Inhibitory and contractile effects of okadaic acid on rat uterine muscle.
The effects of okadaic acid and its interactions with various agents known to increase, by different mechanisms, the intracellular levels of cyclic AMP and/or cyclic GMP were investigated in isolated strips of rat myometrium. Okadaic acid showed inhibitory effects at concentrations between 10(-7) M and 3 x 10(-6) M. At higher concentrations, a biphasic, contractile and then relaxant response was observed. The results obtained suggest that, in rat uterine smooth muscle, the inhibitory effects of okadaic acid are not entirely mediated by the activation of cyclic AMP- and/or cyclic GMP-dependent pathways. The data also point to the existence of a clear interaction between okadaic acid and methylxanthines, although further studies are needed to clarify the mechanisms involved in this interaction.
Candenas
M L
ML
Instituto Universitario de Bio-Orgánica, Universidad de La Laguna, Tenerife, Spain.
Norte
M
M
González
R
R
Arteche
E
E
Fernández
J J
JJ
Borges
R
R
Boada
J
J
Advenier
C
C
Martín
J D
JD
D000818:Animals; D000242:Cyclic AMP / Q000032:analysis*; D006152:Cyclic GMP / Q000032:analysis*; D004347:Drug Interactions; D004988:Ethers, Cyclic / Q000494:pharmacology*; D005260:Female; D066298:In Vitro Techniques; D019319:Okadaic Acid; D051381:Rats; D017207:Rats, Sprague-Dawley; D014590:Uterine Contraction / Q000187:drug effects*; D014599:Uterus / Q000187:drug effects; D014662:Vasoconstrictor Agents / Q000494:pharmacology*; D014970:Xanthines / Q000494:pharmacology
D004988:Ethers, Cyclic; D014662:Vasoconstrictor Agents; D014970:Xanthines; D019319:Okadaic Acid; C008514:methylxanthine; D000242:Cyclic AMP; D006152:Cyclic GMP