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A study of the cardiovascular changes induced by stimulation of the motor cortex in dogs
Fedorov, perature tions.
N. A., and Shur, 24, I.: of the Body Am. *J. Physiol.
The Role of the Viscera
of an Animal 137: 30, 1942.
Under
Physiologic
in Regulating and Pathologic
the
TemCondi-
Thermogenesis in the viscera (liver and intestines’) was stullied in n~~rrnul, artificially cooled and heated animals, as IveIl as during fel~ril~~ stat<9 ~:tused I)? homogeneous and heterogeneous l~lood transfusions. The experiments were made on angiostomized dogs with cannulas in the portal and hepatic veins; in each animal the rectal temperature and the temperature of the blood in the abdominal aorta and the portal and hepatic veins were measure(l. The thermoelectric method used throughout the experiments detected changes in temperature with suficient accuracy an<1 matle it possible to study thermotopography in the organism. In normal fasting dogs the luwest temperature of the ljlood was fouu~l in tilt, aorta and the highest in the hepatic vein. The experiments have shown important thermogenesis in the intestines. When the animals were cooled by the application of ice to the skin, the difference in temperature between the blood in the hepatic and the portal veins iI)creased, i.e., there was a rise in hepatic heat production (three to six times the original level), providing the blood flow was accelerated; when the animal was overheated, the reverse took place. Homogeneous blood transfusion did not, bring about not&able changes in thermsgenesis in the liver and the intestines, despite a systentic rise in temperature. The febrile state caused 1)~ heterogeneous transfusiou is accompanied 1)~ a noticeable increase in thermogenesis in t,he liver and intestines. A comparative study of the hemodynamic variations has shown that the increase in hepatic and intestinal thermogenesis cannot be explained by the influence of circulatory factors. After ansphylactic shock, the same changes were observed as in tile case ot’ heterogeneous transfusion, but the variations in temperature were much greater+ especially with respect to the intestines. The increase in visceral thermogenesis proceeds parallel to the systemic tem perature reaction, i.e., the liver and the intestines participate iu determining the febrile process accompanying the transfusion of foreign 11lootl. The use of the ntethod of E. I. London for studying visceral thermogencsis iu angiostomized dogs considerably widens the sphere of its apl~liration and promises to give results of great practical and theoretic interest. ~~l”rHoRs.
J&u, S-H, Iiwang, K., and Chu, H-N.: A Study of the Cardiovascular Changes Induced by Stimulation of the Motor Cortex in Dogs. -km. J. Physiol. 137: 468, 1942. By stimulation of the motor focal points ou the sigmoid gyrus of the dog anesthetized with chloralose, there is always a fall of blood pressure. The depress01 effect thus produced is always associated with the muscular mo%-ement in IIOIIcurarized animals, but the production of the former is not dependent on the latter. The intensity of the depressor effect evoked from the cortical stimulation in dogs is determined by the strength of the stimulating current and by the particular motor focal point that is stimulated. 20 per cent ou stimulatiou of the The heart rate is usually imreased about motor area in dogs, but the change of the heart rate is not a casual factor in the depressor effect, since the latter is not influenced or abolished by section of l)oth vagi. The respiratory movements are usuallydecreased in amplitude and inc.reased in number, and occasionally apnea may occur during cortical stimulation. The renal volume is always increased accompanying the fall of blood pressure Vasodilation of the visceral organs is probably following cortical stimulation. the cause of the depressor effect. AUTHORS.
N. A., and Shur, 24, I.: of the Body Am. *J. Physiol.
The Role of the Viscera
of an Animal 137: 30, 1942.
Under
Physiologic
in Regulating and Pathologic
the
TemCondi-
Thermogenesis in the viscera (liver and intestines’) was stullied in n~~rrnul, artificially cooled and heated animals, as IveIl as during fel~ril~~ stat<9 ~:tused I)? homogeneous and heterogeneous l~lood transfusions. The experiments were made on angiostomized dogs with cannulas in the portal and hepatic veins; in each animal the rectal temperature and the temperature of the blood in the abdominal aorta and the portal and hepatic veins were measure(l. The thermoelectric method used throughout the experiments detected changes in temperature with suficient accuracy an<1 matle it possible to study thermotopography in the organism. In normal fasting dogs the luwest temperature of the ljlood was fouu~l in tilt, aorta and the highest in the hepatic vein. The experiments have shown important thermogenesis in the intestines. When the animals were cooled by the application of ice to the skin, the difference in temperature between the blood in the hepatic and the portal veins iI)creased, i.e., there was a rise in hepatic heat production (three to six times the original level), providing the blood flow was accelerated; when the animal was overheated, the reverse took place. Homogeneous blood transfusion did not, bring about not&able changes in thermsgenesis in the liver and the intestines, despite a systentic rise in temperature. The febrile state caused 1)~ heterogeneous transfusiou is accompanied 1)~ a noticeable increase in thermogenesis in t,he liver and intestines. A comparative study of the hemodynamic variations has shown that the increase in hepatic and intestinal thermogenesis cannot be explained by the influence of circulatory factors. After ansphylactic shock, the same changes were observed as in tile case ot’ heterogeneous transfusion, but the variations in temperature were much greater+ especially with respect to the intestines. The increase in visceral thermogenesis proceeds parallel to the systemic tem perature reaction, i.e., the liver and the intestines participate iu determining the febrile process accompanying the transfusion of foreign 11lootl. The use of the ntethod of E. I. London for studying visceral thermogencsis iu angiostomized dogs considerably widens the sphere of its apl~liration and promises to give results of great practical and theoretic interest. ~~l”rHoRs.
J&u, S-H, Iiwang, K., and Chu, H-N.: A Study of the Cardiovascular Changes Induced by Stimulation of the Motor Cortex in Dogs. -km. J. Physiol. 137: 468, 1942. By stimulation of the motor focal points ou the sigmoid gyrus of the dog anesthetized with chloralose, there is always a fall of blood pressure. The depress01 effect thus produced is always associated with the muscular mo%-ement in IIOIIcurarized animals, but the production of the former is not dependent on the latter. The intensity of the depressor effect evoked from the cortical stimulation in dogs is determined by the strength of the stimulating current and by the particular motor focal point that is stimulated. 20 per cent ou stimulatiou of the The heart rate is usually imreased about motor area in dogs, but the change of the heart rate is not a casual factor in the depressor effect, since the latter is not influenced or abolished by section of l)oth vagi. The respiratory movements are usuallydecreased in amplitude and inc.reased in number, and occasionally apnea may occur during cortical stimulation. The renal volume is always increased accompanying the fall of blood pressure Vasodilation of the visceral organs is probably following cortical stimulation. the cause of the depressor effect. AUTHORS.