Different effects of current strength on inhibitory responses of the mouse vas deferens to methionine- and leucine-enkephalin.
The inhibitory potency of methionine (Met)-enkephalin on the field-stimulated mouse vas deferens was greatly increased by a reduction in current strength whilst that of leucine (Leu)-enkephalin increased only slightly. All currents were submaximal and all muscle twitches were neuronally evoked. These results suggest that inhibitory effects of Met- and Leu-enkephalin in the mouse vas deferens are not commonly mediated and provide a rapid method for ascertaining heterogeneity of enkephalin extracts.
D000818:Animals; D004558:Electric Stimulation; D004723:Endorphins / Q000494:pharmacology*; D004745:Enkephalins / Q000494:pharmacology*; D007082:Ileum / Q000502:physiology; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects*; D014649:Vas Deferens / Q000502:physiology
D004723:Endorphins; D004745:Enkephalins