Accession Number:

ADA209752

Title:

Cardiovascular and Thermoregulatory Effects of Niacin

Descriptive Note:

Corporate Author:

ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA

Report Date:

1989-05-01

Pagination or Media Count:

8.0

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 niacinkg 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.

Subject Categories:

  • Biochemistry
  • Stress Physiology
  • Pharmacology

Distribution Statement:

APPROVED FOR PUBLIC RELEASE