title: Decreased enkephalinase activity following postnatal treatment with phenobarbital.
abstract: The effect of postnatal administration of phenobarbital on enzymes degrading enkephalin was examined. Daily subcutaneous injections (45 mg/kg) of phenobarbital were given to male and female rats from postnatal day 1 to 19. Brains from rats treated with saline and phenobarbital were used to prepare aminopeptidases (high speed supernatant) and enkephalinase A (synaptosomal membrane preparation). Incubation of methionine enkephaline (ME) with aminopeptidases from rat brain liberated tyrosine (T), while incubating with enkephalinase A resulted in the formation of tyrosylglycylglycin (TGG). Separation and quantification of tyrosine, tyrosylglycylglycin and methionine enkephalin was performed using a high performance liquid chromatograph, coupled to electrochemical and ultraviolet detectors in series. The treatment of the rats with phenobarbital resulted in a significant inhibition of enkephalinase A when measured in vitro, using methionine enkephalin as substrate. Preliminary studies with secobarbital show similar results to those obtained with phenobarbital.
mesh_terms: D000626:Aminopeptidases / Q000378:metabolism; D000818:Animals; D000831:Animals, Newborn; D001921:Brain / Q000201:enzymology* / Q000378:metabolism; D010450:Endopeptidases / Q000378:metabolism*; D004744:Enkephalin, Methionine / Q000378:metabolism; D005260:Female; D008297:Male; D015260:Neprilysin; D010634:Phenobarbital / Q000097:blood / Q000494:pharmacology*; D011480:Protease Inhibitors; D051381:Rats; D011919:Rats, Inbred Strains; D012631:Secobarbital / Q000097:blood / Q000494:pharmacology
chemical_list: D011480:Protease Inhibitors; D012631:Secobarbital; D004744:Enkephalin, Methionine; D010450:Endopeptidases; D000626:Aminopeptidases; D015260:Neprilysin; D010634:Phenobarbital