Investigation of Serum Levels and Activity of Matrix Metalloproteinases 2 and 9 (MMP2, 9) in Opioid and Methamphetamine-Dependent Patients

Matrix metalloproteinases (MMPs) are a group of zinc-dependent proteolytic enzymes that play a role in extracellular matrix (mainly collagen) degradation and remodeling. MMPs are not only causes of the increase rewarding effects of drugs, but also act as pro-addictive agents. In this research, 22 morphine and 20 methamphetamine-dependent patients included and their serum levels and activity of MMP2 and 9 were assessed by ELISA and gelatin zymography and compared with those of 23 healthy individuals as a control group. Our findings showed a significant increase in serum levels and activity of MMP-2 in opium and methamphetamine groups in comparison with the control group. Moreover, unlike MMP-2, serum levels and activity of MMP-9 in both case groups found to be decreased. This study showed that long-term abuse of opium and methamphetamine changes the activity and serum levels of MMP9 and MMP2. The effects of methamphetamines and opium are associated with an increase in extracellular dopamine levels in the brain, achieved by facilitating the release of dopamine from pre-synaptic nerves. Our findings showed that serum levels and activities of MMP-9 and MMP-2 could be considered as alternative valuable biomarkers from those investigated of pro-addictive or anti-addictive factors in dependent patients.