The effect of mating upon LH release in male and female voles of the species Microtus agrestis.

Members of the microtine species are probably reflex ovulators. The prairie vole, Microtus ochrogaster (Richmond & Conway, 1969), the meadow vole, M. pennsylvanicus (Clulow & Mallory, 1970), the levant vole, M. guentheri (Bodenheimer & Sulman, 1946), the Californian vole, M. californicus (Greenwald, 1956), and the montane vole, Microtus montanus (Gray, Davis, Zerylnick & Dewsbury, 1974) have all been regarded as coming into this category and Breed (1967) has demonstrated that members of M. agrestis are also reflex ovulators. As ovulation is normally preceded by a surge of LH in the blood, post-coital levels of serum LH were measured by radioimmunoassay in female and male voles (M. agrestis) after mating. The method used was that described by Niswender, Midgley, Monroe & Reichert (1968) for rat LH, as modified by Naftolin & Corker (1971). The voles in these experiments were sexually mature adults from the Departmental colony. The females weighed approximately 20 g, and the males about 25 g. Matings took place in circular glass troughs 20 cm in diameter, and 10