Hypoxia gradually augments metabolic and thermoperceptual responsiveness to repeated whole‐body cold stress in humans

Aging augments renal vasoconstrictor response to orthostatic stress in humans.

The ability of the human body to maintain arterial blood pressure (BP) during orthostatic stress is determined by several reflex neural mechanisms. Renal vasoconstriction progressively increases during graded elevations in lower body negative pressure (LBNP). This sympathetically mediated response redistributes blood flow to the systemic circulation to maintain BP. However, how healthy aging af...

Hypoxia augments apnea-induced peripheral vasoconstriction in humans.

Obstructive apnea and voluntary breath holding are associated with transient increases in muscle sympathetic nerve activity (MSNA) and arterial pressure. The contribution of changes in blood flow relative to the contribution of changes in vascular resistance to the apnea-induced transient rise in arterial pressure is unclear. We measured heart rate, mean arterial blood pressure (MAP), MSNA (per...

Aging affects the cardiovascular responses to cold stress in humans.

Cardiovascular-related mortality peaks during cold winter months, particularly in older adults. Acute physiological responses, such as increases in blood pressure, in response to cold exposure may contribute to these associations. To determine whether the blood pressure-raising effect (pressor response) of non-internal body temperature-reducing cold stress is greater with age, we measured physi...

Respiratory and cardiovascular responses to cold stress following repeated cold water immersion.

The effects of cold acclimation (CA) on the cardiorespiratory responses to cold air and water stress tests (CST) were studied in 7 males before and after a CA program of daily 90-min cold water (18 degrees C) immersions repeated 5 times a wk for 5 consecutive wk. The CST consisted of a 90-min resting exposure to cold air (5 degrees C, 30% relative humidity) or water (18 degrees C) during which ...

Acclimatization to Cold in Humans