Temperature sensitivity of skeletal muscle in the conscious goat

Abstract

A method has been developed to test the hypothesis that the deep tissues of the legs, e.g., skeletal muscle and/or periosteum, contain thermosensitive elements feeding signals into the temperature-regulating system. Stainless steel thermodes of 10 to 12-mm diameter and 100 to 150-mm length were chronically implanted into the marrow spaces of both humeri and femora, all of which have wide cavities and thin walls. Perfusing the thermodes with water of 0 degree C altered the temperature of the deep muscle layers by several degrees. The animals were further equipped with intravascular heat exchangers, which served to keep general body temperature constant during periods of leg cooling. Eighty experiments were performed in a hot and dry environment. During the middle period of each experiment the legs were cooled by perfusing the thermodes with water of 0 degree C. This caused respiratory evaporative heat loss to decrease by 0.15-0.20 W/kg. The small but significant response occurred at constant general body temperature and is therefore indicative of a local effect of the cooling on deep thermosensitive elements in the legs themselves and a neural afferent transmission of temperature signals into the temperature-regulating system.

Ischaemia in working muscles potentiates the exercise‐induced sweating response in man

“…That under certain circumstances, whole body heat dissipation may be regulated by intramuscular thermosensors is also supported by the observation that selective cooling of skeletal muscle leads to diminished overall heat dissipation in experimental animals (Jessen et al. 1983).…”

Heat of sorption induced by sweating affects thermoregulatory responses during heat load

“…However, it has been suggested that thermal inputs to the thermoregulatory centre could be aected by input from muscle thermoreceptors as well as skin and core thermoreceptors (Jessen et al 1983;Werner and Heising 1989). Since our subjects were given passive heat stress and they did not exercise, their muscles were hardly positively stimulated.…”

The metabolic response to skin temperature

“…Recent evidence suggests that thermal afferents of temperature regulating system originate also in skeletal muscle (Jessen et al 1983;Mense and Meyer 1985), and it appears conceivable that the afferent input via these fibers increased at low skin temperature. The relationship between skin temperature and MR at constant TcoRE as described by our experiments appears then as the result of a complex interaction of several factors, including the temperature-response relationship of skin thermoreceptors, an additional neuronal input generated in the skeletal muscle, and an unspecific temperature effect on muscle metabolism.…”