PMID- 7789312 OWN - NLM STAT- MEDLINE DCOM- 19950721 LR - 20181130 IS - 0013-7227 (Print) IS - 0013-7227 (Linking) VI - 136 IP - 7 DP - 1995 Jul TI - N-methyl-D-aspartic acid receptor messenger ribonucleic acid levels and luteinizing hormone release in immature female rats: effects of stage of pubertal development and exposure to ethanol. PG - 2874-80 AB - This research was designed to determine 1) whether changes occur in the levels of N-methyl-D-aspartic acid (NMDA) receptor (NMDA-R) messenger RNA (mRNA) in the reproductive hypothalamus of female rats as they approach puberty, 2) whether NMDA-R stimulation would promote differential LH responses during the specific stages of peripubertal development, and 3) whether ethanol (ETOH), which is known to affect the NMDA-R in other brain systems, can alter NMDA-R-activated LH secretion at puberty. In the first experiment, female rats were killed at 15, 20, 25, and 34-36 days of age to determine the levels of mRNA that code for the NMDA-R, specifically NMDA-R1, in the arcuate nucleus-median eminence (AN-ME) and preoptic area (POA) during pre- and peripubertal development by a ribonuclease protection assay. Results indicate that in juvenile animals, NMDA-R mRNA levels in the AN-ME increased at 25 days (P < 0.01). In the POA, the levels increased at 20 days (P < 0.05), but were unchanged at 25 days. During the peripubertal period, NMDA-R gene expression in the AN-ME did not change; however, gene expression in the POA increased (P < 0.05) during first proestrus, then declined during first estrus. In the second experiment, NMDA-R stimulation with N-methyl-D,L-aspartic acid (NMA; 2.5 mg/kg) produced differential stimulatory effects on LH release depending upon the stage of pubertal development. In this regard, significant post-NMA percent increases in LH released over pre-NMA (basal) levels occurred during anestrus (46%; P < 0.01) and first proestrus (95%; P < 0.01), with nonsignificant increases of 18% and 28% during first estrus and diestrus, respectively. Finally, a 3 g/kg dose of ETOH given intragastrically 90 min before the NMA challenge blocked (P < 0.05) NMA-induced LH release during first proestrus. In conclusion, these findings demonstrate regional differences in the timing of NMDA-R gene expression in the reproductive hypothalamus during pubertal development, show differential responses of LH to NMDA-R activation during the peripubertal period, and continue to demonstrate the vulnerability of the hypothalamic-pituitary axis to the detrimental effects of ETOH at this critical time of development. FAU - Nyberg, C L AU - Nyberg CL AD - Department of Veterinary Anatomy and Public Health, Texas A&M University, College Station 77843, USA. FAU - Srivastava, V AU - Srivastava V FAU - Hiney, J K AU - Hiney JK FAU - Lara, F AU - Lara F FAU - Dees, W L AU - Dees WL LA - eng GR - K02-AA-00104/AA/NIAAA NIH HHS/United States GR - R01-AA-07216/AA/NIAAA NIH HHS/United States PT - Journal Article PT - Research Support, U.S. Gov't, P.H.S. PL - United States TA - Endocrinology JT - Endocrinology JID - 0375040 RN - 0 (RNA, Messenger) RN - 0 (Receptors, N-Methyl-D-Aspartate) RN - 3K9958V90M (Ethanol) RN - 6384-92-5 (N-Methylaspartate) RN - 9002-67-9 (Luteinizing Hormone) SB - IM MH - Animals MH - Arcuate Nucleus of Hypothalamus/metabolism MH - Ethanol/*pharmacology MH - Female MH - Luteinizing Hormone/*metabolism MH - Median Eminence/metabolism MH - N-Methylaspartate/pharmacology MH - Preoptic Area/metabolism MH - RNA, Messenger/*metabolism MH - Rats MH - Rats, Sprague-Dawley MH - Receptors, N-Methyl-D-Aspartate/*genetics MH - Sexual Maturation/*physiology EDAT- 1995/07/01 00:00 MHDA- 1995/07/01 00:01 CRDT- 1995/07/01 00:00 PHST- 1995/07/01 00:00 [pubmed] PHST- 1995/07/01 00:01 [medline] PHST- 1995/07/01 00:00 [entrez] AID - 10.1210/endo.136.7.7789312 [doi] PST - ppublish SO - Endocrinology. 1995 Jul;136(7):2874-80. doi: 10.1210/endo.136.7.7789312.