Increased Skin Blood Flow and Enhanced Heat Loss in Humans after Niacin Ingestion

Abstract

Healthy, young subjects were studied in three separate series of studies characterizing nicotinic acid (NA) ingestion (5 mg.kg-1). (1) At rest, seated (T. - 30 deg C, rh = 23%) at 0800 h and again between 1800 and 2100 h. (2) At rest (R) and during seated exercise (X, Ta = 29 deg C, rh = 30%). (3) During upright exercise when wearing a protective clothing system (Ta = 28 deg C, rh = 30%). NA treatment resulted in decreased Tes, T.sk, SKBF, FBF, heart rate, and cutaneous vascular conductance (CVC) (P<0.05). NA decreased mean arterial pressure at rest. Subjects had no difficulty completing, seated or upright exercise in either control or NA experiments. The pharmacological manipulation of skin blood flow at rest and during moderate exercise effectively increased sensible heat flux during seated as well as upright exercise. NA ingestion also increased sensible heat flux from individuals dressed in chemical protective clothing. These experiments show that pharmacologic manipulation of skin blood flow by NA ingestion should be done cautiously, especially when NA will be used repeatedly or in novel circumstances. Niacin, Heat exchange, Cardiovascular responses, Skin blood flow.

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Document Details

Document Type
Technical Report
Publication Date
Jun 01, 1994
Accession Number
ADA281124

Entities

People

  • Lou A. Stephenson
  • Margaret A. Kolka

Organizations

  • United States Army Research Institute of Environmental Medicine

Tags

Communities of Interest

  • Biomedical

DTIC Thesaurus Topics

  • Blood
  • Blood Vessels
  • Body Temperature
  • Cardiovascular Diseases
  • Cardiovascular Physiological Phenomena
  • Cardiovascular System
  • Chemistry
  • Circadian Rhythms
  • Health Services
  • Heart Rate
  • Heat Transfer
  • Medical Personnel
  • Metabolic Diseases
  • Military Research
  • Physiology
  • Protective Clothing

Fields of Study

  • Biology

Readers

  • Cardiovascular Physiology
  • Exercise and Sports Science.