The effect of calorie restriction on the presence of apoptotic ovarian cells in normal wild type mice and low-plasma-IGF-1 Laron dwarf mice

摘要

Background It is known that caloric restriction extends lifespan and can minimize age-related dysfunction of the reproductive system. We became interested in how caloric restriction influences apoptosis, which is a crucial process that maintains ovarian cell homeostasis. Methods We examined ovarian cells in: 2.5-year-old wild type mice on caloric restriction (CR) or fed ad libitum (AL) and Laron dwarf mice (GHR-KO) at the same ages on CR or fed AL. Apoptosis was assessed by histochemical analysis on paraffin sections of ovarian tissue. Results Morphological and histochemical analysis revealed that CR improved reproductive potential in 2.5-year-old WT littermates and GHR-KO female mice, as indicated by the increased number of ovarian follicles. The level of apoptosis in ovarian tissue was higher in WT mice on a CR diet compared with WT mice on the AL diet. In GHR-KO mice, the level of apoptosis in ovaries was similar for mice on CR and on AL diets and bigger than in WT mice on CR. Conclusions Morphological and histochemical analysis revealed a younger biological age of the ovaries in 2-year-old WT littermates and GHR-KO female mice on CR compared with animals fed AL.