Mature and immature oocytes in large and medium follicles after clomiphene citrate and human menopausal gonadotropin stimulation without human chorionic gonadotropin.

After ovarian stimulation with clomiphene citrate combined with human menopausal gonadotropin, 24 large (greater than 16 mm) and 16 medium (7 to 15 mm) human follicles were classified according to plasmatic estradiol (E2), luteinizing hormone (LH), and histology of the follicle and oocytes (in thin sections). An asynchronism of several hours between the stage of development of the largest and large cohort follicles is observed; overripeness of oocyte cumulus complex (OCC) is revealed. An asynchronous response to gonadotropins in granulosa and cumulus is also seen in the cohort of medium follicles of the same ovary, but not resumption of nuclear maturation of the oocyte. The efficiency of these oocytes after fertilization is discussed.

Timing of nuclear maturation and cumulus dissociation in human oocytes stimulated with clomiphene citrate, human menopausal gonadotropin, and human chorionic gonadotropin.

The maturation of the preovulatory human follicle larger than 16 mm is described between 0 and 36 hours after human chorionic gonadotropin (hCG) administration. The nuclear evolution of the oocyte is timed: prophase at 14 hours, germinal vesicle breakdown at 15 hours, metaphase I at 20 hours; metaphase II is complete by 35 hours. The quantified expansion of the cumulus is related to nuclear evolution. Almost complete expansion may already be observed 18 hours before ovulation (20 hours after hCG). The specific action of clomiphene citrate, human menopausal gonadotropin, and hCG stimulation on the granulosa induces a more rapid luteinization than is found after other means of stimulation or in spontaneous cycles. Oocytes from follicles less than or equal to 16 mm on preovulatory ovaries often show a reaction to hCG that may be related to their subsequent quality.

[Histologic aspects of some organs in the alloxan induced diabetic mouse]. / Aspects histologiques de quelques organes chez un modèle de diabète alloxannique de la souris.

In order to study the modifications in the activity on some CNS drugs by the experimental diabetes, the authors are proposing a model of alloxanic diabetes in the mouse. Diabetes is induced by administering pure alloxan to a well selected brand of mice. Biochemical and histological observations obtained on different vital organs are comparable with those obtained with spontaneously diabetic mice (stable and steady glycemia). This model is consequently a good way of assessing pharmacological comparison.