The Effect of MitoTEMPO on Rat Diaphragm Muscle Contraction Parameters in an Experimental Diabetes Model Induced with Streptozotocin

Abstract

Objective: Diabetes Mellitus (DM) not only causes hyperglycemia but also leads to clinical challenges involving respiratory functional impairments. The contraction of the diaphragm reduces pleural pressure, thereby contributing significantly to the process of breathing. This study examines the functional impairments in diaphragm muscle isometric contraction parameters due to increased reactive oxygen species (ROS) associated with DM, as well as the effects of MitoTEMPO, a mitochondria-specific antioxidant, on these impairments.

Methods: Wistar Albino male rats at 12-14 weeks of age were randomly divided into three groups: the control group (CON, n=6), the diabetes group (DM, n=6), and the diabetes + MitoTEMPO (MT, n=6) group. A single dose of 50 mg/kg streptozotocin (STZ) was administered to the rats in the DM and MT groups. When the rats in the MT group reached a blood glucose level of 300 mg/dl, they were administered MitoTEMPO at a dose of 0.7 mg/kg/day for 28 days. Isometric contraction recordings were obtained from diaphragm muscle preparations isolated from the experimental animals at the end of the 28-day period.

Results: Although the effectiveness of mitochondria-specific antioxidants in reducing blood glucose levels in DM is debated in the literature, results for the MT group were interestingly indicative of a statistically significant decrease in blood glucose levels following MitoTEMPO administration at the end of the fourth week. Furthermore, MitoTEMPO exhibited therapeutic effects on diaphragm muscle contraction parameters impaired by DM.

Conclusion: The findings suggest that in DM patients, MitoTEMPO could be utilized for blood glucose control and might also be effective in the treatment of DM-induced diaphragm muscle mechanical dysfunction.