Ovulation induction: Follicular selection in the cyclic hamster: a 1960 model

Abstract

In the early 1960s, I completed a series of studies analysing the factors regulating follicular selection in the cyclic hamster. The hamster was the ideal model for several reasons: (i) the extreme regularity of the 4-day oestrous cycle (day 1 = oestrus; day 4 = pro-oestrus); (ii) the ability to monitor the day of the cycle by the conspicuous gross vaginal discharge on day 1; (iii) the fact that the cycle is maintained in the face of excessively elevated concentrations of oestrogens, induced by superovulation, which would disrupt the oestrous cycle of the rat. The experimental manipulations were all carried out within the course of one cycle and the principal end-points were recovery and counting of oviductal ova on the morning of day 1 and ovarian histology.When one ovary was removed (unilateral ovariectomy) on the morning of day 1, 2 or 3, the remaining ovary compensated by the next day 1 by ovulating 10 eggs whereas deferring 2225

In Vivo Imaging of Physiological Angiogenesis from Immature to Preovulatory Ovarian Follicles

“…23 Moreover, the hamster is suitable for the use of the skinfold chamber preparation that allows intravital microscopic observations of follicular transplants in conscious animals throughout a prolonged period of time. The availability of different fluorescent markers for ex vivo and in vivo staining extended the possibilities of intravital microscopy from purely morphological analysis to the study of complex physiological and cellular events.…”

Inhibition of p53 during physiological angiogenesis in the hamster ovary does not affect extent of new vessel formation but delays vessel maturation

“…Because the 4-day oestrous cycle of the hamster is extremely regular and is maintained even in the face of excessively elevated concentrations of estrogens (Greenwald 1995), as used to induce superovulation in the present study, the hamster is thought to be an ideal model for the analysis of follicular angiogenesis. Moreover, the hamster is highly suitable for the skinfold chamber preparation (Endrich et al 1980;Menger et al 2002) allowing intravital microscopic observations of follicular transplants over a prolonged period of time.…”