PMID- 8680413
OWN - NLM
STAT- MEDLINE
DCOM- 19960821
LR  - 20190920
IS  - 0953-8194 (Print)
IS  - 0953-8194 (Linking)
VI  - 5
IP  - 5
DP  - 1993 Oct
TI  - Effect of a single intravenous injection of N-methyl-D,L-aspartic acid on 
      secretion of luteinizing hormone and growth hormone in Holstein bull calves.
PG  - 469-73
AB  - The role of N-methyl-D-aspartate (NMDA) receptor activation in the central 
      regulation of luteinizing hormone (LH) and growth hormone (GH) was tested by 
      administering a bolus intravenous dose of N-methyl-D,L-aspartic acid (NMA), a 
      NMDA receptor agonist, to 24-week-old intact (n=5), estradiol-treated intact 
      (n=3) and castrated (n=3) Holstein bull calves. The calves were bled for 12h pre- 
      and 100 min post-NMA injection (1.75 mg-/kgBW) periods at 10 min intervals. 
      Concentrations of LH and GH in plasma were measured by specific RIA. Prior to 
      administration of NMA, the average concentration of LH, but not GH, differed 
      significantly among the 3 groups. As expected, administration of estradiol 
      prevented the normal ontogeny of pulsatile LH secretion, while castration 
      resulted in an increased frequency of LH discharges. Injection of NMA resulted in 
      an acute (P<0.001) release of LH in 3 of 5 intact and 3 of 3 estradiol-treated 
      intact calves with the peak response being observed at 20 min (3.18 +/- 1.3 and 
      5.58 +/- 1.3 ng/ml, respectively) following the challenge. Treatment with NMA did 
      not alter the release of LH in castrate calves. Concentrations of GH in plasma 
      increased (P<0.001) within 20 to 30 min after administration of NMA in intact, 
      estradiol-treated intact and castrate calves with a similar response being 
      observed in each group. Based on these findings, we suggest an involvement of 
      glutamatergic neurotransmission in the hypothalamic or supra-hypothalamic control 
      of LH and GH secretion, and that the excitatory effects of NMDA receptor 
      activation on LH release are overtly influenced by gonadal steroids in bull 
      calves.
FAU - Shahab, M
AU  - Shahab M
AD  - Department of Dairy and Animal Science, Pennsylvania State University, University 
      Park 16802-3503, USA.
FAU - Nusser, K D
AU  - Nusser KD
FAU - Griel, L C
AU  - Griel LC
FAU - Deaver, D R
AU  - Deaver DR
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, Non-P.H.S.
PL  - United States
TA  - J Neuroendocrinol
JT  - Journal of neuroendocrinology
JID - 8913461
RN  - 0 (Drug Implants)
RN  - 0 (Excitatory Amino Acid Agonists)
RN  - 4TI98Z838E (Estradiol)
RN  - 6384-92-5 (N-Methylaspartate)
RN  - 9002-67-9 (Luteinizing Hormone)
RN  - 9002-72-6 (Growth Hormone)
SB  - IM
MH  - Animals
MH  - Cattle/*physiology
MH  - Drug Implants
MH  - Estradiol/administration & dosage/pharmacology
MH  - Excitatory Amino Acid Agonists/administration & dosage/*pharmacology
MH  - Growth Hormone/*blood
MH  - Injections, Intravenous
MH  - Luteinizing Hormone/*blood
MH  - Male
MH  - N-Methylaspartate/administration & dosage/*pharmacology
MH  - Orchiectomy
MH  - Synaptic Transmission/drug effects/physiology
EDAT- 1993/10/01 00:00
MHDA- 1993/10/01 00:01
CRDT- 1993/10/01 00:00
PHST- 1993/10/01 00:00 [pubmed]
PHST- 1993/10/01 00:01 [medline]
PHST- 1993/10/01 00:00 [entrez]
AID - 10.1111/j.1365-2826.1993.tb00510.x [doi]
PST - ppublish
SO  - J Neuroendocrinol. 1993 Oct;5(5):469-73. doi: 10.1111/j.1365-2826.1993.tb00510.x.