Summary
The pattern of follicular development during the estrous cycles of aged rats was examined and compared with that of mature rats. In both, preovulatory follicles are derived from a select group of small pre-Graafian follicles which begin to develop at estrus and reach the preovulatory size by the morning of proestrus, but the rate of growth, as judged by an increase in the percentage of granulosa cells incorporating 3H-thymidine, is accelerated in the follicles of aged rats. A second mechanism, which accounts for preovulatory follicles in aged rats, involves the rescue from atresia of pre-Graafian and preovulatory follicles. The existence of this mechanism is supported by the observation that at metestrus in aged rats virtually all follicles, regardless of their state of atresia, possess a high percentage of granulosa cells incorporating 3H-thymidine, indicating that the follicles are growing rapidly. However, some of these rapidly growing follicles show signs of atresia such as pyknotic nuclei within their granulosa cell layers. Since follicles in the initial stage of atresia contain defective oocytes (Peluso et al. 1979b), their rescue and development into preovulatory follicles would result in the ovulation of defective oocytes, a fact which accounts in part of the lower fertility in these older animals.
References
Byskov AG (1979) Atresia. In: Midgley AR, Sadler WA (eds) Ovarian follicular development and function. Raven Press, New York, pp 41–58
Fugo NW, Butcher RL (1971) Overripeness and the mammalian ova I. Overripeness and early embryonic development. Fert Steril 17:804–814
Goldenberg RL, Vaitukaitis JL, Ross GT (1972) Estrogen and follicle stimulating hormone interactions on follicle growth in the rat. Endocrinology 90:1492–1498
Greenwald GS (1974) Role of follicle-stimulating hormone and luteinizing hormone in follicular development and ovulation. In: Handbook of Physiology, Vol II, section 7, chapter 33. American Physiological Society, pp 293–323
Harman SM, Talbert GB (1970) The effect of maternal age on ovulation, corpora lutea of pregnancy, and implantation failure in mice. J Reprod Fert 23:33–39
Harman SM, Talbert GB (1974) Effect of maternal age on synchronization of ovulation and mating and on tubal transport of ova in mice. J Geront 29:493–498
Hirshfield AN, Midgley AR (1978a) Morphometric analysis of follicular development in the rat. Biol Reprod 19:597–605
Hirshfield AN, Midgley AR (1978b) The role of FSH in the selection of large ovarian follicles in the rat. Biol Reprod 19:606–611
Hoak DC, Schwartz NB (1980) Blockage of recruitment of ovarian follicles by suppression of the secondary surge of follicle-stimulating hormone with porcine follicular fluid. Proc Natl Acad Sci U.S.A. 77:4953–4956
Parkening TA, Soderwall AL (1973a) Delayed embryonic development and implantation in senescent golden hamsters. Biol Reprod 8:427–434
Parkening TA, Soderwall AL (1973b) Preimplantation stages from young and senescent golden hamsters: Presence of succinic dehydrogenase and non-viable ova. J Reprod Fert 35:373–376
Peluso JJ, Hutz R (1980) The effect of age on the ability of oocytes to synthesize RNA and proteins during in vitro maturation. Cell Tissue Res 213:29–35
Peluso JJ, Steger RW (1978) Role of FSH in regulating granulosa cell division and follicular atresia in rats. J Reprod Fert 54:275–278
Peluso JJ, Steger RW, Huang H, Meites J (1979a) Pattern of follicular growth and steroidogenesis in the ovary of aging cycling rats. Exp Aging Res 5:319–333
Peluso JJ, Bolender DL, Perri A (1979b) Temporal changes associated with the degeneration of the rat oocyte. Biol Reprod 20:423–430
Peluso JJ, England-Charlesworth C, Hutz R (1980a) Effect of age and follicular aging on the preovulatory oocyte. Biol Reprod 22:999–1005
Peluso JJ, Montgomery MK, Steger RW, Meites J, Sacher G (1980b) Aging and ovarian function in the white-footed mouse (Peromyscus leucopus) with specific reference to the development of preovulatory follicles. Exp Aging Res 6:317–327
Peluso JJ, Hutz R, England-Charlesworth C (1982) Development of preovulatory follicles and oocytes during the estrous cycle of mature and aged rats. Acta Endocrinol (in press)
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Peluso, J.J., Downey, C. Pattern of follicular development during the estrous cycle of aged rats. Cell Tissue Res. 225, 229–234 (1982). https://doi.org/10.1007/BF00216232
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DOI: https://doi.org/10.1007/BF00216232