A method for longitudinal microscopic in vivo examinations of morphology, vascularity, and motility in the ovary and the oviduct of the rat.

OBJECTIVE

We developed an in vivo model to enable observation of dynamic changes in morphology, vascularity, and motility of the rat adnexa.

METHODS

Immature Sprague-Dawley rats (n = 16) were primed with equine chorionic gonadotrophin (eCG;15 IU) followed by human chorionic gonadotrophin (hCG; 15 IU) 48 hours later to induce ovulation. The experiments were performed during prolonged (up to 12 hours) thiobarbiturate anesthesia. During laparotomy the periovarian bursa was retracted, whereafter the oviductal-ovarian complex was submerged into an organ chamber. Water immersion lenses (4x-40x; final magnification up to 810x) enabled detailed observations that were recorded on Beta-SP videotape.

RESULTS

Capillary flow was monitored easily. At the level of the follicle, top blood flow velocity variations (8-10 per minute) were observed in the microvasculature. Ovulations were followed in detail, and oocyte-cumulus complexes were seen later in the oviductal ampulla. Regular contractions in the oviduct were synchronous with the oocyte-cumulus complexes moving back and forth in the oviductal lumen over a distance of about 900 microm. These contractions were more frequent (13-16 per minute) in the postovulatory phase compared with the time before ovulation (9-10 per minute). The oviductal contractions were initiated alternately from either end of the ampulla and were accompanied by a denudation of the oocytes, with a stream of cumulus cells seen moving in an abovarian direction in between contractions.

CONCLUSION

High-magnification video recording in vivo was useful for capturing microcirculatory events as well as structural and functional changes of the ovary and the oviduct.