Effect of thuringiensin on adenylate cyclase in rat cerebral cortex.
The purpose of this work is to evaluate the effect of thuringiensin on the adenylate cyclase activity in rat cerebral cortex. The cyclic adenosine 3'5'-monophosphate (cAMP) levels were shown to be dose-dependently elevated 17-450% or 54-377% by thuringiensin at concentrations of 10 microM-100 mM or 0.5-4 mM, due to the activation of basal adenylate cyclase activity of rat cerebral cortical membrane preparation. Thuringiensin also activated basal activity of a commercial adenylate cyclase from Escherichia coli. However, the forskolin-stimulated adenylate cyclase activity in rat cerebral cortex was inhibited by thuringiensin at concentrations of 1-100 microM, thus cAMP production decreased. Furthermore, thuringiensin or adenylate cyclase inhibitor (MDL-12330A) reduced the forskolin (10 microM)-stimulated adenylate cyclase activity at concentrations of 10 microM, 49% or 43% inhibition, respectively. In conclusion, this study demonstrated that thuringiensin could activate basal adenylate cyclase activity and increase cAMP concentrations in rat cerebral cortex or in a commercial adenylate cyclase. Comparing the dose-dependent effects of thuringiensin on the basal and forskolin-stimulated adenylate cyclase activity, thuringiensin can be regarded as a weak activator of adenylate cyclase or an inhibitor of forskolin-stimulated adenylate cyclase.
Tsai
San-Fu
SF
Laboratory of Toxicology and Pharmacology, Department of Veterinary Medicine, National Chung-Hsing University, Taichung, Taiwan, ROC.
Yang
Chi
C
Wang
Shun-Cheng
SC
Wang
Jiunn-Shiow
JS
Hwang
Jenn-Sheng
JS
Ho
Shu-Peng
SP
D000241:Adenosine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology*; D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D002540:Cerebral Cortex / Q000187:drug effects* / Q000201:enzymology*; D000242:Cyclic AMP / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation / Q000187:drug effects / Q000502:physiology; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D013400:Sugar Acids / Q000737:chemistry / Q000494:pharmacology*
D013400:Sugar Acids; D000242:Cyclic AMP; D000262:Adenylyl Cyclases; C068295:thuringiensin; D000241:Adenosine