LH, FSH, PRL AND ACTH CELLS IN PITUITARY-GLANDS OF COWS WITH OVARIAN CYSTS

We investigated morphometrically and densitometrically LH, FSH, PRL, a nd ACTH cells in pituitary glands in cows with follicular cysts and no rmal animals. Three groups were considered: cows in diestrus, cows in periestrus and cows with follicular cysts. The periestrous group was o btained by merging pro- and metaestrous groups, since the two did not differ when evaluated separately. The attribution to groups was confir med by plasma progesterone measurements and by postmortem examination of the ovaries. After immunocytochemical labeling the pituitary cells were counted, and their area and total immunoreactivity were measured. The results suggest hypofunction of the LH cells (P<0.05) and hyperfu nction of the ACTH cells (P<0.05) from the cows of the follicular cyst group. The FSH and PRL cells were similar in the three groups. These changes are consistent with the reduced LH release reported by most au thors in cows with follicular cysts and should be relevant to the path ogenesis of the bovine follicular cysts. The subnormal activity of LH cells might be secondary to the activation of the ACTH cells.