8-OH-DPAT attenuates isoproterenol- but not forskolin-stimulated accumulation of cAMP in mediobasal hypothalamus

Ovariectomized female rats were used to test the possibility that the 5-HT1A receptor agonist, 8-hydroxy-2-(di-N-propylamino) tetralin (8-OH-DPAT), inhibits cyclic AMP (cAMP) accumulation in the mediobasal hypothalamus. Tissue slices were incubated with forskolin or with the β-adrenergic receptor agonist, isoproterenol, to stimulate accumulation of cAMP. Both compounds increased accumulation of cAMP. The 5-HT1A receptor agonist, 8-OH-DPAT, reduced cAMP accumulation after stimulation by isoproterenol, but not after forskolin stimulation. These findings are discussed in terms of putative differences in the mechanisms whereby 5-HT1A receptors are able to inhibit stimulation of adenylate cyclase. The potential significance of these findings to 5-HT1A receptor-mediated inhibition of female rat lordosis behavior is also discussed.