[Study of gene expression of melanin-concentrating hormone and of dynorphin in the rat hypothalamus by multiplex competitive RT-PCR].

Melanin-concentrating hormone (MCH) and dynorphin genes are expressed in two discrete neuron populations of the rat lateral hypothalamus. Their roles remain hypothetical in mammals. In order to analyze changes in MCH and dynorphin gene expression, we developed a multiplex competitive semi-quantitative RT-PCR allowing to study simultaneously the variations of their mRNAs. This technique was used to examine MCH and dynorphin mRNAs contents in rats food-deprived for 24 or 48 hours as compared to controls. A 2-fold induction of dynorphin mRNA by 24 hours, followed by a sharp decrease at 48 hours and return to control level were observed. A moderate increase in MCH mRNA content was noticed by 24 hours. A 48 hours fasting restored the control levels.