Substance P-induced oxygen consumption in rat major salivary glands

Abstract

Substance P (SP)-induced changes in oxygen consumption of rat subtnandibular, sublingual and parotid gland slices were investigated. SP elicited the concentration-dependent increase of oxygen consumption in all 3 glands. The increase was inhibit able by spamide II, the selective NK1 receptor antagonist, hut not by atropine, the muscarinic receptor antagonist. Respiratory effect of SP required the presence of Ca2+ in the incubation medium and was blocked by ouabain. SP had no significant effect on acetylcholine resting release from all 3 salivary glands. The study indicates that SP activates selective NK1 receptors, which are located only postsynaptically, and produces Ca2+-dependent and oubain-sensitive oxygen consumption in rat major salivary glands.