Gender dymorphism in muscle leptin receptors

Abstract

To determine if there is gender dymorphism in the expression of leptin receptors (OB‐R170, OB‐R128 and OB‐R98) and perilipin in skeletal muscle we obtained muscle biopsies from thirty‐six healthy men (age = 27.2 ± 1.1 yr, height = 176.5 ± 0.97 cm, body mass = 77.1 ± 1.9 kg, body fat = 18.1 ± 0.5%; mean ± s.e.m.) and thirty‐two females (age = 26.7 ± 1.2 yr, height = 165.3 ± 1.1 cm, body mass = 61.3 ± 1.5 kg, body fat = 28.1 ± 1.2%; mean ± s.e.m.). The expression of OB‐R protein, perilipin and tubulin were analysed by Western blot in muscle biopsies obtained from the m. vastus lateralis, and in subcutaneous adipose tissue of the thigh (n=10). While the OB‐R128 and OB‐R98 where found in the skeletal muscle and adipose tissue, the OB‐R170 isoform was only detected in skeletal muscle. Leptin receptor expression was 43% (OB‐R170, P<0.05), 153% (OB‐R128, P<0.05) and 28% (OB‐R98; P=0.07) higher in females than in males, as well as perilipin content (+99%, P<0.001) and was related to the plasma leptin concentration (r=0.57, P<0.001). Plasma leptin concentration was 85% higher in females than in the males (P<0.05). Perilipin content in the adipose tissue was similar in males (n=5) and females 5(n=5).In summary, females express a greater amount of the long isoform of the leptin receptor in skeletal muscle. These results can not be explained by differences in fat tissue inside the skeletal muscle.