Author
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Mitchell, Alva |
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Wall, Robert |
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Submitted to: Journal of Federation of American Societies for Experimental Biology
Publication Type: Abstract Only Publication Acceptance Date: 1/20/2004 Publication Date: 1/20/2004 Citation: Mitchell, A.D., Wall, R.J. 2004. In vivo evaluation of changes in body composition of transgenic mice expressing the myostatin pro domain using dual energy x-ray absorptiometry [abstract]. FASEB Journal. 18(5):A210. Interpretive Summary: Technical Abstract: Previous results have shown that mice expressing a myostatin pro domain construct (MLC-Pro) have increased carcass weight and less epididymal fat compared to control mice. The purpose of this study was to use dual energy X-ray absorptiometry (DXA) to monitor, in vivo, the course of changes in body composition of control and MLC-Pro transgenic (TG) mice between 10 and 91 days of age. MLC-pro TG (n = 32) and littermate control (n = 28) mice were produced by mating G-3 male TG mice with non-TG females. At days 10, 20 and weekly thereafter to day 62, and finally at day 91, the mice were anesthetized and scanned by DXA. The DXA provided measurements of total body lean mass (LM), fat mass (FM), percentage of fat (%F), bone mineral content (BMC), and bone mineral density (BMD). By day 34, the body weight of the male TG mice was more than that of the control mice and was accompanied by a larger LM and a lower %F (P<0.05). By day 48, the male TG mice had higher measurements for both BMC and BMD (P<0.05). Finally at day 91, the male TG mice had 15.6% greater body weight, 19.4% more LM, 22.4% lower %F, 11.5% more BMC, and 4.4% higher BMD (P<0.05). The lower %F in the TG mice was due mainly to an increase in LM, rather than reduced FM. Measurements of the TG female mice were not different (P>0.05) from those of control female mice. Thus, this study demonstrates, using DXA, the onset and degree of differences in body composition of MLC-pro TG and littermate control mice. |
