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H. Jane Weems Chihal, S. C. Stone, and R. D. Peppler

Departments of Physiology, Anatomy, and Obstetrics and Gynecology, Louisiana State University Medical Center, New Orleans, Louisiana 70112, U.S.A.

Lipschütz (1927) suggested that the number of eggs shed by an animal is not determined by the number of ova present, but by some extra-ovarian factor. When Breward & Zuckerman (1949) attempted to test this hypothesis, they showed that multiple ovarian grafts in randomly bred female rats caused a decrease in follicular development and the weight of the ovaries in situ. These findings were later attributed to immunological rather than endocrinological factors (Mandl & Zuckerman, 1951). In the present study, the influence of `extra' ovarian tissue on the number of eggs ovulated and follicular development was re-investigated using highly inbred Fischer 344 rats. In such strains skin homografts are permanently accepted, verifying the isohistogenicity of the strain (Warren, Lofgreen & Steinmuller, 1973). Since skin grafts are more difficult to transplant permanently in

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R. D. Peppler, F. E. Hossler, and S. C. Stone

Summary. At 3-month intervals from birth to 27 months of age, 3 female armadillos were killed. The number and size of follicles >202 μm were determined, plasma progesterone concentration was measured, and values were correlated with age. Blood samples were taken monthly by femoral vein puncture and plasma was analysed by radioimmunoassay for progesterone concentration. At necropsy, both ovaries were visually inspected for a corpus luteum, weighed and then processed for routine histology. The number of normal, antral follicles >202 μm were counted. These follicles were arbitrarily categorized into 15 different size groups (every 77μm). Total number of follicles >202 μm varied from 15·5± 1·3 at 15 months of age to 26·3 ± 1·9 at 21 months. Follicles of a size (>978 μm) most likely to ovulate were present only at ≥9 months of age. Progesterone values remained below the adult concentration (5 ng/ml) until 15 months of age. A concentration of progesterone indicative of ovulation (∼ 10 ng/ml) occurred between 17 and 20 months of age. The findings of the present study demonstrate that the female armadillo is reproductively mature after 15 months of age.

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D. V. Brown, P. L. Senger, S. L. Stone, J. A. Froseth, and W. C. Becker

The roles of selenium (Se) and glutathione peroxidase in reproductive function are poorly understood, but it is possible that they may be important for normal reproduction in the male. In rats fed a Se-deficient diet, the testes accumulated and retained more 75Se than did other tissues 1 week after injection (Brown & Burk, 1972; Burk, Brown, Seely & Scaief, 1972). Autoradiographic studies (Brown & Burk, 1972) of spermatozoa recovered from rat epididymides have shown that 75Se is associated with the midpiece of the spermatozoon. Gould (1970) has suggested that 75Se is probably incorporated into late spermatocytes or early spermatids in the rat. Rotruck et al. (1973) demonstrated that Se is a component of glutathione peroxidase, an enzyme which has been reported to exist in dog, goat, ram and human semen (Li, 1975). The objectives of the present study were to determine whether glutathione peroxidase is present in ejaculated bovine semen and the relationship of the enzyme levels to sperm concentration and ejaculate volume.