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ARS Home » Research » Publications at this Location » Publication #76783
Title: SOMATOTROPHIC GENE EXPRESSION IN THE NEONATAL PIG

Author
item Matteri, Robert
item Carroll, Jeffery - Jeff Carroll

Submitted to: American Society of Animal Science
Publication Type: Abstract Only
Publication Acceptance Date: 3/19/1997
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: The mechanisms related to the pronounced early postnatal decline in growth hormone (GH) secretion are not well understood. The present study evaluated developmental changes in gene expression related to somatotrophic function in neonatal pigs. Male piglets were sacrificed at 1, 7, 14, 21, 28, 35, and 42 days of age (8/age group) for the collection of tissue and blood. Serum concentrations of GH were determined. Slot-blot evaluations of mRNA levels, normalized to beta-Actin, were performed for pituitary Pit- 1, GH, and GH-releasing hormone receptor (GHRHr). The expected age-related decline in circulating GH concentrations was observed (P < 0.001). Similarly, levels of pituitary GH and GHRHr mRNAs decreased with age (see Table). Pituitary Pit-1 mRNA levels at 7 and 14 days of age were significantly elevated relative to all other sampling times. Relative Units of specific mRNA at indicated postnatal ages. LSD = least significant difference interval. --------------------------- Age (Days) ---------------------------- mRNA 1 7 14 21 28 35 42 LSD P< GHRHr 2.89 1.98 1.38 1.37 0.71 0.75 0.71 1.12 .001 GH 1.25 1.12 1.22 0.60 0.40 0.48 0.33 0.78 .05 Pit-1 4.50 17.3 15.4 3.12 4.08 5.77 7.66 7.09 .001 Levels of GHRHr mRNA were significantly correlated with serum GH concentrations and levels of GH mRNA (r = .56, P < .05; both correlations). Pit-1 and GH mRNA levels also were correlated (r = .64, P < .01) These results reveal developmental regulation of pituitary gene expression related to somatotroph function during the neonatal period of the pig.