Estienne M J, Harter-Dennis J M, Barb C R, Hartsock T G
Department of Agriculture, University of Maryland Eastern Shore, Princess Anne, MD, USA.
Domest Anim Endocrinol. 1995 Apr;12(2):207-13. doi: 10.1016/0739-7240(94)00022-s.
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.
选用189日龄、体重96千克的青春期前约克夏小母猪，以确定静脉注射N-甲基-D，L-天冬氨酸（NMA）对促黄体生成素（LH）和生长激素（GH）循环浓度的影响。在实验1中，连续四天每天对4头小母猪每隔15分钟采集一次血样，共采集2小时。每天开始采样1小时后，按照4×4拉丁方处理安排，小母猪分别接受赋形剂（0.9%盐溶液）或1.25、2.5或5毫克NMA/千克体重的注射。处理对血清中LH浓度没有影响（P>0.1）。然而，与接受赋形剂处理的动物相比，接受2.5毫克NMA/千克体重注射的小母猪循环GH水平升高（1120%；P<0.05）。在实验2中，在注射NMA（10毫克/千克体重；n=8）或赋形剂（n=7）前1小时和后1小时，每隔15分钟从15头小母猪采集一次样本。NMA使血清LH浓度（升高80%；P<0.05）和GH浓度（升高700%；P<0.01）均增加。我们认为，用NMA处理可增强小母猪LH和GH的分泌。
