The Proliferative Response of Mouse Jejunal Crypt Cells to Radiation-Induced Cell Depletion is not Mediated Exclusively by Transforming Growth Factor Alpha

Evans, S. C., Mack, D. C., Mason, K. A. and Thames, H. D. The Proliferative Response of Mouse Jejunal Crypt Cells to Radiation-Induced Cell Depletion is not Mediated Exclusively by Transforming Growth Factor Alpha. Radiat. Res. 155, 864–867 (2001). Several lines of correlative evidence link transforming growth factor alpha (Tgfa, also known as TGF-α) to proliferative activity in jejunal crypt cells. It is therefore tempting to hypothesize that, as a ligand of the epidermal growth factor, it mediates the compensatory proliferative burst in the crypts after radiation-induced cell killing. We have tested this hypothesis by comparing the repopulation response of wild-type and Tgfa-null mice, using the microcolony assay. Mice were exposed whole-body to 137Cs γ rays at a dose of approximately 1.6 Gy/min. Single doses and equal doses separated by 4 and 54 h were given. The rightward shift of the dose–response curves for 54 h was identical for wild-type and Tgfa-null mice, and there was no indication of ...