ABSTRACT
<p><b>OBJECTIVE</b>To investigate the changes of the activity of both protein kinase A and C and the mechanisms of antipyretic action of Guizhi decoction.</p><p><b>METHOD</b>The fever responses were observed after combination injection of H-89 (a selective inhibitor of PKA) and calphostin C (a selective inhibitor of PKC), and oral pretreatment of Guizhi decoction in fever rats induced by an intra-cerebroventricular (icv) injection of an EP3 agonist, and both PKA and PKC activity in hypothalamus were measured in rats pretreated with Guizhi decoction and vehicle using isotopic tracing assay.</p><p><b>RESULT</b>The rise in rat body temperature was inhibited by H-89, Calphostin C, and Guizhi decoction, moreover, pretreatment with Guizhi decoction reduced PKA activity obviously. PKC activity in model rats exhibited a tendency to drop compared with that of control group, Oral administration of Guizhi decoction in large dose inhibited the response significantly, while the low dose of Guzhi decoction has no effect on PKC.</p><p><b>CONCLUSION</b>Both PKA and PKC may participate in the mechanism of fever induction by EP3 agonist. The decrease of PKA and PKC may contribute to the antipyretic action of Guizhi decoction, some isoenzyme of PKC may play a role in the fever production.</p>
Subject(s)
Animals , Male , Rats , Analgesics, Non-Narcotic , Pharmacology , Cinnamomum aromaticum , Chemistry , Cyclic AMP-Dependent Protein Kinases , Metabolism , Dinoprostone , Dose-Response Relationship, Drug , Drug Combinations , Drugs, Chinese Herbal , Pharmacology , Fever , Hypothalamus , Plants, Medicinal , Chemistry , Protein Kinase C , Metabolism , Random Allocation , Rats, Wistar , Receptors, Prostaglandin E , Receptors, Prostaglandin E, EP3 SubtypeABSTRACT
<p><b>OBJECTIVE</b>To investigate the effect of Guizhi Tang and its active components on the fever induced by EP3 receptor agonist sulprostone in rats.</p><p><b>METHOD</b>The rise in body temperature evoked by a LCV(lateral cerebroventricle)-injection of sulprostone was compared with that of sulprostone induced-fever rats pretreated with Guizgi Tang and its active compounds, cinnamaldehyde, cinnamic acid and total glucosides of paeony.</p><p><b>RESULT</b>Pretreatments with Guizhi Tang and cinnamaldehyde inhibited the rise in body temperature induced by sulprostone, while cinnamic acid tended to augment the fever. The sulprostone-induced fever was blocked by an ip pretreatment of total glucosides of paeony even below the basement.</p><p><b>CONCLUSION</b>Present data suggest that interruption with the down-stream events of EP3 receptor may contribute to the antipyretic action of Guizhi Tang, cinnamaldehyde and the total glucosides of paeony, while cinnamic acid may have no such effect.</p>