Effect of Histamine on Post-Exercise Capillary Permeability
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Date
2019
Authors
Edwards, Chaucie Kate
Journal Title
Journal ISSN
Volume Title
Publisher
University of Oregon
Abstract
Histamine, an endogenously released molecule in immune and inflammatory responses increases local vasodilation, blood flow, and capillary permeability. During exercise, histamine is produced within exercising muscle and contributes to an elevated post-exercise blood flow. The histamine-induced post-exercise vasodilation is contained within previously exercised muscle. It is unknown if intramuscular histamine also contributes to elevate capillary permeability following exercise. This study compared capillary permeability of the leg before and after prolonged unilateral knee-extension exercise under normal conditions and when histaminergic signaling was blocked. It was hypothesized that H1/H2 receptor antagonists would decrease capillary permeability following exercise in an exercised leg but not in a resting leg. Ten (2F) volunteers performed 60 min of unilateral knee-extension exercise at 60% of peak power after consuming either Placebo or histamine (H1/H2) receptor antagonists (Blockade). A capillary filtration coefficient (CFC) reflecting the rate of change in limb girth per rise in venous pressure was calculated using venous occlusion plethysmography. CFC was calculated prior to and following exercise in both the Exercise Leg and the Rest Leg. Data were analyzed with a 3-way RM ANOVA and presented as Means±SEM. Under Placebo conditions, there was no difference in pre-exercise CFC in the Exercise Leg or the Rest Leg (1.4±0.4 vs. 1.3±0.3 μg·100g-1·min-1·mmHg-1). Post-exercise CFC was greater in the Exercise Leg than the Rest Leg, P<0.05 (2.7±0.7 vs 1.4±0.3 μg·100g-1·min-1·mmHg-1). CFC increased in the Exercise Leg from pre to post-exercise by 120±25% (P<0.05) but did not increase in the Rest Leg (P=0.732). Under Blockade conditions, there was no difference in pre-exercise CFC in the Exercise Leg or the Rest Leg (1.7±0.5 vs. 1.3±0.5 μg·100g-1·min-1·mmHg-1). Post-exercise CFC did not differ in the Exercise Leg compared to the Rest Leg (1.8±0.5 vs. 1.1±0.4 μg·100g-1·min-1·mmHg-1). CFC did not increase in the Exercise Leg (P=0.608) or the Rest Leg (P=0.295) from pre to post-exercise.
Description
36 pages
Keywords
Human Physiology, Capillary Permeability, Exercise, Histamine, Recovery, Vasodilation