Development of a technique for measuring insulin-like growth factor-I in swine:application to the study of the IN VIVO and IN VITRO effects of growth hormone in neonatal pigs
| dc.contributor.author | Scamurra, Ronald W. | en |
| dc.contributor.department | Biochemistry and Nutrition | en |
| dc.date.accessioned | 2019-07-03T18:56:39Z | en |
| dc.date.available | 2019-07-03T18:56:39Z | en |
| dc.date.issued | 1986 | en |
| dc.description.abstract | The relationship between porcine growth hormone (pGH) and insulin-like growth factor-I (IGF-I) in swine was investigated. IGF-I levels were measured by radioimmunoassay (RIA) with an antisera specific for human IGF-I after ultrafiltration of acidified samples. Ultrafiltration quantitatively separated carrier proteins and IGF-I. Failure to separate these species interfered with the RIA. Using this assay, swine chronically treated with pGH had 2.6-fold higher sera levels of IGF-I than controls, whereas, serum IGF-I from a hypophysectomized animal was only 4% that of normal animals. The ultrafiltration procedure was incorporated into a protocol to measure IGF-I in sera from neonatal swine treated with pGH (5O ug •kg BWt⁻¹•d⁻¹). Treatment of neonatal pigs with pGH for one or two weeks elevated pGH in sera, but did not significantly affect either growth or serum IGF-I concentrations. Preliminary studies were performed to determine if neonatal swine hepatocytes secreted IGF-I in vitro. Results indicated that neonatal hepatocytes synthesized limited quantities of IGF-I that approached the detection limits of the RIA. Furthermore, pGH did not stimulate hepatocyte IGF-I synthesis in vitro or in vivo. Neonatal hepatocytes synthesized a protein species that bound labeled IGF-I and had a molecular weight similar to a carrier protein in swine serum. Estimation of the rate of carrier protein synthesis suggested that IGF-I and carrier proteins are coordinately regulated in isolated neonatal hepatocytes. These results suggest that IGF-I is not inducible in the neonatal pig by GH therapy and that growth in neonatal swine is either maximal or GR-independent. | en |
| dc.description.degree | M.S. | en |
| dc.format.extent | ix, 102 leaves | en |
| dc.format.mimetype | application/pdf | en |
| dc.identifier.uri | http://hdl.handle.net/10919/91042 | en |
| dc.language.iso | en_US | en |
| dc.publisher | Virginia Polytechnic Institute and State University | en |
| dc.relation.isformatof | OCLC# 15285861 | en |
| dc.rights | In Copyright | en |
| dc.rights.uri | http://rightsstatements.org/vocab/InC/1.0/ | en |
| dc.subject.lcc | LD5655.V855 1986.S394 | en |
| dc.subject.lcsh | Growth regulators | en |
| dc.subject.lcsh | Swine -- Physiology | en |
| dc.title | Development of a technique for measuring insulin-like growth factor-I in swine:application to the study of the IN VIVO and IN VITRO effects of growth hormone in neonatal pigs | en |
| dc.type | Thesis | en |
| dc.type.dcmitype | Text | en |
| thesis.degree.discipline | Biochemistry and Nutrition | en |
| thesis.degree.grantor | Virginia Polytechnic Institute and State University | en |
| thesis.degree.level | masters | en |
| thesis.degree.name | M.S. | en |
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