Effects of chronic exercise and deconditioning on platelet function in women

Wang, Jong-Shyan, Chauying J. Jen, and Hsiun-Ing Chen.Effects of chronic exercise and deconditioning on plateletfunction in women. J. Appl. Physiol.83(6): 2080-2085, 1997.To investigate the effects of chronicexercise and deconditioning on platelet function in women, 16 healthysedentary women were divided into control and exercise groups. Theexercise group cycled on an ergometer at 50% maximal oxygenconsumption for 30 min/day, 5 days/wk, for two consecutive menstrualcycles and then were deconditioned for three menstrual cycles. Duringthis period, platelet adhesiveness on a fibrinogen-coated surface,ADP-induced platelet aggregation and intracellular calciumconcentration elevation, guanosine 3,5-cyclic monophosphate (cGMP) content in platelets, and plasma nitric oxide metabolite levels were measured before and immediately after a progressive exercise test in the midfollicular phase. Ourresults indicated that, after exercise training,1) resting heart rates and bloodpressures were reduced, and exercise performance was improved;2) resting platelet function wasdecreased, whereas plasma nitrite and nitrate levels and platelet cGMPcontents were enhanced; and 3) thepotentiation of platelet function by acute strenuous exercise wasdecreased, whereas the increases in plasma nitrite and nitrate levelsand platelet cGMP contents were enhanced by acuteexercise. Furthermore, deconditioning reversed these training effects. This implies that training-induced platelet functional changes in women in the midfollicular phase may be mediatedby nitric oxide.