Role of Metabolic Inhibitors on the Adhesion of Rabbit Gel Filtered Platelets to Collagen - Sepharose

Abstract

The adhesion of rabbit gel filtered platelets (GFP) to collagen-Sepharose was found to be largely energy independent, since metabolic inhibitors only partially suppressed this process. 51Cr and 14C-serotonin labeled GFP were incubated at 37°C/10 min. with anti-metabolites prior to passage over collagen-Sepharose columns. Adhesion and release responses were determined by 51Cr content of columns and 14C content of the supernatant from column eluents. Antimycin-A (AA, 2μg/ml), or AA plus 2-deoxy-D-glucose (2DG, 32mM) or Rotenone (R, 2μg/ml) produced small reductions in adhesion. All three compounds inhibited release, their effects being additive. 2DG or glucono-§-lactone (GLAC, 10mM) alone had little or no effect on adhesion. 2DG reduced release response by 40%, while GLAC had no effect. AA or R reduced adhesion by 35% and 31%, and release by 51% and 47%, respectively. The combination of 2DG, GLAC, AA and R did not reduce adhesion more than 45%. The Inhibitory effects of AA were time and dose related, and the addition c glucose (0.1%) circumvented these effects. These experiments suggest that adhesion includes energy dependent and independent phases. In addition, spherical platelets (GFP at 4°c/24 hrs.) also adhered to collagen-Sepharose; however, in contrast to disc-platelets (GFP at 37°c/10 min.), the adhering platelets demonstrated a depressed release response (-79%),