PREMATURE MENOPAUSE AND OBESITY DUE TO OOCYTE LOSS IN FEMALE MICE CHRONICALLY EXPOSED TO LOW DOSE-RATE γ-RAYS

Long-term effects of continuous low dose-rate gamma-ray irradiation on mouse hematopoietic cells

The present work investigates the long-term effects of continuous low dose-rate (20 mGy/day to total doses of 1-8 Gy) gamma-ray exposure on the hematopoietic cells of specific pathogen-free C3H/HeN mice. Peripheral white blood cell (WBC) counts decreased on days 206, 471, and 486, with no significant changes in red blood cell (RBC) and platelet (PLT) counts. The number of colony forming units (CFU-S and CFU-GM) in the bone marrow and spleen from irradiated mice decreased with increasing total dose on day-12 and day-7. The decrease in bone marrow CFU-S persisted throughout the 400-day irradiation period and did not show any recovery up to 210 days postirradiation. These findings suggest that the effects of low-dose-rate (LDR) radiation on the hematopoietic system remain long after the 400-day irradiation was completed. Further investigation showed no significant difference in life spans of non-irradiated W/Wv (c-kit-deficient) mice inoculated with hematopoietic stem cells from irradiated (20 mGy/day for 400 days) or nonirradiated wild-type mice. These results suggest that the effects of continuous low-dose-rate irradiation are more pronounced in hematopoietic stromal cells than in HSCs themselves.

Role of anti-Mullerian hormone in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is the most common gynecological endocrine disorders affecting up to 10% of all females in their reproductive age, and its cause of onset is still elusive. A spectrum of recent research reflected diverse associations between increased plasma level of anti-Mullerian hormone (AMH) and different clinical features of PCOS. Since AMH levels reflect the pool of growing follicles that potentially can ovulate, it can be stated that serum AMH levels can be used to assess the “functional ovarian reserve,” rather mentioning it as the “ovarian reserve.” AMH also appears to be a premier endocrine parameter for the assessment of atrophied ovarian follicular pool in response to age of individuals. AMH hinders the follicular development as well as the follicular recruitment and ultimately resulting in follicular arrest which is the key pathophysiologic condition for the onset of PCOS. Furthermore, FSH-induced aromatase activity remains inhibited by AMH that aids emergence of other associated clinical signs of PCOS, such as excess androgen, followed by insulin resistance among the PCOS individuals. Given the versatile association of AMH with PCOS and scarcity in literature explaining the underling mechanisms how AMH relates with PCOS, this review article will discuss the roles of AMH in the pathogenesis of PCOS which may introduce a new era in treatment approach of PCOS.