Vigorous exercise acutely changes platelet and B-lymphocyte CD39 expression

Abstract

. Vigorous exercise acutely changes platelet and B-lymphocyte CD39 expression. J Appl Physiol 98: 1414 -1419, 2005; doi:10.1152/japplphysiol.00315.2004.-CD39/ATP diphosphohydrolase is expressed on B lymphocytes, cytotoxic T lymphocytes, monocytes, platelets, and endothelial cells, and it has a critical role in the inhibition of platelet responsiveness. To determine whether strenuous exercise could acutely change expression of CD39 in platelets and lymphocytes, eight healthy sedentary men, 34 yr old (SD 7), and eight physically active men, 34 yr old (SD 6), performed graded upright cycle ergometry to volitional exhaustion. Blood samples collected both at baseline and after exercise test were employed to measure CD39 expression in platelets and lymphocytes. The percentage of circulating platelet-platelet aggregates, the "in vitro" ADP and collagen-induced platelet aggregation, and the expression of both platelet glycoprotein IIb-IIIa (PAC-1) and Pselectin (CD62) were also considered markers of platelet activation. After strenuous exercise, all subjects demonstrated significant platelet activation as judged by the increased percentage of platelet-platelet aggregates. The in vitro ADP-induced platelet aggregation and the expression of CD62P on ADP-stimulated platelets significantly increased in sedentary but not in active subjects. After exercise, all of the subjects showed a significant reduction of CD39 expression in platelet [sedentary: from 2.2 (SD 0.8) to 1.1% (SD 0.8), P ϭ 0.008; active: from 0.6 (SD 0.2) to 0.35% (SD 0.1), P ϭ 0.009] and an increase of CD39 expression in B lymphocytes [sedentary: from 47 (SD 13) to 60% (SD 11), P ϭ 0.0039; active: from 46 (SD 11) to 59% (SD 11), P ϭ 0.0038]. Taken together, these findings confirm the critical role of this ADPase in inhibition of platelet responsiveness, also suggesting a possible role of B lymphocytes in thromboregulation mechanism. sedentary men; active men; thromboregulation IN EPIDEMIOLOGICAL studies, moderate and vigorous exercise have been associated with a decrease in the risk of cardiovascular disease (1,16,27,41). However, vigorous exercise can acutely and transiently increase the risk of myocardial infarction and cardiac death, especially in sedentary subjects and in those with coronary heart disease (15, 31, 37, 43). The mechanism by which exercise triggers an acute cardiac event is not entirely known, although coronary thrombosis plays a key role. Several reports have demonstrated that strenuous exercise induces platelet activation, thus increasing thrombotic tendency (5,22,25,33,34). Various mechanisms, including increased plasma levels of norepinephrine and epinephrine (36), altered response of platelet ␣ 2 -adrenergic receptors (39), and impaired sensitivity of platelets to nitric oxide (NO) (34), have been hypothesized to explain both the increased platelet activation and reactivity after strenuous exercise. The role of hemoconcentration induced by acute exercise also has been considered (8, 40). The epidemiology of coronary artery disease indi...

CD39 activity correlates with stage and inhibits platelet reactivity in chronic lymphocytic leukemia

“…Variation of the ADPase:ATPase ratio has been observed between individuals, although intra-personal variation has not yet been observed. Although very low levels of CD39 expression on platelets has been reported [23,24], our laboratory found no difference between ATPase and ADPase activity in platelet-rich and platelet-poor plasma. This suggests that the contribution of platelet CD39 is minimal to non-existent and that leukocyte and endothelial cell CD39 exert primary control of ATP and ADP conversion to ADP and AMP (unpublished data).…”

Intravascular ADP and soluble nucleotidases contribute to acute prothrombotic state during vigorous exercise in humans

“…6), although the basal NTPDase was higher than in trained athletes. Probably, the thromboregulatory role of soluble NTPDase is even more relevant for patient populations who display the increased platelet aggregability at rest and especially during exercise, and in addition suffer from endothelial dysfunction and insufficient release of antiplatelet compounds (El‐Sayed, 2002; Coppola et al 2005).…”

“…Among cellular elements of the blood, the leucocytes, but not erythrocytes and platelets, contribute to the catabolism of nucleotides (Coade & Pearson, 1989; Heptinstall et al 2005). Notably, flow cytometric analysis of venous blood from physically active men showed moderate exercise‐mediated increase in CD39 expression on B‐lymphocytes (from 46 ± 11 to 59 ± 11%, respectively) (Coppola et al 2005). Vascular NTPDase can be diminished under conditions of inflammation or oxidant stress, thereby causing profound shifts in vascular permeability and local procoagulant responses (Robson et al 2005).…”

Effects of Physical (In)activity on Platelet Function

“…Nevertheless, increased platelet aggregation in response to exercise was observed by light transmission aggregometry without [ 11 , 15 , 29 – 32 ] and after adjustment of platelet count in platelet-rich plasma (PRP) [ 21 , 33 , 34 ], but also with other techniques including electrical impedance aggregometry [ 13 , 35 – 41 ], filtragometry [ 42 – 44 ], calculation of reduction of single (unaggregated) platelets after agonist stimulation [ 45 – 50 ], and platelet aggregation after application of shear stress by a rotational viscometer [ 20 , 51 , 52 ]. Notably, this observed increase of in vitro platelet aggregation after acute exercise is not in contrast to those studies that found no effects of exercise on GPIIb/IIIa activation, as platelet aggregation rather depends on sensitivity of platelets towards agonists than on the basal activation state of glycoprotein IIb/IIIa.…”

“…The influence of acute exercise on the expression of P-selectin on platelets has been addressed by several studies and yielded contradictory results. Basal P-selectin expression (i.e., without intentional platelet stimulation applied ex vivo) has been found to be increased [ 17 , 42 , 44 , 64 – 68 ] after acute exercise, although this was not in all studies statistically significant [ 13 , 18 , 21 ]. Notably, several studies found no influence of exercise on basal P-selectin expression [ 11 , 19 , 22 , 69 – 71 ].…”