Cardiovascular and Thermoregulatory Effects of Niacin
Abstract
The purpose of the study was to investigate thermoregulatory and cardiovascular effects of the vasodilatory agent, niacin. Four subjects were studied during rest in a moderately warm environment. Esophageal (Tes) and skin temperature, forearm blood flow and sweating rate was measured frequently. After control data were obtained, 5 mg niacin/kg body weight were ingested. Skin temperature increased approximately 15 min. after ingestion of the drug, beginning on the the head and torso, then spreading caudally. Forearm blood flow, as assessed by venous occlusion plethysmography, increased dramatically. These data indicate that the cutaneous vasodilatory action of niacin is sufficient to increase markedly dry heat loss in humans resting in a moderately warm environment. In a moderately warm environment, there was a substantial decrease in Tes; however,in cool or cold environments, dry heat loss would be even larger than observed in this study and the risk of hypothermia great. Any beneficial effect of niacin as a thermoregulatory aid in humans in a moderately warm environment must be balanced against the cardiovascular consequences (increased heart rate and decreased mean arterial pressure) of general cutaneous vasodilation.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1989
- Accession Number
- ADA209752
Entities
People
- Lou A. Stephenson
- Margaret A. Kolka
Organizations
- United States Army Research Institute of Environmental Medicine