Opiate alkaloids and nitric oxide production in the nematode Ascaris suum.
The tissue distribution, course of secretion, and sex differences of morphine were delineated in Ascaris suum. Nitric oxide (NO) release in various tissues in response to morphine and its metabolite morphine-6-glucuronide (M6G) were also examined. Ascaris suum of both sexes along with their incubation fluid were analyzed for morphine concentrations by high-performance liquid chromatography (HPLC) over a 5-day period. Various tissues were also dissected for HPLC and NO analysis. Morphine was found to be most prevalent in the muscle tissue, and there is significantly more morphine in females than males, probably because of the large amounts present in the female uterus. Morphine (10(-9) M) and M6G (10(-9) M) stimulated the release of NO from muscles. Naloxone (10(-7) M) and N-nitro-L-arginine methyl ester (10(-6) M) blocked (P < 0.005) morphine-stimulated NO release from A. suum muscle tissue. D-Phe-Cys-Tyr-D-Trp-Om-Thr-Pen-Thr-NH2 (CTOP) (10(-7) M) did not block morphine's NO release. However, naloxone could not block M6G-stimulated NO release by muscles, whereas CTOP (10(-7) M) blocked its release. These findings were in seeming contradiction to our earlier inability to isolate a mu opiate receptor messenger RNA by reverse transcriptase-polymerase chain reaction using a human mu primer. This suggests that a novel mu opiate receptor was possibly present and selective toward M6G.
Zhu
Wei
W
State University of New York, Old Westbury Neuroscience Research Institute, P.O. Box 210, Old Westbury, New York 11568, USA.
Pryor
Stephen C
SC
Putnam
Jennifer
J
Cadet
Patrick
P
Stefano
George B
GB
D000818:Animals; D017165:Ascaris suum / Q000187:drug effects / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D008297:Male; D009020:Morphine / Q000037:antagonists & inhibitors / Q000378:metabolism*; D009022:Morphine Derivatives / Q000037:antagonists & inhibitors / Q000378:metabolism; D009132:Muscles / Q000378:metabolism; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009270:Naloxone / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D012727:Sex Characteristics; D013004:Somatostatin / Q000031:analogs & derivatives* / Q000494:pharmacology; D014018:Tissue Distribution
D004791:Enzyme Inhibitors; D009022:Morphine Derivatives; D009292:Narcotic Antagonists; C049352:phenylalanyl-cyclo(cysteinyltyrosyl-tryptophyl-ornithyl-threonyl-penicillamine)threoninamide; D009569:Nitric Oxide; D009270:Naloxone; D013004:Somatostatin; C035349:morphine-6-glucuronide; D009020:Morphine; D019001:Nitric Oxide Synthase; D019331:NG-Nitroarginine Methyl Ester