Evidence for morphine and morphine-like alkaloid responses resistant to naloxone blockade in the rat vas deferens.
D000818:Animals; D004361:Drug Tolerance; D004558:Electric Stimulation; D004745:Enkephalins / Q000494:pharmacology; D066298:In Vitro Techniques; D007930:Leucine / Q000494:pharmacology; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D009022:Morphine Derivatives / Q000494:pharmacology; D009119:Muscle Contraction / Q000187:drug effects; D009270:Naloxone / Q000494:pharmacology*; D009294:Narcotics / Q000494:pharmacology; D010919:Placebos; D051381:Rats; D011957:Receptors, Opioid / Q000378:metabolism; D014649:Vas Deferens / Q000187:drug effects* / Q000502:physiology
D004745:Enkephalins; D009022:Morphine Derivatives; D009294:Narcotics; D010919:Placebos; D011957:Receptors, Opioid; D009270:Naloxone; D009020:Morphine; D007930:Leucine