Determination of transforming growth factor-beta 2 (TGF-beta 2) in bovine colostrum samples.
Transforming growth factor-beta 2 (TGF-beta 2) is the major TGF-beta form in bovine colostrum. A colostrum pool of the five first milkings was made to validate an ELISA specific for human TGF-beta 2 for measure TGF-beta 2 concentration in bovine colostrum samples. According to this test > 90% of total TGF-beta 2 (74.5 +/- 4.4 ng/ml) in colostrum pool was in a latent form that could be activated by acetic acid treatment, whereas the concentration of the active form was only 4.19 +/- 0.27 ng/ml. Activated colostrum samples of the first milkings of five cows contained 150-1150 ng TGF-beta 2/ml and its concentration declined in correlation (r = 0.86) with total protein concentration to 12-71 ng/ml by the fifth milkings. Most of the TGF-beta 2 (94%) was found in the whey fraction of colostrum. The ELISA results were also compared with a TGF-beta 2 bioassay, the fibroblasts migration assay. This assay detected 9.8 +/- 1.0 ng/ml and 4.4 +/- 0.7 ng/ml in the activated and non-activated samples of colostrum pool respectively.
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Nutricia Fennica Ltd, Turku, Finland.
D000818:Animals; D002417:Cattle; D002465:Cell Movement; D003126:Colostrum / Q000737:chemistry*; D003429:Cross Reactions / Q000502:physiology; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005347:Fibroblasts / Q000166:cytology; D008722:Methods; D008892:Milk / Q000737:chemistry; D012680:Sensitivity and Specificity; D016212:Transforming Growth Factor beta / Q000032:analysis*
D016212:Transforming Growth Factor beta