Prolonged or repeated exposure to cold conditions can induce NFCI; Afro-Caribbeans are more susceptible than white Caucasians. We compared in Caucasian and Asian males (20-22 years, n=6), responses evoked by 3 immersions of the right leg in water at 15°C for 10 min with 10-min intervals, the left leg was ~horizontal. In Caucasians, cutaneous red cell flux in right foot (rRCF) fell from 12.8±2.4 to 11.6±1.3, 9.2±1.6* and 8.6±1.5PU in immersions 1, 2 and 3 with some recovery to11.3±2.4, 9.7±2.3* and 9.6±1.6* PU (*: P<0.05 vs baseline). By contrast, in Asians, rRCF fell from 11.1±2.4 to as low as 7.0±0.9*, 6.3±0.8* and 5.8±0.7*PU, with no recovery: 6.8±0.8*, 6.6±0.8*, 6.8±0.7*PU. Caucasians showed no change in contralateral left RCF whereas in Asians, left RCF fell from 25.3±4.2 to 20.1±0.0.9, 20.4±2.8 and 20.5±0.7PU. After COX inhibition (aspirin; 600mg p.o), rRCF fell from 18.0±4.8 to 13.6±4.9*, 11.8±3.7* and 10.9±3.8* during 1st, 2nd and 3rd immersions in Caucasians, with no recovery: 13.5±4.0*, 13.2±4.7* and 11.7±4.0* PU. In Asians, rRCF fell from 7.7±0.9 to 5.9±0.7*, 5.6±0.6* and 5.8±0.6* PU, with no recovery: 5.8±0.9*, 5.6±0.7* and 5.6±0.7*PU. We suggest that young Asians show greater and more persistent local and reflex cutaneous vasoconstrictor responses to cool water immersion than Caucasians and so may be more vulnerable to NFCI; vasodilator COX products may limit cold-induced vasoconstriction in Caucasians.
|Publication status||Published - 2014|
|Event||Annual Main Meeting of the Society for Experimental Biology - Convention Center, San Diego, United States|
Duration: 26 Apr 2014 → 30 Apr 2014
|Conference||Annual Main Meeting of the Society for Experimental Biology|
|Period||26/04/14 → 30/04/14|