Fig. 1. Characteristics of animals used in this study and impairment of the hypothalamus-pituitary-ovary axis in streptozotocin-induced type I diabetes mellitus. (A) PCR and restriction enzyme digestion were carried out to confirm the presence of the ins2 gene mutation. Control and AKITA mice showed different PCR products after digestion. (B) The streptozotocin (STZ)-injected mice had a lower body weight and (C) higher blood glucose levels, compared to control mice (n=15). Different letters indicate a statistically significant difference (p<0.05). (D) Ovary size was dramatically reduced 3 weeks after STZ injection, while AKITA mice did not show any reduction in ovary size (n=6). (E) In STZ-injected mice, the expression of FSHR and luteinizing hormone/chorionic gonadotropin receptor (LHCGR) was substantially diminished compared with control and AKITA mice. (F) The expression of anti-Mullerian hormone (AMH), anti-estrogen receptor-beta (ER-beta), and Ki-67 in the ovaries from control, AKITA, and STZ-injected mice (50 µm, ×200). The expression levels of these proteins, which are correlated with folliculogenesis and proliferation, were reduced in STZ-injected mice. Different letters (a, b, c) indicate a statistical significant difference. H, heterozygous; W, wild type; CON, control; FSHR, follicle stimulating hormone receptor.