Opioid Modulation of Follicle Stimulating Hormone (FSH) and Prolactin (PRL) Secretion in the Postpartum Sow
Lactation in the sow is characterized by an anestrous period that usually lasts up to 6 wk (Cole et al., 1975). Serum concentrations of luteinizing hormone (LH) are suppressed during lactation (Stevenson et al., 1981; Stevenson and Britt, 1980) while prolactin (PRL) concentrations are elevated (Bevers et al., 1978; Stevenson et al., 1981; Dusza and Krzymowska, 1981). Serum follicle stimulating hormone (FSH) concentrations increase gradually beyond the third week of lactation which appears to be related to a reduction in suckling frequency of the litter (Stevenson et al., 1981). Weaning generally results in an increase in serum LH and FSH (Cox and Britt, 1982; Shaw and Foxcroft, 1985) concentrations and a decrease in serum PRL concentrations (Bevers et al., 1978; van Landeghem and van de Wiel, 1978).
KeywordsLuteinizing Hormone Follicle Stimulate Hormone Luteinizing Hormone Secretion Endogenous Opioid Peptide Serum Follicle Stimulate Hormone
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