The effect of pre-cooling intensity on cooling efficiency and exercise performance

Although pre-cooling is known to enhance exercise performance, the optimal cooling intensity is unknown. We hypothesized that mild cooling opposed to strong cooling circumvents skin vasoconstriction and thermogenesis, and thus improves cooling efficiency reflected in improved time to exhaustion. Eight males undertook three randomized trials,...

Inspired Carbon Dioxide During Hypoxia: Effects on Task Performance and Cerebral Oxygen Saturation

Introduction: Exposure to a hypoxic environment has a deleterious effect on physiological and mental functions. We studied the effect of added inspired CO2 during artificially induced hypoxic normobaric hypoxia (oxygen saturation ∼80%) on complex task performance. Methods: In random order, 22 healthy volunteers were exposed to 3 gas mixtures for...

Cytoskeletal effects of Rho-like small guanine nucleotide-binding proteins in the vascular system

Rho-like small GTPases, with their main representatives (Rho, Rac, and Cdc42), have been recognized in the past decade as key regulators of the F-actin cytoskeleton. Rho-like small GTPases are now known to play a major role in vascular processes caused by changes in the actin cytoskeleton, such as smooth muscle cell contraction, endothelial...

Hyperoxia and local organ blood flow in the developing chick embryo

1. Hyperoxia can cause local vasoconstriction in adult animal organs as a protective mechanism against hyperoxia-induced toxicity. It is not known at what time during development this vasoconstrictor capacity is present. Therefore, we measured the cardiac output (GO) distribution in different organs during a period of acute hyperoxia (100% O2)...

Finapres tracking of systolic pressure and baroreflex sensitivity improved by waveform filtering

Objective. Arterial pressure waveforms distort between brachial and finger arteries, causing differences mainly in systolic pressure. Distortion, reportedly, can be removed by applying a waveform filter to the finger pressure. Design. We analysed the data from two studies that detected discrepancies in systolic tracking between Finapres and...

The isolated blood-perfused pig ear: An inexpensive and animal-saving model for skin penetration studies

To overcome most of the disadvantages of current models to investigate percutaneous penetration of drugs or toxic substances, a model is proposed here based on the isolated pig ear, which is obtained at the slaughterhouse, and perfused with oxygenated blood from the same pig. To determine the viability of the preparations, we measured glucose...

Pressure-diameter relationships of segments of human finger arteries

Pressure-diameter relationships of segments of human finger arteries, aged 57-85 years, were measured in vitro. The arteries, obtained at autopsy within 48 h after death, were stored in glucose-free Tyrode at 4 degrees C. Experiments began within 40 h after autopsy. The diameter responses to various transmural pressure changes, with and without...