Presence of VIP, CGRP, SP neuropeptides and PAF-AH enzyme in porcine colostrum

Abstract

The aim of this study was to examine levels of vasoactive intestinal peptide (VIP), calcitonin gene-related peptide (CGRP), substance P (SP) and platelet activating factor-acetylhydrolase (PAF-AH) in porcine serum and colostrum. Samples of porcine blood were obtained from six multiparous sows during farrowing and post-lactation. Porcine colostrum was obtained from lactating sows at parturition. Neuropeptides were measured by competitive enzyme immunoassay using streptavidin-conjugated horseradish peroxidase (VIP) and acetyl cholinesterase-peptide conjugates (SP and CGRP) as tracers. PAF-AH activity was measured by a continuous kinetic assay using 2-thio PAF as substrate. The presence of VIP, CGRP, SP and PAF-AH activity in both porcine serum and colostrum was confirmed. The concentrations of VIP, CGRP and PAF-AH in serum and colostrum were comparable, suggesting passive rather than active secretion in the colostral milk. A significant higher concentration of SP was found in porcine colostrum. This could be explained by active secretion into colostrum or production of SP in the mammary gland. The presence of these factors in porcine colostrum may be important for the maturation of the gastrointestinal system in neonatal piglets. However, further research is necessary in order to elucidate the role of these factors in porcine colostrum.