Effects of clenbuterol exposure on PPARγ expression in adipocytes of rats

ObjectiveTo investigate effects of clenbuterol (CLB) on the peroxisome proliferators-activated receptor γ (PPARγ) expression in adipose tissues of rats.MethodsTwenty adult female Sprague-Dawley rats were randomly divided into 4 groups (5 rats per group). CLB solved in normal saline solution was given at the dose of 0 mg/kg body weight (bw) (group A, as the control), 0.4 mg/kg bw (group B, low-dose group), 2.0 mg/kg bw (group C, mid-dose group), and 18.5 mg/kg bw (group D, high-dose group) for 14 d by gavage consecutively, respectively. Methods of immunohistochemistry, quantitative Real-time PCR and Western blotting were performed to detect expression of PPARγ in the adipose tissue samples.ResultsPPARγ-positive immunostaining was strong in the controls and weak in the experimental groups. There was no difference on PPARγ mRNA and protein between the low-dose group and the control (P>0.05). With the increase of CLB doses, expression levels of PPARγ mRNA and protein were significantly lower in mid- or high-dose group than those in the control (P<0.01).ConclusionsThe PPARγ expression in adipose tissues of rats could be down-regulated after CLB exposure, and the decrease became more severe with the increasing doses.