A marked pressor response to water drinking has been observed in patients with autonomic failure and in the elderly, and has been attributed to sympathetic vasoconstrictor activation, despite the absence of such a pressor response in healthy subjects with intact sympathetic mechanisms. We investigated whether water drinking in normal subjects affected peripheral sympathetic neural discharge [...]
Under outdoor conditions this model was over estimating sweat loss response in shaded (low solar radiation) environments, and underestimating the response when solar radiation was high (open field areas). The present study was conducted in order to adjust the model to be applicable under outdoor environmental conditions. Four groups of fit acclimated subjects participated in [...]
The relationship among changes in thirst sensations, blood variables, and differential fluid intake in hypohydrated humans was examined. Seven subjects were hypohydrated by 0%, 3%, 5%, and 7% of their body weight on four separate trials which were systematically randomized between subjects. Hypohydration levels were achieved with a regimen of restricted food and fluid intake [...]
No abstract available.
To investigate the interaction between antidiuretic hormone (ADH) and renin-angiotensin system, plasma ADH and plasma renin activity (PRA) were determined in normal subjects (n = 10) under various hydrated states. Four experimental conditions, i.e., water loading, infusion of hypertonic saline, acute dehydration induced by furosemide and postural changes, were chosen. 1. Upright posture decreased plasma [...]
OBJECTIVE: The purpose of this study was to compare the effects of a water + electrolyte solution versus plain water on changes in drinking behaviors, hydration status, and body temperatures during wildfire suppression. METHODS: Eight participants consumed plain water, and eight participants consumed water plus an electrolyte additive during 15 hours of wildfire suppression. Participants [...]
No abstract available.
Dehydration is common in the elderly, and has been traditionally linked with salivary hypofunction. This study examined the effect of dehydration on parotid salivary flow rates. Twelve young and 12 older healthy subjects abstained from food and fluid intake for 24 hrs (dehydration) and then underwent i.v. rehydration proportional to the amount of weight lost. [...]
Dehydration can affect brain structure which has important implications for human health. In this study, we measured regional changes in brain structure following acute dehydration. Healthy volunteers received a structural MRI scan before and after an intensive 90-min thermal-exercise dehydration protocol. We used two techniques to determine changes in brain structure: a manual point counting [...]