Gender dimorphism in skeletal muscle leptin receptors, serum leptin and insulin sensitivity

• Published in: PloS one Vol. 3; no. 10; p. e3466
• Main Authors: Guerra, Borja, Fuentes, Teresa, Delgado-Guerra, Safira, Guadalupe-Grau, Amelia, Olmedillas, Hugo, Santana, Alfredo, Ponce-Gonzalez, Jesus Gustavo, Dorado, Cecilia, Calbet, José A L
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 21-10-2008; Public Library of Science (PLoS)
• Subjects: 17β-Estradiol; Adult; Body fat; Carrier Proteins; Cytokines; Diabetes; Diabetes and Endocrinology/Obesity; Dimorphism; Estrogens; Exercise; Fatty acids; Female; Gender differences; Human subjects; Humans; Insulin; Insulin - blood; Insulin resistance; Leptin; Leptin - blood; Leptin receptors; Male; Malnutrition; Men; Metabolism; Muscle, Skeletal - chemistry; Muscles; Musculoskeletal system; Perilipin-1; Phosphoproteins - analysis; Physical education; Physiology; Physiology/Endocrinology; Physiology/Integrative Physiology; Physiology/Muscle and Connective Tissue; Protein expression; Proteins; Receptors; Receptors, Leptin - analysis; Rodents; Sex Characteristics; Sex hormones; Skeletal muscle; SOCS-3 protein; Suppressor of Cytokine Signaling 3 Protein; Suppressor of Cytokine Signaling Proteins - analysis; Testosterone; Testosterone - blood; Tubulin; Tubulin - analysis; Tumor necrosis factor-TNF; Women; Women's Health; Women's Health/Cardiovascular Diseases in Women; Spain
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0003466

To determine if there is a gender dimorphism in the expression of leptin receptors (OB-R170, OB-R128 and OB-R98) and the protein suppressor of cytokine signaling 3 (SOCS3) in human skeletal muscle, the protein expression of OB-R, perilipin A, SOCS3 and alpha-tubulin was assessed by Western blot in muscle biopsies obtained from the m. vastus lateralis in thirty-four men (age = 27.1+/-6.8 yr) and thirty-three women (age = 26.7+/-6.7 yr). Basal serum insulin concentration and HOMA were similar in both genders. Serum leptin concentration was 3.4 times higher in women compared to men (P<0.05) and this difference remained significant after accounting for the differences in percentage of body fat or soluble leptin receptor. OB-R protein was 41% (OB-R170, P<0.05) and 163% (OB-R128, P<0.05) greater in women than men. There was no relationship between OB-R expression and the serum concentrations of leptin or 17beta-estradiol. In men, muscle OB-R128 protein was inversely related to serum free testosterone. In women, OB-R98 and OB-R128 were inversely related to total serum testosterone concentration, and OB-R128 to serum free testosterone concentration. SOCS3 protein expression was similar in men and women and was not related to OB-R. In women, there was an inverse relationship between the logarithm of free testosterone and SCOS3 protein content in skeletal muscle (r = -0.46, P<0.05). In summary, there is a gender dimorphism in skeletal muscle leptin receptors expression, which can be partly explained by the influence of testosterone. SOCS3 expression in skeletal muscle is not up-regulated in women, despite very high serum leptin concentrations compared to men. The circulating form of the leptin receptor can not be used as a surrogate measure of the amount of leptin receptors expressed in skeletal muscles.