Some calcium and lysosome antagonists inhibit 3H-spiperone binding to the porcine anterior pituitary.
The dopamine antagonist 3H-spiperone binds to dopamine receptors in crude membrane preparations of the porcine anterior pituitary. In competition studies, several calcium channel antagonists (bepridil, D600 and verapamil) and a lysosomal enzyme inhibitor (chloroquine) displaced spiperone binding in a dose related manner. Because dopamine receptor activity modulates prolactin release from the anterior pituitary, it is suggested that the previously observed effects of some of these agents on prolactin release or storage may have been initiated at the level of the dopamine receptor or through physical modifications of the plasma membrane rather than the calcium channel or lysosome.
D000818:Animals; D001667:Binding, Competitive; D002090:Butyrophenones / Q000378:metabolism*; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D008247:Lysosomes / Q000187:drug effects*; D010903:Pituitary Gland, Anterior / Q000378:metabolism*; D013134:Spiperone / Q000378:metabolism*; D013552:Swine / Q000502:physiology*
D002090:Butyrophenones; D002121:Calcium Channel Blockers; D013134:Spiperone