Normal suppression of the reproductive axis following stress in corticotropin-releasing hormone-deficient mice

The hypothalamic neuropeptide CRH has been postulated to inhibit LH secretion by a central action within the brain. To characterize the physiological significance of CRH in stressor-induced inhibition of LH secretion, CRH-deficient and wild-type mice were subjected to restraint or food withdrawal, and plasma LH levels were determined. The proestrus LH surge of female mice was equally suppressed by restraint in both genotypes, and central administration of a CRH antagonist did not alleviate this suppression in either genotype. Male mice of both genotypes also demonstrated suppression of both LH and testosterone secretion following restraint. Furthermore, food withdrawal caused similar suppression of LH secretion in both female and male mice regardless of CRH status. These data demonstrate that CRH is not necessary to inhibit LH secretion following either restraint or food withdrawal and that other molecules are able to suppress LH secretion during the response to stress in the context of CRH deficiency.