Lactate receptor HCA1 (aka GPR81) is primarily expressed in adipose tissues and play roles in regulating fat metabolism. Hamsters have been often used as models for metabolic disorders such as dyslipidemia, obesity, and diabetes. In this report, we described the molecular characterization of hamster HCA1 and niacin receptor HCA2 using HCA1 ligands such as lactate, 3-hydroxybenzoic acid; 3,5-dihydroxybenzoic acid; 3-bromo-5-hydroxybenzoic acid; 3-chloro-5-hydroxybenzoic acid; 3-fluoro-5-hydroxybenzoic acid; and HCA2 ligands such as niacin, acifran, β-hydroxybutyrate; as well as HCA3 ligand 3-hydroxyoctanoic acid. Our results showed that 3,5-dihydroxybenzoic acid, 3-bromo-5-hydroxybenzoic acid; 3-chloro-5- hydroxybenzoic acid; 3-fluoro-5-hydroxybenzoic acid are specific ligands for hamster HCA1 and could be useful the hamster HCA1 in vivo activation.
Keywords: Diabetes, dyslipidemia, GPCR, HCA1, HCA2, lactate, niacin, obesity.