Role of cyclic adenosine 3',5'-monophosphate in the isoprenaline-induced relaxation of the oestrogen dominated rabbit uterus.
1. The role of cyclic adenosine 3',5'-monophosphate (cyclic AMP) in the relaxation produced by isoprenaline in muscle strips from the oestrogen dominated rabbit uterus has been investigated. 2. Isoprenaline 2 times 10- minus 8 M produced an inhibition of the mechanical activity but no increase in cyclic AMP. Isoprenaline 2 times 10- minus 6 M produced both inhibition of mechanical activity and increase in cyclic AMP. 3. The increase in cyclic AMP, but not the inhibition of mechanical activity, was blocked by propranolol 3.4 X 10-MINUS 6 M. 4. Dibutyryl-ccylic AMP produced a relaxation which mimicked that produced by isoprenaline, in that the longitudinal strips were more sensitive than the circular ones. 5. It is concluded that cyclic AMP may be a mediator of the beta-adrenergic effect in the oestrogen dominated rabbit myometrium. However, it seems not to be an obligatory link between stimulation of beta-adrenoceptors and relaxation. Other mechanisms may also exist.
D000818:Animals; D003994:Bucladesine / Q000494:pharmacology; D000242:Cyclic AMP / Q000378:metabolism*; D004967:Estrogens / Q000494:pharmacology*; D005260:Female; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology*; D010053:Ovary / Q000502:physiology; D011433:Propranolol / Q000494:pharmacology; D011506:Proteins / Q000378:metabolism; D051381:Rats; D013268:Stimulation, Chemical; D014599:Uterus / Q000378:metabolism* / Q000502:physiology
D004967:Estrogens; D011506:Proteins; D003994:Bucladesine; D011433:Propranolol; D000242:Cyclic AMP; D007545:Isoproterenol