W Kenney

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..m(-2). Torr(-1) at 36 degrees C) and women (17.7 W. m(-2). Torr(-1) at 36 degrees C and 15.5 W. m(-2). Torr(-1) at 38 degrees C) and may be used to model heat balance responses for unacclimated men and women working in hot environments...

..Children rarely exhibit voluntary dehydration for activities lasting 45 min or less; however, drink flavoring and sodium chloride are important promoters of drinking in active children...

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..In conclusion, when athletes maintain or lose BM, changes in S([Na+]) can be accurately predicted by changes in the mass balance of fluid, Na(+), and K(+) during prolonged running in the heat...

..BT completely blocked VC in both age groups. Cutaneous VC in young subjects is mediated by both NA and sympathetic cotransmitter(s); however, reflex VC in aged skin is attenuated compared to young and appears to be mediated solely by NA...

..05) than in NT. Antioxidant supplementation alone or combined with arginase inhibition augments attenuated reflex cutaneous VD in hypertensive skin through NO- and non-NO-dependent mechanisms...

..35 +/- 3%, P < 0.05). Although its magnitude remains unaffected, cold-induced VC becomes less dependent on adrenergic and more dependent on Rho kinase signaling with advancing age...

..To determine the effect of 1, 2, 3, and 4% dehydration (DEH) versus euhydration (EUH) on basketball performance in adult male players...

..To determine the effects of dehydration (DEH) on attentional vigilance in male basketball players...

..This article highlights recent findings of how age-related vascular impairments in NO signaling contribute to attenuated cutaneous vasodilation...

..05). Reduced NOS3 substrate availability through upregulated arginase contributes to cutaneous microvascular dysfunction in hyperocholesterolaemic humans, which is corrected with atorvastatin therapy...

..This mechanistic review highlights some of the recent findings in the area of aging and the thermoregulatory control of skin blood flow...

..001). ASA-induced COX and specific platelet ADP receptor inhibition attenuate reflex vasodilation, suggesting platelet involvement in reflex vasodilation through the release of vasodilating factors...

..These data are consistent with the concept that reduced bioavailability of BH(4) and/or tyrosine may impair noradrenaline synthesis and contribute to the attenuated vasoconstrictor response in aged skin...

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..01). Cumulatively, these data indicate that reflex VC is more reliant on ROCK in aged skin such that approximately half of the total VC response to whole body cooling is ROCK dependent...

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..Local BH(4) supplementation augments reflex and tyramine-induced VC in aged skin, suggesting that reduced BH(4) bioavailability may contribute to attenuated VC during whole-body cooling...

..To determine the degree of natural acclimatization and artificially induced acclimation-related changes during repeated exercise in the heat bouts in seven lean and seven obese 9- to 12-yr-old boys during summer months...

..001). This is the first observation that chronic low-dose aspirin therapy attenuates reflex cutaneous vasodilation through both COX- and NOS-dependent mechanisms...

..Vasodilatation is attenuated with HTN due to decreased NO-dependent vasodilatation and can be augmented with arginase inhibition but not L-arg supplementation, suggesting that arginase is up-regulated with HTN...

..05). The DeltaT(mid) did not account for the drop in T(es) in OS. Healthy aged humans failed to maintain T(es); however, the mechanisms underlying this response are not clear...

..However, older skin does not display enhanced VC capacity until treated with saturating doses of NA, possibly due to age-associated decrements in Ca2+ availability or alpha2C-adrenoceptor function...

..The results indicate that the area of vasodilation and CVC within the vasodilated area are reduced in aged skin during early passive heating, but only CVC is reduced at DeltaT(es) = 0.8 degrees C...

..These results suggest impaired CSPA function in aged skin and age-specific differences in the ability of sensory nerves to modify local inflammatory SkBF responses...

..In summary, CSPA activity contributes modestly to the overall SkBF response to local heating in an age-specific manner...

..Furthermore, the forearm vasoconstriction elicited by LBNP in older men reflects that of underlying tissue (i.e., muscle) rather than that of skin, whereas -30 mmHg LBNP also decreases SkBF in young hyperthermic men...

