Abstract
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 increase in collagen content by 47%, 44% and 61% in innervated gastrocnemius + drug, denervated control and denervated + drug in gastrocnemius muscles after 30 days of drug administration respectively. Collagen proliferation is β-agonist (Isoproterenol) specific confirmed with the simultaneously administration of β-antagonist propranolol (100 mg/kg body weight; 30 days). Van Gieson staining showed heavy collagen proliferation in epimysium region of muscle section and adventitia of blood vessels and some specialized regions. However, denervated gastrocnemius muscle represented a heavy collagen proliferation in the endomysium region also which is probably responsible for extensive collagen proliferation in denervated muscle after drug administration. SDS-PAGE of pepsin soluble collagen revealed five bands from origin to the point of migration γ, β1, β2, α1 and α2. SDS-PAGE of CNBr treated pepsin insoluble collagen pointed towards the more prominent remodeling of collagen metabolism in the β-agonist induced denervated gastrocnemius muscle after drug administration. From the present study, we can conclude that β-agonist, isoproterenol hydrochloride augments collagen proliferation in innervated as well as in denervated gastrocnemius muscle.
