Effect of acute smoking on red blood cell deformability in healthy young and elderly non-smokers, and effect of verapamil on age- and acute smoking-induced change in red blood cell deformability.

The effects of age and acute smoking on red blood cell (RBC) deformability in non-smokers have been studied. RBC ATP levels and in vitro effects of verapamil on pre- and post-smoking filterabilities have been determined in an attempt to make an approach to the mechanism(s) responsible for the effect of age and acute smoking on RBC deformability. Nine young and nine elderly healthy non-smokers volunteered to the study. Venous blood samples obtained before and after the smoking of one cigarette, were used for ATP analysis and RBC deformability determination. ATP was determined enzymatically, deformability was assessed by gravity driven microfiltration technique. Verapamil was added to pre- and post-smoking blood samples to yield a final concentration of 1 mg-1. RBC deformability was found to decrease in the elderly group by 19.1% of that of the young group (p < 0.001). Acute smoking decreased the filterabilities of RBCs by 15.3% (p < 0.0001) and 15.9% (p < 0.001) of their pre-smoking values in the young and the elderly groups respectively. The smoking-induced decreases in RBC deformability were found to be associated with slight but significant decreases (p < 0.02 and p < 0.005 for the young and the elderly group respectively) in RBC ATP concentrations. Ca2+ channel blockade with verapamil did not produce any significant change in pre- and post-smoking filterabilities of RBCs from the young group, but improved these variables by 9.7% (p < 0.005) and 10.7% (p < 0.05) in the elderly group. In conclusion age and smoking are two independent factors that affect the deformability of human RBCs.(ABSTRACT TRUNCATED AT 250 WORDS)