Inhibition of growth and differentiation of fetal hamster gonads grafted into the adult testis.

A cytomorphological analysis of the effect of adult testes on growth and differentiation of grafted fetal testis or ovaries was performed in hamsters. Fetal gonads, taken at 14 days post-coital age, were grafted for 30 days either under the renal capsule or testicular capsule of scrotal or cryptorchid testes of adult hamsters (weight 115 +/- 23 g). Renal grafts were also performed in males castrated 30 days prior to receiving the fetal gonads.

Sex ratio of hamster fetuses assessed by gonadal morphology: effect of mother's age.

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.

Effect of castration and testosterone on norepinephrine storage and on the release of [(3)H]norepinephrine from rat vas deferens.

Norepinephrine and dopamine-?-hydroxylase, used as noradrenergic vesicle markers, were found to be decreased in the rat vas deferens 10 days after castration. Five days of testosterone administration to castrated animals increased the enzyme activity over that of controls but did not modify norepinephrine content. In tissue fractions obtained by differential centrifugation, the highest activities of the noradrenergic markers appeared in the vesicular fraction of controls and in the soluble fraction of castrated animals.

Effect of exogenous sex steroids upon the number of germ cells and the growth of foetal ovaries grafted under the kidney capsule of adult ovariectomized hamsters.

The effect of estradiol E, progesterone P and testosterone propionate T upon growth and germ cell population of foetal ovaries transplanted under the kidney capsule of adult ovariectomized hamsters was examined. Foetal ovaries were obtained 15 days postcoitum and the host received daily subcutaneous injections of E (1 micrograms/day), P (5 mg/day), T (500 micrograms/day) or E + P in 0.1 ml oil for 25 days beginning 5 days before grafting.

New observations on the onset and duration of the meiotic prophase in the female golden hamster (Mesocricetus auratus).

The onset and evolution of the meiotic prophase were assessed by histological and cytological techniques in fetal and neonatal ovaries obtained from day 13 postcoitum to day 11 postpartum in the golden hamster (Mesocricetus auratus). The histological technique based on the Feulgen stain and the cytological technique based on the Giemsa stain of isolated nuclei were judged to be specific for staining chromatin and chromosomal DNA. The results obtained with both techniques were quite similar and confirmed most of the meiotic prophase takes place during the neonatal period.

Embryo development under the effects of a new placental protein (UTPH) and its antiserum.

The effect of a human placental hormone (UTPH) and UTPH-antiserum upon development of preimplantation mouse embryos was studied in vitro. UTPH at a concentration of 90 micrograms/ml had a tendency to increase the mean number of blastomeres pre embryo, and increased significantly (P less than 0.01) upon the cleavage rate.

A method for the in vivo experimental study of meiotic prophase in the golden hamster (Mesocricetus auratus).

Gonads of 15 day-old hamster fetuses were grafted under the kidney capsule of adult ovariectomized females. In 81.8% of the grafts, the germ cells developed and completed meiotic prophase; they reached the diplotene stage and gave rise to primordial follicles.