The potent platelet inhibitory effects of S-nitrosated albumin coating of artificial surfaces.
OBJECTIVE
We studied the antithrombotic effect of coating glass, collagen and metal stent surfaces with bovine serum albumin (BSA) covalently modified to carry S-NO functional groups denoted (pS-NO-BSA).


METHODS
Video-enhanced light microscopy was used to visualize canine blood platelet adhesion and aggregation in a parallel plate glass chamber. Platelet adhesion was observed for 60 min on glass, glass coated with BSA, glass coated with pS-NO-BSA, collagen I (CO) surface, CO coated with BSA and CO coated with pS-NO-BSA. We also coated Palmaz-Shatz (P-S) stents with pS-NO-BSA. Coated and uncoated stents were then immersed in porcine platelet-rich plasma for two min and the platelet cyclic GMP level was measured. In six anesthetized pigs, coated and uncoated stents were placed in the carotid arteries and [111In]-labeled platelets were circulated for 2 h. The stented arteries were then removed and placed in a gamma well counter.


RESULTS
There was significantly less platelet attachment, adhesion and aggregation on the pS-NO-BSA coated surfaces compared with the BSA coated and uncoated surfaces. The pS-NO-BSA coating increased the platelet cGMP levels to 5.9+/-0.7 pmoles/10(8) platelets compared with 2.7+/-0.9 pmoles/10(8) platelets for control (p < 0.01). The average gamma ray count from [111In]-labeled platelets that attached to the coated stents was 90,000+/-42,000/min and 435,000+/-290,000/min for the uncoated stents (p < 0.01).


CONCLUSIONS
The pS-NO-BSA coating of thrombogenic surfaces reduces platelet adhesion and aggregation, possibly by increasing the platelet cGMP. This inhibitory effect appears to be a consequence of the direct antiplatelet actions of NO combined with the antiadhesive properties of albumin.
Maalej
N
N
University of Wisconsin Medical School, Madison 53792, USA.
Albrecht
R
R
Loscalzo
J
J
Folts
J D
JD
D000818:Animals; D001792:Blood Platelets / Q000187:drug effects* / Q000502:physiology; D001807:Blood Vessel Prosthesis; D002417:Cattle; D020099:Coated Materials, Biocompatible; D003094:Collagen; D006152:Cyclic GMP / Q000378:metabolism; D004285:Dogs; D006801:Humans; D008954:Models, Biological; D009566:Nitrates / Q000494:pharmacology*; D015538:Nitrosation; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology*; D012710:Serum Albumin, Bovine / Q000378:metabolism*; D015607:Stents; D013552:Swine; D014741:Video Recording
D020099:Coated Materials, Biocompatible; D009566:Nitrates; D010975:Platelet Aggregation Inhibitors; D012710:Serum Albumin, Bovine; D003094:Collagen; D006152:Cyclic GMP