Apoprotein B localization in control and streptozotocin-diabetic rat skeletal muscles

This communication documents for the first time the presence of an endogeneous macromolecule of biological importance, a lipoprotein, inside normal rat skeletal muscle cells but absent in those from rats made diabetic by streptozotocin treatment. Apoprotein B was localized in the vascular components and interstitial spaces surrounding both control and diabetic extensor digitorum muscles as revealed by immunofluorescence. However, in muscles from control but not diabetic rats, apoprotein B was also observed inside the myofibres, especially in regions adjacent to capillaries. The staining pattern was unaltered by the addition of albumin to the antisera and was absent in all situations in which absorbed antisera were tested.