Inhibitory effects of arachidonic acid on muscarinic current response in single pancreatic acinar cells of rats.
AUTOR(ES)
Maruyama, Y
RESUMO
1. In single, enzymatically dissociated rat pancreatic acinar cells both acetylcholine (ACh) stimulation and IP3 (inositol 1,4,5-trisphosphate) injection evoke Ca2(+)-dependent transient responses. Exogenously applied arachidonic acid (AA) inhibits both responses in a dose-dependent manner. 2. Arachidonic acid oxidation inhibitors, indomethacin and nordihydroguaiaretic acid, cause no significant changes in ACh- and IP3-induced responses. The inhibitory effects of AA (50 microM) on IP3-induced responses are not influenced by the presence of these oxidation inhibitors. 3. An inhibitor of phospholipase A2 (PLA2), 4-bromophenacyl bromide (4-BPB; 10 microM), augments the ACh-induced response, and it potentiates the IP3-induced response by a factor of 10 to 20. The IP3-induced response, after its complete decay, is recovered by an administration of 4-BPB. 4. The results suggest that an increase in [Ca2+]i, induced by IP3 injection, activates PLA2, and that this resultant release of AA in turn inhibits IP3-dependent Ca2+ mobilization.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1181748Documentos Relacionados
- Activation and desensitization mechanisms of muscarinic current response in single pancreatic acinar cells of rats.
- Control of inositol polyphosphate-mediated calcium mobilization by arachidonic acid in pancreatic acinar cells of rats.
- Agonist-induced changes in cell membrane capacitance and conductance in dialysed pancreatic acinar cells of rats.
- Arachidonic acid facilitates experimental chronic osteomyelitis in rats.
- Dual effects of intracellular magnesium on muscarinic potassium channel current in single guinea-pig atrial cells.
