Figure 1
Serial sections of rat gastrocnemius muscle. This is muscle after a 1 hr treadmill run processed through in situ hybridization, histochemistry, and immunohistochemistry. (A) Intracellular location (dark stain) of VEGF165 mRNA transcripts from in situ hybridization with representative type I, IIa, IIb and IId/x fibers indicated. (B) Sense strand control from in situ hybridization which shows no significant non-specific background staining in this protocol. (C) Myofibrillar actomyosin ATPase staining procedure to identify type I (dark stain), type IIa (light stain), and the mixed population of type IIb-IId/x (medium stain) fibers. (D) Positive binding of 2B MHC antibodies (BF-F3) to type IIb fibers is shown as dark stain. (E) Positive binding of slow MHC antibodies (NCL-MHCs) to type I fiber shown as dark stain. (F) Positive binding of 2A MHC antibodies (A4-74) to type IIa fibers shown as dark stain. Magnification by 25× objective in all photos.