Sexually dimorphic effects of NMDA receptor antagonism on brain–pituitary–gonad axis development in the platyfish

• Published in: Comparative biochemistry and physiology. Toxicology & pharmacology 2002, Vol.131 (1), p.9-18
• Main Authors: Flynn, Katherine M, Miller, Shelly A, Sower, Stacia A, Schreibman, Martin P
• Format: Article
• Language: English
• Subjects: Animals; Cyprinodontiformes; Dizocilpine Maleate - pharmacology; Excitatory Amino Acid Antagonists - pharmacology; Female; Fishes; Freshwater; Glutamate; Gonadotropin releasing hormone; Gonads - drug effects; Immunocytochemistry; Immunohistochemistry; Life Sciences (General); Male; MK-801; NMDA; Pisces; Pituitary Gland - anatomy & histology; Pituitary Gland - drug effects; Puberty; Receptors, N-Methyl-D-Aspartate - antagonists & inhibitors; Receptors, N-Methyl-D-Aspartate - physiology; Reproduction; Sex Characteristics; Sexual dimorphism; Sexual Maturation - drug effects; Sexual Maturation - physiology; Space life sciences; Tissue Distribution; Weight Gain - physiology
• ISSN: 1532-0456; 1878-1659
• DOI: 10.1016/S1532-0456(01)00258-7

The N-methyl- d-aspartate glutamate receptor (NMDAR) is found in hypothalamic nuclei involved in the regulation of reproduction in several species of mammals and fishes. NMDAR is believed to affect reproductive development and function by regulating gonadotropin releasing hormone (GnRH)-producing cells. These pathways are likely to be sexually dimorphic, as are several other neurotransmitter systems involved in reproductive function. In this report, male and female platyfish received intraperitoneal injections of 0, 5, 10, 20, 40 or 60 μg/g body wt. of the non-competitive NMDAR antagonist MK-801. Injections began at 6 weeks of age and continued thrice weekly until control animals reached puberty, as evidenced by anal fin maturation. The percent of pubescent animals was significantly affected by sex and treatment, with fewer MK-801-injected females in puberty than control females at each dose ( P