[Cyst formation in the ovaries of cows].

Used were 36 ovarian cysts to obtain an extract-antigen (ASTs) from their walls. Obtained were also an antiserum against ASTs cyst fluid, and bovine serum. Immunodiffusions and immunoelectrophoregrams of the ASTs antigens were carried out. Cyst and follicle fluids and blood sera from cystic and normal cows were likewise used in a diffusion with antisera against them. On the other hand, immunodiffusions and immunoelectrophoregrams were made with absorbed (exhausted) antisera and the antigens studied. The absorption was performed with heterologous antigens. The following results were obtained: 1. Variations exist as to the number, type, and distribution of the protein fractions. 2. When absorption has been carried out with heterologous antigens a specific protein fraction for ASTs and cyst fluid is established in the zone of the betaglobulins, which is lacking in the other antigens studied. The presence of this fraction points to the fact that the cyst fluid and the wall extract have a common origin. 3. The formation of the ovarian cysts is conditioned by the deficiency of iodine, the hypofunction of the thyroid gland, the disturbances of the nervous and hormonal correlation, etc., leading to functional and structural changes in the ovaries as well as to changes in the antigenic composition of the follicles and their walls.