The hormone potentiating capability of amino acids on lactational performance in rats injected with 7,12-dimethylbenzanthracene (DMBA) during gestation.
DMBA administered to pregnant rats caused a significant decrease in mammary gland RNA and DNA contents on day 1 of lactation. Some amino acids had gonadotropic-like and/or estrogenic-like activity. In order to determine the effects of reproductive amino acids on DMBA primed mammary gland tissue, female adult virgin Long Evans rats (12 animals/group) were intraperitoneally injected daily with 1 mg DMBA in 0.2 ml sesame oil on days 8 through 12 of pregnancy. On days 8 through 17 of gestation these rats were subcutaneously injected with 150 mg/kg body weight of either L-tryptophan, L-arginine, or L-glycine in 1 ml saline solution. On day 1 of lactation L-tryptophan and L-glycine significantly increased the depressed DMBA control values for total RNA (mg), RNA (mg/100 g B.W.), RNA (mg/100 mg M.G.), RNA/DNA and the DNA (mg/100 g B.W.) to that of sesame oil controls. However, L-arginine had no stimulatory effect on the RNA or DNA values. The data suggests that L-glycine, which increases growth hormone release, and L-tryptophan, which enhances and mimicks prolactin secretion, negate the harmful effects of DMBA by stimulating mammary gland growth (i.e., DNA) and secretion (i.e., RNA).
D015127:9,10-Dimethyl-1,2-benzanthracene / Q000633:toxicity*; D000596:Amino Acids / Q000494:pharmacology*; D000818:Animals; D001120:Arginine / Q000494:pharmacology; D005260:Female; D005998:Glycine / Q000494:pharmacology; D006728:Hormones / Q000494:pharmacology*; D007774:Lactation / Q000187:drug effects*; D008321:Mammary Glands, Animal / Q000378:metabolism; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D011388:Prolactin / Q000494:pharmacology; D012313:RNA / Q000378:metabolism; D051381:Rats; D014364:Tryptophan / Q000494:pharmacology
D000596:Amino Acids; D006728:Hormones; D015127:9,10-Dimethyl-1,2-benzanthracene; D012313:RNA; D014364:Tryptophan; D011388:Prolactin; D001120:Arginine; D005998:Glycine