Methodological aspects of blood flow measurement in ovaries containing corpora lutea

Ovarian blood flow measurements were carried out in pseudopregnant anesthetized rabbits in order to compare three different techniques. Direct measurement by venous cannulation and flow determination by 15-mum radioactive microspheres resulted in values 5 and 10 times higher, respectively, than indicator fraction technique using -86Rb. The direct method inevitably involves surgical handling of the ovary and its vessels, which may account for the lower values found with this method than with microspheres. A comparison between the dynamics of -86Rb uptake in the luteal ovary and the hindleg tissues, mainly consisting of striated muscle, indicated that this technique will underestimate ovarian blood flow due to a low ovarian extraction of the radionuclide. In the preparation for direct measurement the relation between blood pressure and flow was linear. This lack of autorgeulation is an important factor to consider in studies of ovarian steroid secretion rates. The radioactive microsphere technique appears to reflect physiological blood flow in the ovary and corpus leteum of the rabbit and can be useful in studies of vascular mechanisms in this gland.