PARENT SESSION

(W654) EFFECTS OF CHOLINERGIC SYSTEM BLOCKADE ON THE mRNA EXPRESSION OF GnRH IN BOTH SIDES OF THE PREOPTIC AND ANTERIOR HYPOTHALAMIC AREA OF CYCLIC FEMALE RATS.

Arteaga-Lopez, Paola¹, Dominguez, Roberto¹, Cerbon, Marco², Arrieta, Isabel ², Mendoza-Rodriguez, Carmen², Cruz, María ¹, ¹ FES Zaragoza UNAM, Biology of Reproduction Research Unit, Mexico City, DF, México² Facultad de Química UNAM, Mexico City, DF, Mexico

ABSTRACT- It has been shown that the right and left side of the preoptic anterior hypothalamic area (POA-AHA) regulate in asymmetrical way the gonadotropine secretion and ovulation. There is evidence that the expression of the mRNA for the gonadotropine releasing hormone (GnRH) has an asymmetric expression in the hypothalamus. There is also evidence that the cholinergic system of POA-AHA modulates the secretion of gonadotropins and ovulation in a circadian and asymmetric way. In present study we evaluate the effect of the blockade of the cholinergic system by the injection of atropine sulphate (ATR) on the GnRH mRNA expression. Total RNA of POA-AHA right and left sides was obtained of a group of six rats treated or not with ATR subcutaneously at 13:00 hs of the days of estrous (E) (300 mg/kg) or diestrous-1 (D1) (100 mg/kg). RT-PCR using specific primer for GnRH amplification was performed. GAPDH gene was used as a constitutive expression control. At the day of E, the injection of ATR resulted in a significant decrease in GnRH mRNA expression in both the right and left sides of POA-AHA (right side 0.80+/-0.1 vs. 5.56+/-0.4, p <0.05; left side 1.45+/-0.1 vs. 2.34+/-0.2, p <0.01). When the animals were treated on D1, only the right side showed a decrease in the GnRH mRNA expression (right side 1.35+/-0.1 vs. 6.20+/-0.4, p <0.05; left side 1.97+/-0.1 vs. 2.40+/-0.2). Present results suggest that cholinergic system stimulate the GnRH mRNA expression on the right side of POA-AHA. Supported by: CONACYT 121846, DGAPA IN 201005.

KEY WORDS: GnRH, asymmetry, estrous cycle, mRNA