Production of the proto-oncogene BAX does not vary with changing in luteal function in women

The mechanisms of luteal maintenance and regression in women are uncertain, but morphological and oligonucleosome studies raise the possibility that apoptosis may be involved. BAX is a proto-oncogene of the BCL-2 family which can induce apoptosis. The aim of this study was to determine whether BAX is expressed in the human corpus luteum and whether the level of expression changes relative to the stage of the luteal phase or in simulated early pregnancy. Carefully timed samples of corpus luteum were studied by immunostaining, sodium dodecyl sulphate-polyacrylamide gel electrophoresis and immunoblotting. BAX protein was immunolocalized in luteal sections from all stages including luteal rescue but BAX production did not change during luteal maintenance or regression. Localization of BAX to the steroid-secreting cells of the corpus luteum implies a functional role and BAX may interact with other members of the BCL-2 family to affect luteal function.