title: Compartmentalization of NO signaling cascade in skeletal muscles.
abstract: Skeletal muscle functions regulated by NO are now firmly established. However, the literature on the compartmentalization of NO signaling in myocytes is highly controversial. To address this issue, we examined localization of enzymes engaged in L-arginine-NO-cGMP signaling in the rat quadriceps muscle. Employing immunocytochemical labeling complemented with tyramide signal amplification and electron microscopy, we found NO synthase expressed not only in the sarcolemma, but also along contractile fibers, in the sarcoplasmic reticulum and mitochondria. The expression pattern of NO synthase in myocytes showed striking parallels with the enzymes engaged in L-arginine-NO-cGMP signaling (arginase, phosphodiesterase, and soluble guanylyl cyclase). Our findings are indicative of an autocrine fashion of NO signaling in skeletal muscles at both cellular and subcellular levels, and challenge the notion that the NO generation is restricted to the sarcolemma.
authors.affiliation: Gerhard Domagk Institute of Pathology, University of Muenster, Muenster, Germany. buchwalo@uni-muenster.de
authors.forename: Igor B
authors.initials: IB
authors.lastname: Buchwalow
authors.forename: Evgeny A
authors.initials: EA
authors.lastname: Minin
authors.forename: Vera E
authors.initials: VE
authors.lastname: Samoilova
authors.forename: Werner
authors.initials: W
authors.lastname: Boecker
authors.forename: Maren
authors.initials: M
authors.lastname: Wellner
authors.forename: Wilhelm
authors.initials: W
authors.lastname: Schmitz
authors.forename: Joachim
authors.initials: J
authors.lastname: Neumann
authors.forename: Karla
authors.initials: K
authors.lastname: Punkt
mesh_terms: D000818:Animals; D001483:Base Sequence; D002451:Cell Compartmentation; D017931:DNA Primers; D007150:Immunohistochemistry; D018482:Muscle, Skeletal / Q000201:enzymology / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000378:metabolism; D016133:Polymerase Chain Reaction; D051381:Rats; D015398:Signal Transduction
chemical_list: D017931:DNA Primers; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase