Morphine and dynorphin(1-13) microinjected into the medial preoptic area and nucleus accumbens: effects on sexual behavior in male rats.
The effects on sexual behavior of opiate receptor stimulation within A10 and A14 terminal areas were examined in the following experiments. Morphine (0.01-6 nmol) and dynorphin(1-13) (0.01-3 pmol) were microinjected into the medial preoptic area (MPOA). Morphine (10-100 pmol) and dynorphin (10-100 fmol) injected into the MPOA reduced both the latency to ejaculate and the number of intromissions triggering ejaculation. Morphine (6 nmol) produced a failure to resume copulating following the second ejaculation. Morphine (1-10 nmol) injected into the nucleus accumbens (ACC) shortened the latency to the first intromission and lengthened the second postejaculatory interval. Naloxone (3 mg/kg i.p.) reversed the effects of morphine on intromission latency and attenuated the lowering of ejaculatory threshold.
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Department of Psychology, State University of New York, Buffalo, Amherst 14260.
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D000818:Animals; D004399:Dynorphins / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D008845:Microinjections; D009020:Morphine / Q000008:administration & dosage / Q000494:pharmacology*; D009270:Naloxone / Q000494:pharmacology; D009294:Narcotics / Q000494:pharmacology; D009714:Nucleus Accumbens / Q000187:drug effects / Q000502:physiology*; D010446:Peptide Fragments / Q000008:administration & dosage / Q000494:pharmacology*; D011301:Preoptic Area / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D011957:Receptors, Opioid / Q000187:drug effects / Q000502:physiology; D012016:Reference Values; D012686:Septal Nuclei / Q000502:physiology*; D012726:Sexual Behavior, Animal / Q000187:drug effects*
D009294:Narcotics; D010446:Peptide Fragments; D011957:Receptors, Opioid; D009270:Naloxone; C026843:dynorphin (1-13); D004399:Dynorphins; D009020:Morphine