Browsing by Author "CURY, M"

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    EFFECT OF EXOGENOUS SEX STEROIDS UPON THE NUMBER OF GERM-CELLS AND THE GROWTH OF FETAL OVARIES GRAFTED UNDER THE KIDNEY CAPSULE OF ADULT OVARIECTOMIZED HAMSTERS
    (1983) ARRAU, J; ROBLERO, L; CURY, M; GONZALEZ, R
    Effect of estradiol (E), progesterone (P) and testosterone propionate (T) upon growth and germ cell population of fetal ovaries transplanted under the kidney capsule of adult ovariectomized hamsters was examined. Fetal ovaries were obtained 15 days postcoitum and the host received daily s.c. injections of E (1 .mu.g/day), P (5 mg/day), T (500 .mu.g/day) or E + P in 0.1 ml oil for 25 days beginning 5 days before grafting. One day after the last injection, the size of the ovary, the germ cell population and plasma steroid levels were assessed. Results of hormone assays indicate that daily steroid administration was able to maintain continuously elevated plasma levels of the corresponding hormone. Interconversions or steroid secretion by the graft, if any, were not reflected in the peripheral circulation. Growth of the graft was stimulated by T and inhibited by P, in comparison with E and oil-treated controls. All germ cells were at the stage of primary-oocyte-forming part of a primordial or growing follicle. Their absolute number was significantly increased by T and E and significantly decreased by P and E + P. The number of oocytes per mm3 of ovary was increased 80, 48 and 40% with E, T and E + P, respectively. In the hamster, exogenous sex steroids given to the host can exert specific effects upon the growth and oocyte population of a grafted fetal ovary. Whether or not the action of steroids upon the graft is a direct one and whether they influenced oogonial mitosis, the evolution of the meiotic prophase or atresia of primary oocytes remains to be determined.
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    SEX-RATIO OF HAMSTER FETUSES ASSESSED BY GONADAL MORPHOLOGY - EFFECT OF MOTHERS AGE
    (1987) ARRAU, J; CURY, M; MADRID, F
    This paper describes the assessment of phenotypic sex in hamster fetuses 12-15 days postcoitum. External morphometric parameters such as body weight, crown-rump length and anus-genital distance did not permit the differentiation of males from females. The sex was determined easily by inspection of the internal genital structures under low power magnification on Days 13-15 postcoitum. The size, shape and location of the gonads and the presence of a conspicuous blood vessel on the testis were the most useful criteria. An inverse relationship was found between the age of the mother at conception and the number of fetuses in mothers 2 to 7 months old. The decrease in the number of fetuses with increasing age of the mothers affected preferentially the population of phenotypic males.