Folic Acid Supplementation Modifies β-Adrenoceptor–Mediated In Vitro Lipolysis of Obese/Diabetic (+db/+db) Mice

The effects of folic acid (5.7 and 71 μg/kg, 4 weeks) consumption on the β-adrenoceptors (β-ARs)–elicited lipolysis in vitro of the abdominal adipocytes of lean/control (+ m/+ db) and obese/diabetic (+ db/+ db) mice (female) were investigated. β-AR agonists (salbutamol, a β2-AR agonist; BRL 37344 and CGP 12177, β3-AR agonists; adrenaline, a β-AR agonist)–mediated lipolysis, β2-, and β3-ARs protein expression of the adipose tissues after folic acid consumption were evaluated. Our results demonstrate that a smaller magnitude of the basal (spontaneous) and the β-AR agonists–triggered lipolysis was observed in + db/+ db mice, and folic acid supplementation (71 μg/kg) resulted in an improvement of both the baseline and the β-ARs–mediated lipolysis. In controls, a lower β2-and β3-ARs protein expression of the adipose tissues was detected in + db/+ db mice, compared to + m/+ db mice. In both strains fed with folic acid (71 μg/kg), a reduction of β2-AR protein expression was observed compared to the respective controls. In + db/+ db mice, folic acid (5.7 and 71 μg/kg) consumption caused a dose-dependent increase of β3-AR protein expression compared to controls. We demonstrate that lipolysis elicited by β-AR (β2- and β3-ARs) agonists was blunted in + db/+ db mice. Folic acid consumption has significant modulatory effects on β-ARs protein expression and lipolysis.