Effects of Combination of Thiazolidinediones with Melatonin in Dexamethasone-induced Insulin Resistance in Mice

A new mouse model of type 2 diabetes mellitus established through combination of high-fat diet, streptozotocin and glucocorticoid

AIM

A stable induced type 2 diabetes model (T2DM) still needs to be explored for basic and clinical research, due to nonuniform model methods and unstable consequences. Our aims were to explore and establish an optimized induced T2DM model in mice that exhibits insulin resistance and β-cell damage.

MATERIALS AND METHODS

C57BL/6 mice were treated with a high-fat diet (HFD), streptozotocin (STZ) and dexamethasone (DEX) at different doses and in combination. The general growth status, blood glucose and fasting insulin were detected, and the success rate and insulin sensitivity indices were calculated.

KEY FINDING

Low-dose STZ injection multiple times was more secure in the process of T2DM model production. Combined intervention was more efficient in reducing insulin sensitivity and improving the success rate of T2DM model construction.

SIGNIFICANCE

Combined with a high-fat diet, glucocorticoids and streptozotocin, a new mouse model of T2DM with insulin resistance and β-cell damage could be established. The optimized experimental method can serve as a stable model for further studies on the mechanisms and therapy of T2DM.

Melatonin for the treatment of spinal cord injury

Spinal cord injury (SCI) from trauma or disease severely impairs sensory and motor function. Neurorehabilitation after SCI is a complex medical process that focuses on improving neurologic function and repairing damaged connections in the central nervous system. An increasing number of preclinical studies suggest that melatonin may be useful for the treatment of SCI. Melatonin is an indolamine that is primarily secreted by the pineal gland and known to be regulated by photoperiodicity. However, it is also a versatile hormone with antioxidative, antiapoptotic, neuroprotective, and anti-inflammatory properties. Here, we review the neuroprotective properties of melatonin and the potential mechanisms by which it might be beneficial in the treatment of SCI. We also describe therapies that combine melatonin with exercise, oxytetracycline, and dexamethasone to attenuate the secondary injury after SCI and limit potential side effects. Finally, we discuss how injury at different spinal levels may differentially affect the secretion of melatonin.