title: Effect of oral contraceptives and vitamin B6 supplements on alanine and glycine metabolism.
abstract: Plasma alanine or glycine concentrations and blood pyruvate were studied before and after oral administration of the two amino acids to women using estrogen-containing oral contraceptives and to a control group of women. Thirty oral contraceptive users and 14 controls received alanine loads (200 mg/kg of body weight). The two groups had similar fasting plasma alanine levels, but the fasting blood pyruvate was elevated in the contraceptive steroid-treated women. After alanine ingestion, the increases in plasma alanine were significantly lower in the oral contraceptive users. Both groups showed a rise in blood pyruvate; there were no differences in the increments above fasting values. Treatment with pyridoxine hydrochloride, 25 mg for 4 weeks, had not effect on the responses of 11 oral contraceptive users to alanine loading. Twenty-four oral contraceptive users and 14 controls were studied before and after a glycine load (140 mg/kg of body weight). The fasting plasma glycine levels were similar, but lesser increases after ingestion of the amino acid occurred in the oral contraceptive-treated group. Blood pyruvate concentrations in both oral contraceptive users and controls were unaffected by oral glycine loads.
mesh_terms: D000328:Adult; D000409:Alanine / Q000378:metabolism*; D003276:Contraceptives, Oral / Q000494:pharmacology*; D003277:Contraceptives, Oral, Combined / Q000494:pharmacology; D003280:Contraceptives, Oral, Synthetic / Q000494:pharmacology*; D005260:Female; D005998:Glycine / Q000378:metabolism*; D006801:Humans; D011736:Pyridoxine / Q000494:pharmacology*; D011773:Pyruvates / Q000097:blood; D013997:Time Factors
chemical_list: D003276:Contraceptives, Oral; D003277:Contraceptives, Oral, Combined; D003280:Contraceptives, Oral, Synthetic; D011773:Pyruvates; D011736:Pyridoxine; D000409:Alanine; D005998:Glycine