However, diameter and function of CL in females of the control group might have been greater than they were in the present study if the ovulatory follicle had been stimulated by the final 24 h of episodic LH secretion before the endogenous preovulatory LH surge.
Data from the present study indicate a dissociation of structural and functional development of the CL in cattle. Function of the CL of females from all groups treated with LHRH antagonist was reduced to the same extent as was the function of CL of females from the untreated control group, but the diameter of the CL was greater in females from the Ant 0 and Ant 2 groups than in those from the Ant —2 group. Episodic LH pulses after the preovulatory LH surge are therefore important for development of a CL of typical size.
The present data indicate that LH pulses after the preovulatory surge of LH are necessary for both structural and functional development of the CL in cattle. In sheep, LH has been reported to not stimulate mitogenic activity of mixed sheep luteal cell cultures. The function of LH in regulation of development of the luteal structure is therefore not clearly understood.