Effects Of Aspirin On Catecholamine Responses Of Males During Acute Cold Exposure

Abstract

INTRODUCTION: Previous research (Larsson et al. 1994) has suggested that aspirin may be less effective as an antithrombotic drug during sympathoadrenal activation in humans, however Kahawara et al. (1989) reported that an increase in plasma noradrenaline was significantly correlated with the change in platelet aggregation and suggested that the cold-related increase in sympathetic nervous activity may contribute to the enhancement of platelet function. PURPOSE: To examine the effect of aspirin ingestion on catecholamine responses during exposure to 12°C air for a period of 120-minutes. METHODS: Seven (7) young males were fed a placebo (PL), a low dose of aspirin (ASA-L: 81 mg. d-1) or a high dose of aspirin (ASA-H: 650 mg.d-1) for one week prior to each experimental trial. Following a baseline period (30-minutes), subjects were moved into an environmental chamber where they remained seated and still for 120-minutes, or until core temperature (Tre) was < 35°C. Antecubital venous blood samples were drawn at the completion of baseline and at 60 and 120-minutes of exposure for measurement of epinephrine (EPI) and norepinephrine (NE). RESULTS: ANOVA revealed EPI concentration did not demonstrate a significant (p<0.05) main effect for treatment or treatment-by-time interaction. However, EPI did demonstrate a significant main effect for time, with differences demonstrated between baseline and 60 minutes and baseline and 120 minutes. NE concentration did not demonstrate a significant main effect for treatment or a treatment-by-time interaction in the present investigation. CONCLUSION: These data demonstrate that aspirin had no significant effect on the sympathetic nervous system response induced by acute cold exposure with respect to the hormonal parameters measured.