Effects of vitamin D3 on in vivo labelling of chick skeletal muscle proteins with [3H]leucine.

The effects of the administration of a single oral dose of vitamin D3 to rachitic chicks on the in vivo incorporation of [3H]leucine to proteins of skeletal muscle subcellular fractions was studied. A significant stimulation (50%) of labelling of mitochondrial proteins could be seen. The sterol affected the labelling of sarcoplasmic reticulum (20%) and contractile proteins (10%) to a lesser extent. These results confirm previous observations which implicate vitamin D3 in the synthesis of mitochondrial proteins.