Acute Changes in Muscle Blood Flow and Concomitant Muscle Damage after an Intramuscular Administration

Abstract

Muscle contraction and hyperemia are not responsible for muscle damage at the injection site, which is the multifactorial phenomenon, involving intracellular calcium and inflammation.

Longitudinal Analysis of Gene Expression in Porcine Skeletal Muscle After Post-Injection Local Injury

“…This suggest that the pathophysiological reaction observed in this study at the molecular level is not anarchic but rather well organized. Several concomitant pathways had been already observed in a short term evaluation of the muscle blood flow response during the first 6 h following the IM administration, and the inhibition of each pathway induced a decrease in the observed blood flow, with or without reduction of the actual muscle injury (10). Similarly, in the current study about long-term muscle reaction, it is unclear which of the reaction pathways would be to inhibit or to enhance in order to ameliorate muscle healing.…”

“…Although histological studies are useful for documenting the muscle tolerance of the various formulations under development, they are descriptive only of the cellular events occurring in the muscle. The acute hemodynamic events occurring in the injected muscle have recently been evaluated in the rabbit (10), and different pathways leading to the acute muscle damage described. Further documentation of the development of drug-induced muscle lesions at the molecular level would improve the understanding of the muscle reactions, and could lead to the development of new well-tolerated formulations.…”