Cutaneous vascular responses in finger and forearm during rising ambient temperatures

Abstract

During slowly rising ambient temperatures, digital vasodilatation often preceded that in forearm skin; the two vasodilatations proceeded together in spring but not in summer experiments. The curvilinear relation of local skin temperature to local skin blood flow in the forearm often showed an abrupt inflection, suggesting the appearance of an additional influence on the vessels; however, a regular relation to local sweating was not apparent, vasodilatation in forearm skin often continued to increase even when local skin temperature had stabilized or fallen slightly, and the forearm vascular events were prevented by local cooling. During repeat cycles of ambient temperature, complete dissociation of the cutaneous vascular events in finger and forearm and of forearm vasodilatation and sweating often occurred. Digital vasomotor waves were not accompanied by similar waves in forearm skin. Of multiple factors possibly controlling the forearm skin circulation, the local temperature seemed most important. The maximum vasodilatation in forearm during heat exposure was not augmented by acetyl-β-methylcholine. Submitted on January 18, 1960

Sustained increases in skin blood flow are not a prerequisite to initiate sweating during passive heat exposure

“…A few studies have considered the relationship between SkBF and sweating during physiologically relevant conditions by examining the onset threshold of both responses when they are allowed to increase normally during heat exposure. With the use of this approach, early studies provide conflicting evidence with some reporting that SkBF increases before (40,41), after (24), or simultaneously (45) with the increase in sweat production. Most recently, Smith et al (42) examined whether differences in local SkBF could explain regional differences in LSR.…”

“…Most recently, Smith et al (42) reported that the onset threshold for SkBF precedes the one for sweat rate and suggested that an increase in SkBF may be required to initiate sweat production during whole body passive heat stress. Other studies have provided conflicting evidence that SkBF increases before (40,41), after (24), or simultaneously (45) with sweat production. However, these studies did not manipulate one heat loss response to observe if parallel changes are observed in the other.…”

Die Rolle der Schweiβ-Sekretion beim atopischen Ekzem im Kindesalter

“…Diese chronisch provozierte sudomotorische A ktivität, kann bestim m t eine ganze Menge von biologischen Vorgängen in Gang setzen (zum Bei spiel Freilassung von verschiedenen Vasoaktiven-und Perm eabilitäts faktoren, wie Kinine usw. [38,39,40,41], die zu dem für die atopischen Kinder nach dem Schwitzen so typischen Juckreiz führen [42,43,44,45]. Dieser Juckreiz wird von manchen Autoren für das prim äre Ge schehen gehalten.…”