A new technique for studying the uterine microvasculature in the rat

OBJECTIVE: Our purpose was to develop a method for direct measurement of rat uterine microvessels and to test their viability. STUDY DESIGN: In anesthetized female Sprague-Dawley diestrus rats, one uterine horn was isolated from the body cavity with its nerve and blood supply intact. A small fiberoptic probe inserted into the lumen of the uterus served as a light source for transillumination of uterine vessels. Diameters of circumferential arterioles were observed while increasing concentrations of vasoactive agonists were suffused over the uterus. RESULTS: No significant diameter changes occurred in circumferential arterioles of the control group (100-minute suffusion of Krebs solution). Dilation with papaverine (100 mu mol/L) demonstrated that vessels possessed basal tone. Circumferential arterioles showed concentration-dependent constriction to phenylephrine and angiotensin II and dilation to acetylcholine and serotonin. CONCLUSIONS: This uterine microcirculatory preparation provides a stable, reproducible model of a unique microcirculatory bed that responds to vasoactive agents in a manner similar to other microcirculatory beds.