Portal de Periódicos da CAPES

MEASUREMENT OF THE SENSITIVITY OF THE SMALLEST BLOOD VESSELS IN HUMAN SKIN: RESPONSES TO GRADED MECHANICAL STIMULATION IN NORMAL MEN 1

1941; American Society for Clinical Investigation; Volume: 20; Issue: 4 Linguagem: Inglês

10.1172/jci101227

1558-8238

Joseph Palma, Samuel R. M. Reynolds, Frances I. Foster,

Thermoregulation and physiological responses

The physiological responses of the smallest blood vessels in human skin to mechanical and chemical stimuli have been the subject of numer- ous studies and several important monographs (1, 2, 3, and others).The qualitative aspects of the white and red reactions of the triple response have been well-defined and their localization to the smallest vessels has been established.Despite the extent of, and widespread interest in this subject, no attempt has been made until now to put these on a simple quantitative basis.Such experiments should enable an observer to measure the sensi- tivity of the skin capillaries in a subject from day to day, and to compare such data among a group of individuals.The present report offers one of two such methods which we have developed.The procedure usually employed experimentally to elicit the several components of the triple re- sponse are mechanical pressure and local infiltration (by pricking or iontophoresis) of vasodilator or vasoconstrictor drugs.The chemical methods have been used in a quasi-quantitative manner (4, 5, 6) but these tests depend upon a number of fac- tors which may only indirectly involve the sensi- tivity of the capillaries.Plethysmographic studies and measurements of skin temperature likewise fail to reflect the irritability of the smallest vessels (7, 8).The response of these vessels to graded mechanical stimulation offers, on the contrary, a direct approach to this problem.The technic de- scribed below depends upon this principle.Its ap- plication rests upon control of two qualities of a stimulus, namely, intensity and duration.Thus, if a true measure of the excitability of the vessels were obtained, a typical strength-duration curve like that found in determining the threshold of