Effect of Tourniquet Shock and Acute Hemorrhage on the Circulation of Various Organs in the Rat

Abstract

Cardiac output, blood pressure, and organ fractions of cardiac output, except the brain, were determined in rats subjected to tourniquet shock and to hemorrhage. Bleeding involved the withdrawal of 23 and 32 ml./Kg. blood, respectively, and determinations were carried out 5 to 20 minutes after bleeding. Sapirstein's "indicator fractionation" method with Rb 86 was used for the determination of the cardiac output fractions. Blood flow and circulatory resistance of the organs were calculated from the experimental data. Cardiac output was not measured after severe (32 ml./Kg.) hemorrhage. In tourniquet shock at 50 mm. Hg blood pressure, the cardiac output and the blood flow in all organs decrease while vascular resistance of the skin and of the "carcass" (skeleton, muscles, endocrine organs) increases. The heart, "lung," and the liver fractions of cardiac output increase, renal and skin fractions decrease. After moderate hemorrhage at 47 mm. Hg blood pressure, cardiac output and the blood flow of the organs are low. Vascular resistance of all organs other than the heart and the "lung" rises. Cardiac output fractions of the heart, "lung," and "carcass" increase; renal and cutaneous fractions decrease. In severe hemorrhage, the redistribution of cardiac output has a similar tendency but is usually more pronounced.

Ultrastructure of the Kidney in Tourniquet Shock

“…toxic components liberated from the traumatized tissues have not been proved to be an important cause of shock. Possibly, toxins and procoagu lants are liberated from ischaemic tissues [6,20], More attention has been paid to hypovolaemia produced after the release of the tourniquet [4,17,37]. In the remainder of this article, we compare the ultrastructural changes found in the kidneys in tourniquet shock with those produced by other types of shock and draw conclusions about the pathogenesis of the former.…”

“…The oedema in the limbs decreases the circulating blood volume; cardiac output is de creased by two thirds and renal perfusion by three quarters of normal [37]. A llen [4] showed that injections of physiological saline can resusci tate the animals from tourniquet shock.…”

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“…From the values of cardiac output, blood pressure, organ weights and fractions of cardiac output, organ blood flow and vascular resistance were calculated for 100 g tissue; the total peripheral resistance was also calculated (Sapirstein, 1958;Takacs et al, 1962). Alterations in blood pressure and cardiac output in the range occurring in these experiments did not modify the extraction rate of 'Rb from the blood (Takacs, Kallay & Karai, 1964).…”

“…The method using the fractional distribution of indicators (Sapirstein, 1956(Sapirstein, , 1957(Sapirstein, , 1958 was of value in estimating regional distribution of the cardiac output and has been widely used in our laboratory (Takacs, Kallay & Skolnik, 1962;Takacs & Vajda, 1963;Takacs, 1965). It was shown that pronethalol (10 mg/kg) had only slight circulatory effects in rats while the effects of dichloroisoprenaline (10 mg/kg) were mostly due to its sympathomimetic activity (Debreczeni & Takacs, 1968).…”

Carotid-Sinus Baroreflex Modulation of Core and Skin Temperatures in Rats: An Open-Loop Approach

“…It is also indicated that carotid baroreceptor unloading had no effect on skin blood flow in humans [6]. On the other hand, there is literature demonstrating that hemorrhaging is clearly associated with cutaneous vasoconstriction through sympathetic activation in mice [7], rats [8][9][10][11], rabbits [12,13], and dogs [14]. However, its mechanism for hemorrhage-induced skin vasoconstriction still remains controversial.…”