Remodeling of extracellular matrix protein, collagen by beta-adrenoceptor stimulation and denervation in mouse gastrocnemius muscle.
A chronic administration of isoproterenol hydrochloride (60 mg/kg body weight; 30 days) alters the collagen metabolism in denervated gastrocnemius muscle of mice. Hydroxyproline assay for collagen showed an increase in collagen content by 47%, 44%, and 61% in innervated gastrocnemius + drug, denervated control, and denervated + drug, respectively, in gastrocnemius muscles after 30 days of drug administration. Collagen proliferation is beta-agonist (isoproterenol) specific confirmed with the simultaneous administration of beta-antagonist propranolol (100 mg/kg body weight; 30 days). Van Gieson staining showed heavy collagen proliferation in the epimysium region of the muscle section and adventitia of blood vessels and some specialized regions. However, denervated gastrocnemius muscle represented a heavy collagen proliferation in the endomysium region, which also is probably responsible for extensive collagen proliferation in denervated muscle after drug administration. The SDS-PAGE of pepsin-soluble collagen revealed five bands from origin to the point of migration, gamma, beta1, beta2, alpha1, and alpha2. The SDS-PAGE of CNBr-treated pepsin-insoluble collagen pointed toward the more prominent remodeling of collagen metabolism in the beta-agonist-induced denervated gastrocnemius muscle after drug administration. From the present study, we can conclude that beta-agonist, isoproterenol hydrochloride, augments collagen proliferation in innervated as well as in denervated gastrocnemius muscle.
Kumar
Rakesh
R
Department of Biosciences, Himachal Pradesh University, Summer Hill, Shimla 171005 India.
Sharma
Sushma
S
D000318:Adrenergic beta-Agonists / Q000494:pharmacology*; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000818:Animals; D001835:Body Weight; D003094:Collagen / Q000187:drug effects* / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D007545:Isoproterenol / Q000494:pharmacology*; D008297:Male; D051379:Mice; D009121:Muscle Denervation; D018482:Muscle, Skeletal / Q000033:anatomy & histology / Q000294:innervation* / Q000378:metabolism*; D009929:Organ Size; D011433:Propranolol / Q000494:pharmacology; D011943:Receptors, Adrenergic, beta / Q000187:drug effects / Q000502:physiology
D000318:Adrenergic beta-Agonists; D000319:Adrenergic beta-Antagonists; D011943:Receptors, Adrenergic, beta; D003094:Collagen; D011433:Propranolol; D007545:Isoproterenol