Glimepiride

Glimepiride inhibits Kir6.2/SUR currents by interaction with two sites: a low-affinity site on Kir6.2 (IC(50)= approximately 400 mM) and a high-affinity site on SUR (IC(50)=3.0 nM for SUR1, 5.4 nM for SUR2A and 7.3 nM for SUR2B). ^[1] Glimepiride exhibits a higher potency compared to Glibenclamide with respect to stimulation of glucose transport, glucose transporter isoform 4 (GLUT4) translocation and lipid and glycogen synthesis in normal and insulin-resistant adipocytes and in muscle cells, as well as of the potential underlying signalling processes examined at the molecular level. Glimepiride associates in a time- and concentration dependent non-saturable manner with detergent-insoluble complexes of the plasma membrane which may correspond to caveolae. ^[2] Glimepiride blocks pinacidil-activated whole-cell K(ATP) currents of cardiac myocytes with an IC(50) of 6.8 nM, comparable to the potency of Glibenclamide in these cells. Glimepiride blocks K(ATP) channels formed by co-expression of Kir6.2/SUR2A subunits in HEK 293 cells in outside-out excised patches with a similar IC(50) of 6.2 nM. ^[3]

Glimepiride prevents the NA-STZ induced increased frequency of micronucleus (MN) in polychromatic and normochromatic erythrocytes. Glimepiride also decreases the sperm shape abnormality and enhances the sperm count besides improving the antioxidant status in the diabetic rats. Glimepiride inhibits the NA-STZ mediated changes in the MN frequency and sperm abnormality and enhanced the antioxidant defense. ^[4]