: The Accumulation of Diacylglycerol and Activation of Protein Kinase C by Caffeine Treatment in Frog Skeletal Muscle.
abstract: Our previous work has shown that high K(+) exposure could induce an accumulation of diacylglycerol (DAG) and the activation of protein kinase C (PKC) in frog skeletal muscle. To elucidate its mechanism, the effect of caffeine on the pathway of DAG/PKC signal transduction was investigated. Caffeine could induce DAG accumulation and PKC activation in a dose- and time-dependent manner. The accumulation of DAG induced by caffeine was significantly different from that produced by high K(+) exposure, although the intracellular calcium was raised to a similar peak. In addition, differences in the activation of PKC were shown between caffeine and high K(+) exposure. These differences suggest that the myoplasmic calcium increase produced by high K(+) exposure is not a sole factor for the activation of DAG/PKC signal transduction in frog skeletal muscle, and the high K(+)-induced depolarization may play some roles.
authors.affiliation: Shanghai Institute of Physiology, the Chinese Academy of Sciences, Shanghai 200031, China.
authors.forename: Jun-Hui
authors.initials: JH
authors.lastname: Sun
authors.forename: Pei-Hong
authors.initials: PH
authors.lastname: Zhu