ABSTRACT
Oxytetracydine elicited a dose dependant inhibitory effect on the twitch responses of the rabbit jujenum to perivascular stimulation and transmurally stimulated rat vas deferens. The inhibitory effect was investigated on field stimulated mouse vas deferens. Interactions at dopaminergic receptor sites, H2 Histaminic receptors, muscurinic cholinergic receptors, adrenoceptors and enhanced endogenous prostaglandin release were ruled out. Meanwhile, the inhibitory - response to the drug was ascribed via an interferences with external Ca2+ -availability. Oxytetracycline significantly enhanced the responses of the adrenoceptors to adrenaline. It was concluded that oxytetracyline evoked post-junctional supersensitivity in consequence of inhibition of adrenergic neurotransmission