Luteinizing Hormone Is Important for the Maintenance of the Corpus Luteum

For most domestic animals, LH is the important Iuteotropin_i with the CL maintained in either nonpregnant or pregnant animals by a relatively slow pulsatile pattern of LH release (one pulse per 2-3 hours). In rodents, prolactin is the impor­tant Iuteotropin; daily biphasic release of prolactin is initiated by copulation, which is essential for the maintenance of the CL. Of the domestic species, prolactin has been implicated as a Iuteotropin in sheep and dogs.

Normal folliculogenesis, a prerequisite for ovulation, sets the stage for the subsequent development of the postovulatory CL. Thus, more clinical attention is paid to factors controlling the regression of the CL than to Iuteotropic factors.