Effect of luteinizing hormone on the right regressing ovary of newly hatched chicks treated during embryonic development

We studied the histologic and stereological changes induced in the right ovary of newly hatched chicks treated with LH during their embryonic development. Results indicate that LH administration causes a diminution in size and total volume (P < 0.01) of the right ovary, as well as a decrease in the total volume of lacunar channels, blood vessels, and interstitium. Other changes obtained after LH treatment were a reduction (P < 0.001) in the number of germ cells, as well as an increase in the total volume of interstitial cell cords (P < 0.01). This expansion is due to the increase of cellular volume of interstitial cells (P < 0.001) and not to their number, which decrease in the LH-treated right ovary. All these modifications were similar to those occurring in the regressing right ovary during development. The findings suggest that the right ovary of the newly hatched chick is able to respond to LH treatment during embryonic development, inducing marked histologic changes that accelerate its regression.