Fig. 2

HFD-induced male spermatogenesis dysfunction was improved by irisin treatment. A Blood glucose level (n = 12). B Plasma insulin level (n = 12). C Plasma cholesterol level (n = 12). D-E Body weight and testes weight of the indicated groups (n = 12). F HE staining of mice testes. G Statistical analysis of the diameter of seminiferous tubules in the four groups (n = 6). H-J Sperm count, sperm viability and sperm motility (n = 6). K-M Serum FSH, LH and testosterone levels of the indicated groups (n = 6). N The mRNA expression of P450scc and P450c17 (n = 6). Data are presented as the mean ± SEM. ^*P < 0.05 vs. the matched control. Atrophied seminiferous tubules are marked with a double-head arrow. Impairment of the blood-testis barrier in the testis is marked with an arrowhead