Luteinizing hormone and growth hormone concentrations in serum of prepubertal gilts treated with N-methyl-D,L-aspartate.
Prepubertal Yorkshire gilts, 189 d of age and 96 kg body weight (BW), were used to determine the effects of intravenous injections of N-methyl-D,L-aspartate (NMA) on circulating concentrations of luteinizing hormone (LH) and growth hormone (GH). In Experiment 1, blood was sampled from four gilts every 15 min for 2 hr on four consecutive days. One hour after the initiation of sampling on each day, gilts received either vehicle (0.9% saline solution) or 1.25, 2.5, or 5 mg of NMA/kg BW as per a 4 x 4 latin square arrangement of treatments. There was no effect of treatment (P > 0.1) on concentrations of LH in serum. However, relative to vehicle-treated animals, gilts administered 2.5 mg of NMA/kg BW had elevated (1,120%; P < 0.05) circulating levels of GH. In Experiment 2, samples were collected from 15 gilts at 15-min intervals for 1 hr before and 1 hr after NMA (10 mg/kg BW; n = 8) or vehicle (n = 7). NMA increased serum concentrations of both LH (by 80%; P < 0.05) and GH (by 700%; P < 0.01). We suggest that LH and GH secretion in gilts was enhanced by treatment with NMA.
Estienne
M J
MJ
Department of Agriculture, University of Maryland Eastern Shore, Princess Anne, MD, USA.
Harter-Dennis
J M
JM
Barb
C R
CR
Hartsock
T G
TG
D000818:Animals; D001522:Behavior, Animal / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D005260:Female; D013006:Growth Hormone / Q000097:blood*; D007986:Luteinizing Hormone / Q000097:blood*; D016202:N-Methylaspartate / Q000494:pharmacology*; D012741:Sexual Maturation / Q000502:physiology*; D013552:Swine / Q000378:metabolism* / Q000502:physiology; D013997:Time Factors
D016202:N-Methylaspartate; D007986:Luteinizing Hormone; D013006:Growth Hormone