Abstract
To investigate the nitric oxide synthase (NOS) and reactive oxygen species (ROS) contributions of the cutaneous vasodilator response to transient receptor potential ankyrin-1 channel (TRPA1) activation in young and older adults. In sixteen young (20±2years, 8 females) and sixteen older adults (61±5years, 8 females), cutaneous vascular conductance normalized to maximum vasodilation (%CVCmax) was assessed at four dorsal forearm skin sites continuously perfused via microdialysis with: 1) vehicle solution (Control, 2% dimethyl sulfoxide, 2% Ringer, 96% propylene glycol), 2) 10mM Ascorbate (non-specific ROS inhibitor), 3) 10mML-NAME (non-specific NOS inhibitor), or 4) Ascorbate+L-NAME. The TRPA1 agonist cinnamaldehyde was co-administered at all sites [0% (baseline), 2.9%, 8.8%, 26.4%; ≥ 30min per dose]. %CVCmax was not different between groups for Control, L-NAME, and Ascorbate (all p>0.05). However, there were significant main dose effects for each site wherein %CVCmax was greater than baseline from 2.9% to 26.4% cinnamaldehyde for Control and Ascorbate, and at 26.4% cinnamaldehyde for L-NAME and Ascorbate+L-NAME (all p<0.05). For Ascorbate+L-NAME, there was a significant main group effect, wherein perfusion was 6 %CVCmax [95% CI: 2, 11, p<0.05] greater in the older compared to the young group across all cinnamaldehyde doses. There was a significant main site effect for area under the curve wherein L-NAME and Ascorbate+L-NAME were lower than Control and Ascorbate across groups (all p<0.05). The NOS-dependent cutaneous vasodilator response to TRPA1 activation is maintained in older adults, with no detectable contribution of ascorbate-sensitive ROS in either age group.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have