..001 both groups). ACh mediates cutaneous VD through prostanoid and non-NO-, non-prostanoid-dependent pathways. Further, older subjects have a diminished prostanoid contribution to ACh-mediated VD...

..Considering that NE is the only functional neurotransmitter mediating reflex VC in aged skin, attenuated NE-mediated VC may further predispose older humans to excess heat loss in the cold...

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..001). Acute Asc supplementation increased reflex VD in aged skin. Asc combined with arginase inhibition resulted in a further increase in VD above Asc alone, effectively restoring CVC to the level of young subjects...

..14-42% in young subjects), possibly due to varying rates of physiological aging. These results suggest that the relative influence of individual characteristics changes with aging...

..05 versus C). Increasing L-Arg for NO synthesis by either arginase inhibition or direct L-Arg supplementation restores the age-related deficit in reflex cutaneous vasodilatation...

..This study compared the voluntary fluid intake behavior of older men and women (54-70 yr) when provided cold, palatable beverages and ample opportunity to drink between repeated bouts of exercise in the heat...

..76, which is indicative of excellent reliability between methods. Measuring pre- to post-exercise DeltaBM is an accurate and reliable method to assess the DeltaTBW...

..03), after stratifying by progestin intake. These results support the concept that basal body temperature is regulated by a network of endocrine and immune mediators that are significantly influenced by age...

..022) and an HRT/IL-6 interaction with CRP (P =0.016) indicated more complex relationships between hormone replacement, cytokine activity, and health risks associated with menopause...

..PSI evaluation was extended for men and women of different ages (50-70 yr) during acute EHS, heat acclimation, after aerobic training, and inclusive of women undergoing hormone replacement therapy...

..O: 38 +/- 5%CVCmax; P < 0.05). These data suggest that age-related changes in both axon reflex-mediated and NO-mediated vasodilation contribute to attenuated cutaneous vasodilator responses in the elderly...

..The thermal and evaporative resistance data presented in this paper can be used in the solution of heat balance equations to predict physiological responses of football players...

..This suggests that attenuated cutaneous vasodilation with age may be due to a reduction in, or decreased vascular responsiveness to, the unknown neurotransmitter(s) mediating AVD...

..This paper describes select environmental conditions and physiological responses of three runners attempting to run across the entire Sahara desert over a 111-d period...

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..Specific Aim 4 examines the mechanisms investigated in Aims 1-3 before and after a statin therapy intervention with atrovastatin. ..

..Data from this last proposed investigation operationalizes the SkBF decrement to allow policy-making by health organizations and for modeling biophysical and physiological responses of the elderly to extreme environments. ..

..It is hypothesized that: 1) hydration will increase cardiac output; and 2) hydration with a commercially available sports drink will be better than hydration with water. ..

..We plan to compare older and younger men and women to examine the mechanism by which aging attenuates reflex active cutaneous vasodillation. ..

..To examine the effect of age on these responses, seven young and seven older men were head-up tilted in a thermoneutral environment and wearing water-perfused suits. ..

..Furthermore, results from these studies may provide an oral intervention strategy to functionally improve impaired cutaneous vasoreactivity in the aged during thermal stress. ..

..Specific Aim 4 examines the mechanisms investigated in Aims 1-3 before and after a statin therapy intervention with atrovastatin. ..

..Specific Aim 4 examines the mechanisms investigated in Aims 1-3 before and after a statin therapy intervention with atrovastatin. ..

..Therefore, the proposed studies under Specific Aim 4 will include differences in muscle mass within age groups. ..

..We plan to compare older and younger men and women to examine the mechanism by which aging attenuates reflex active cutaneous vasodillation. ..

..Most of the participants have completed both pre- and post-testing. In the future, we may invite some participants back to study the effects of de-training on skin blood flow. ..

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..Four more experimental trials are necessary for completion of Phase III. We expect to complete this phase by April, 1998. ..

..Furthermore, results from these studies may provide an oral intervention strategy to functionally improve impaired cutaneous vasoreactivity in the aged during thermal stress. ..