Standardization of measurement of insulin-like growth factor I (IGF-I) by radioimmunoassay and monitoring of changes in concentration of hormone during the development of Nellore heifers under different food systems

• Grant number: 14/09135-9
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: November 01, 2014
• End date: January 31, 2016
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Reproduction
• Agreement: Coordination of Improvement of Higher Education Personnel (CAPES)
• Principal Investigator: Guilherme de Paula Nogueira
• Grantee: Marcos Antonio Maioli
• Host Institution: Faculdade de Medicina Veterinária (FMVA). Universidade Estadual Paulista (UNESP). Campus de Araçatuba. Araçatuba , SP, Brazil
• Associated scholarship(s): 15/08021-2 - Development and characterization of an FGF21 antibody in livestock and validation of radioimmunoassay methodology, BE.EP.DR

Abstract

This proposal will be divided into three experiments with the first, and principal, will have as its objective the establishment and validation of a method "in house" for measuring plasma IGF-I for the bovine specie by radioimmunoassay (RIA), currently unavailable on the market. For this, the process will be subjected to the following tests of validation: specificity and selectivity, linearity, range, precision and repeatability, accuracy (recovery), robustness, and sample stability. In experiments 2 and 3 will be measure IGF -I of experiments previously conducted by our laboratory team between the years 2010-2013 and 2009-2010 respectively, which aimed to evaluate the influence of different sources of energy supplementation (corn or fat) on age at puberty. Validation tests of the RIA for IGF-I as specificity, and accuracy/recovery will be assessed by Pearson correlation. Tests for stability and robustness are analyzed by analysis of variance with Tukey post-test. For comparison of hormone concentrations in the experiments with the different diets the ANOVA for repeated measures will be used, with dependent variable we considered the plasmatic concentrations of IGF-I and the independent variables will be considered time, group and interaction between group x time interval. The slice's test will be done to separate and compare the mean of the time intervals within each group and within time intervals. In addition to the comparisons between groups, will be performed the correlation between body weight and plasma IGF-I concentrations between experimental groups as well as the concentrations of gonadotropins and leptin. (AU)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

MAIOLI, Marcos Antonio. Measurement of insulin-like growth factor I (IGF-I) in bovine plasm by ELISA. 2016. Doctoral Thesis - Universidade Estadual Paulista (Unesp). Faculdade de Medicina Veterinária. Araçatuba Araçatuba.