Genetic analysis and cAMP measurement: comparison between lean and obese anovulating mice

Daniela Berguio Vidotti, Beatriz Schnabel, Mariane Secco, Priscila Cardoso Cristovam, Ricardo Carneiro Borra, Ismael Dale Cotrim Guerreiro da Silva

To evaluate genes differentially expressed in ovaries from lean (wild type) and obese (ob/ob) female mice and cyclic AMP production in both groups. The expression on messenger RNA levels of 84 genes concerning obesity was analyzed through the PCR array, and cyclic AMP was quantified by the enzyme immunoassay method. The most downregulated genes in the Obesity Group included adenylate cyclase-activating polypeptide type 1, somatostatin, apolipoprotein A4, pancreatic colipase, and interleukin-1 beta. The mean decrease in expression levels of these genes was around 96, 40, 9, 4.2 and 3.6-fold, respectively. On the other hand, the most upregulated genes in the Obesity Group were receptor (calcitonin) activity-modifying protein 3, peroxisome proliferator activated receptor alpha, calcitonin receptor, and corticotropin-releasing hormone receptor 1. The increase means in the expression levels of such genes were 2.3, 2.7, 4.8 and 6.3-fold, respectively. The ovarian cyclic AMP production was significantly higher in ob/ob female mice (2,229±52 fMol) compared to the Control Group (1,814±45 fMol). Obese and anovulatory female mice have reduced reproductive hormone levels and altered ovogenesis. Several genes have their expression levels altered when leptin is absent, especially adenylate cyclase-activating polypeptide type 1.