Olfactory Receptors, Golfαand Adenylyl Cyclase mRNA Expressions in the Rat Heart During Ontogenic Development

Golfα(a G heterotrimeric protein which shares a high homology with Gsα) expression was studied in the rat heart before birth and until weaning. Since Golfαin the neuro-olfactory epithelium is coupled to olfactory receptors and type III adenylyl cyclase, we looked for the presence of such molecules in the heart. GolfαmRNA was detected in the rat heart, highest levels being found in 21-day old fetuses until 3 days post partum. The protein amounts measured by Western blots paralleled the GolfαmRNA levels. Immunohistochemical studies revealed the presence of Golfαin atrial and ventricular cardiomyocytes. OL1 and latrophilin mRNAs, G protein-coupled olfactory receptors, were expressed at early postnatal stages. Adenylyl cyclase mRNAs for type II, type III, type V and type VI were expressed before birth and until weaning. Elements for an unexpected signaling pathway involving odorant receptors like OL1 and latrophilin, Golfαand type III adenylyl cyclase were expressed in rat heart, and appeared developmentally regulated.