Abstract
Hemodynamic mechanisms of blood pressure elevation during the cold pressor test (CPT) were investigated in relation to its pain and cold stimulus components. Fourteen normotensive college male students underwent two, 90-s CPT's (VC and 8°C) in a counter-balanced order; and ten others underwent a 90-s CPT with a very mild temperature (14°C). The results indicated that a primary increase in peripheral vascular resistance, as well as a secondary increase in heart rate, raised blood pressure during the CPT's with VC and 8°C, whereas only an increase in peripheral vascular resistance was effective in raising blood pressure in the 14°C CPT. These suggested that both the pain and cold stimulus components affected the blood pressure elevations during the former and solely the pain component seemed to play a predominat role in the latter. Baroreceptor reflex sensitivity was unchanged during any of the CPT's : This suggested that only “resetting” occurred against the blood pressure elevations. The implications of these results were discussed for a better understanding of stress testing in cardiovascular research.
