PMC

Washed human platelets (325 × 10⁶ cells per condition) were treated with vehicle or with BAY 41-2272 (16 µM, A), YC-1 (100 µM, B), and PPIX (100 µM, C) for 1 min or pretreated for 15 min with TSP-1 followed by 1 min for the respective drug or TSP-1 alone. Platelet aggregation was induced with thrombin (1 U) and assessed under high shear conditions. (D) Represents the replicate platelet aggregation data expressed as mean ± SD (n= 3). *P < 0.05 versus control, **P < 0.05 versus non-TSP-1 pretreated. TSP-1, thrombospondin-1.

Porcine VSMCs (A) or washed human platelets (B) were pretreated for 15 min with TSP-1 followed by 5 min for the respective drug or vehicle control (YC-1 10 µM, PPIX 100 µM, BAY 41-2272 10 µM, DEANO 1 µM). Cells were lysed and cGMP measured by ELISA. VSMCs were deprived of serum overnight prior to the assay. The data are expressed as mean ± SD (n= 4 VSMC, n= 3 platelets) in units of fold increase over control. *P < 0.05 versus non-TSP-1 pretreated. PPIX, meso-porphyrin IX; TSP-1, thrombospondin-1; VSMC, vascular smooth muscle cell.

Porcine VSMCs were seeded into collagen gels at 50 000 cells per well. Wells were treated with TSP-1 (2.2 nM) or left untreated for 12 h in basal media. The sGC activator drugs (100 µM YC-1, 10 µM BAY 41-2272, and 10 µM PPIX) or vehicle were added at the same time as contraction was initiated with 10% FCS. Contraction was measured as a function of change in gel area after 12 h at 37°C and 5% CO₂. Data are expressed as mean ± SD (n= 4). *P < 0.05 versus non-TSP-1 pretreated. PPIX, meso-porphyrin IX; TSP-1, thrombospondin-1; VSMC, vascular smooth muscle cell.