Evaluacion del eje hipotalamo-hipofiso-gonadal en hembras GABAB1 (-/-): ciclicidad y funcion reproductiva.

CATALANO, P. N; BONAVENTURA, M. M.; SILVEYRA, P.; BETTLER, B.; LIBERTUN, C.; LUX-LANTOS, V.

Buenos Aires

Congreso; SAIC 2005; 2005

SAIC

HYPOTHALAMIC-PITUITARY-GONADAL AXIS EVALUATION IN GABAB1KO FEMALE MICE: CYCLICITY AND REPRODUCTIVE FUNCTION. Catalano, P. N.1,2, Bonaventura, M. M.1, Silveyra, P.1, Bettler, B.3, Libertun, C.1,2 and Lux-Lantos, V.1 1 IBYME-CONICET, V. de Obligado 2490 (1428), Bs. As, Argentina. 2 Univ. de Buenos Aires, Argentina. 3 Univ. de Basilea, Suiza. e-mail: catalano@dna.uba.ar GABA, main inhibitory neurotransmitter, participates in endocrine regulation through receptors A, B or C. Recently, BALB/C mice lacking GABAB1 subunit expression (KO) was developed (Neuron 2001, 31:47-58), exhibiting profound neurological alterations. We have demonstrated basal hyperprolactinemia in males and advanced LH post-castration rise in females (Medicina 64, II, p 167, 2004). Here we evaluated cyclicity and reproductive function in female KO mice and wild type controls (WT) from the same colony. Estrous cyclicity: vaginal lavages were obtained daily from adult KO and WT mice for a fifty-day period (n: 18-22). Reproductive function: female adult mice of both genotypes were exposed to males of known fertility for a two-month period. Days to first delivery, the percentage of female mice pregnant after 30 days of male exposure and the number of pups/litter were recorded (n: 9-11). Female KO mice exhibited an extended estrus (p<0.001) and reduced proestrus period (p<0.001) as compared to WT controls. The number of mice becoming pregnant in the first 30 days of male exposure was significantly reduced in KO animals (% of pregnancies: WT: 87.5%, n=8 vs. KO: 37.5%, n=8, ÷2 test: p<0.05). The interval between exposing female KO mice to a male and delivery of the first litter was lengthened, though not attaining statistical significance (p<0.11). Only 1/8 WT vs. 3/8 KO females failed to get pregnant in the evaluated period. No difference in the number of pups/litter between genotypes was detected. Conclusions: Female KO mice exhibited altered cyclicity and compromised reproductive function. (UBA-CONICET-ANPCyT)