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Abstract

Experiments on rats with hereditary stress-induced arterial hypertension showed that hypertension shortened the latency and increased the amplitude of constrictive reaction of skin blood vessels to rapid cooling characterized by more rapid and considerable increase in blood norepinephrine content compared to slow cooling. Decreased thermal threshold of metabolic reaction suggests that arterial hypertension is accompanied by changes in both the vascular walls and tissues involved in metabolic reaction to cooling.

Mechanisms of Modulation of Thermoregulatory Reactions during Cooling in Hypertensive Rats by the Sympathetic Nervous System

“…2), which confi rms our previous data [6]. Verapamil decreased temperature threshold for metabolic response to fast cooling, which was seen from threshold rectal temperature decrease (Fig.…”

“…The increase in peak shivering magnitude during cooling after administration of β-adrenoceptor blocker partially compensates inhibition of non-shivering thermogenesis. As it was mentioned previously [6], blockade of adrenoreceptors of one type during cooling in the whole organism is associated with intensifi cation of thermogenesis, media ted by adrenoreceptors of another type. However, it should be noted that compensatory properties of thermogenesis controlled by α 1 -and β-adrenoreceptors are limited in hypertensive rats in comparison with normotensive ones under conditions of inhibition of both shivering and non-shivering thermogenesis.…”

“…This in turn can affect body reactions to thermal infl uences mediated by these structures. We revealed peculiarities of not only reaction of blood vessels, but also metabolic reactions to cooling in hypertensive rats [6].…”