4.11. cGMP Assay

Quantification of cGMP in LV samples were carried out by a direct competitive immunoassay (Abcam Plc., Cambridge, UK). After preparing standard curve, samples (n = 6 per group, each measured in duplicates) were homogenized in 0.1 M HCl. All steps were made as recommended by the manufacturer. The amount of competing cGMP-HRP conjugates bound to the plate was measured by reading optical density (OD) at 450 nm using a spectrophotometer (FLUOstar Optima, BMG Labtech, Ortenberg, Germany). The amount of cGMP was averaged, and expressed as pmol/mg tissue in each group. Student’s t-test was used to estimate differences between Control and HC animals.