摘要:

Groups of Wistar albino rats of both sexes received either gavage with low or high doses of water, ethanol in water, or no treatment. Ninety minutes later they were decapitated and exsanguinated, and samples of brain, ventricular myocardium, renal cortex, liver, skeletal muscle, whole blood, and plasma were obtained. These were analyzed for water, chloride, sodium, and potassium. Corrections were made for residual blood in the heart, kidney, and liver samples. On the basis of an assumed extracellular location of chloride, the intracellular content of water and the concentrations of sodium and potassium in the intracellular water (i.e., chloride-free space) were calculated.All treatments produced a fall in the water content of the blood and a rise in potassium, which were taken as evidence of hemoconcentration. The plasma showed a fall in sodium, which was most marked following the high dose of water and was interpreted as a dilution effect; and a fall in potassium after ethanol, which is not yet explained. Most tissues tended to show a rise in calculated intracellular water and sodium and a fall in intracellular potassium after ethanol, especially after the high dose (4 g/kg). These changes, although statistically significant only in liver and kidney, are compatible with data reported elsewhere which show that ethanol inhibits the active transport of cations across cell membranes.

ISSN:0008-4212    

DOI:10.1139/y66-001

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

Heart–lung preparations (h.l.p.) were made in normal rats, hypophysectomized rats, and in hypophysectomized rats treated with either growth hormone or thyroxine or both. While mean arterial pressure was kept constant at 100 mm Hg, the flow into the heart was increased stepwise until cardiac output did not rise any further (maximum cardiac output (m.c.o.)). Hypophysectomy substantially decreased the m.c.o., even when expressed per kilogram body weight. Thyroxine treatment alone or with growth hormone completely restored the m.c.o. to normal. However, when the m.c.o. was calculated per gram of left ventricle weight, it did not reach the normal level in any of the hypophysectomized rats investigated. Growth hormone, on the other hand, raised the stroke volume (expressed per gram of left ventricle) of hypophysectomized rats without affecting the rate of the heart.

ISSN:0008-4212    

DOI:10.1139/y66-002

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

Heart-lung preparations (h.l.p.) were made in normal rats and in rats with cardiac hypertrophy produced by aortic constriction, thyroxine treatment, or chronic anemia. In the h.l.p., arterial pressure was kept constant at 100 mm Hg, and maximum cardiac output (m.c.o.) was measured by stepwise increase in the inflow of blood until no further rise in cardiac output occurred. The m.c.o. of enlarged hearts was above normal, but not if it was expressed per gram of left ventricle weight. This latter value was not above normal in any of the enlarged hearts, contrary to earlier findings in whole animals. In fact, in one group of severely anemic rats it was significantly below normal.

ISSN:0008-4212    

DOI:10.1139/y66-003

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

An essential preliminary to therapeutic trial of isoproterenol in the treatment of shock was to ascertain whether prolonged infusion of this drug could of itself cause reduction in plasma volume or increase in blood lactic acid levels. In six dogs the levels of plasma volume and of blood lactate and pyruvate were determined at three dosages, 0.067, 0.13, and 0.33 μg/kg per minute, each maintained for 2 hours, before and after splenectomy. There was a small decrease in plasma volume (average, 4.0%) which was not related to the dosage level. The smalt increases in lactate and pyruvate levels (average, 11.4 and 0.4 mg/100 ml, respectively) were also unrelated to dosage. Excess lactate resulting from infusion (average, 6.0 mg/100 ml) did not differ significantly from zero. It was concluded that these changes were of insufficient magnitude to contraindicate the further trial of isoproterenol in the treatment of shock.

ISSN:0008-4212    

DOI:10.1139/y66-004

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

Spreading cortical depression (s.c.d.), elicited by the direct application of potassium chloride to the dura of the rat brain, has been reported to disturb motor functions and learning. In most previous studies these two effects have been confounded. A conditioned response (c.r.) in heart rate was employed in the present investigation in an attempt to separate the effects of s.c.d. on neural integrative and associative processes from the effects on motor performance.The typical cardiac c.r. was acceleration of heart rate (h.r.) during the conditioning stimulus (c.s.) followed by a secondary acceleration after the c.s. terminated. Spreading cortical depression did not alter the initial cardiac acceleration observed during the c.s. although somatomotor (shuttle box avoidance) c.r.'s were almost completely eliminated by it. The second component of the cardiac c.r., h.r. acceleration after the c.s. had terminated, was not observed during s.c.d. Apparently this second component is more easily affected by s.c.d. because it is not under direct sensory control and is therefore dependent upon memory processes. It is concluded that s.c.d. produces a decrement in spontaneous or operant behavior but has little or no influence on environmentally triggered or involuntary behavior.

ISSN:0008-4212    

DOI:10.1139/y66-005

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

In normal Chinese hamsters (Cricetulus griseus) the mean concentration of free fatty acids (FFA) in serum varied from group to group, but was (i) consistently 4 to 9 times greater than in rats, dogs, or man; (ii) slightly higher than in Syrian hamsters; (iii) two- to four-fold higher than in fasting or alloxan-diabetic rats. The epididymal adipose tissue of the Chinese hamster (i) had initial concentrations of FFA comparable to those in the rat and Syrian hamster; (ii) released, in the same time interval, 8- to 10-fold more FFA in vitro than this tissue of the rat; (iii) had higher concentrations of FFA after incubation than the incubated tissue of the rat. The retroperitoneal (perirenal) adipose tissue of the Chinese hamster was less active in release of fatty acids in vitro than the epididymal, but was, however, more active than the epididymal adipose tissue of the rat. These characteristics of FFA metabolism in the Chinese hamster were apparently attributable to species, not to age, diet, or sex. In the Chinese hamster, the weight of the epididymal adipose tissue per gram of body was relatively high. It appears that in this species the rate of release of fatty acids from adipose tissue is great, leading to high FFA concentrations in serum.In Chinese hamster and rat adipose tissues in vitro, glucose and insulin (separately) reduced the rate of release of FFA and the amount of FFA in the tissues, but glucose and insulin together produced the greatest reductions. The net reduction in FFA release by glucose and insulin in vitro was greater in tissue from the Chinese hamster. Insulin markedly increased glucose uptake by the adipose tissues of both species. The possible relation of the results to spontaneous diabetes in the Chinese hamster is discussed.

ISSN:0008-4212    

DOI:10.1139/y66-006

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

Previous reports have shown that dogs treated with the insecticide endrin develop marked changes in blood pressure and heart rate accompanied by convulsions terminating in death. The present study was designed to determine the relationship between venous return (cardiac output), total peripheral vascular resistance, and hypertension seen in succinylcholine-treated dogs after a lethal dose of endrin. Experiments were performed on "intact" (viscera intact) and eviscerated dogs under conditions of total body perfusion. Results indicate that the rise in systemic arterial blood pressure depends primarily on increased cardiac output due to an elevated venous return. Total peripheral resistance does not change significantly in either group of animals. The abdominal viscera were the primary source of the increase in venous return after endrin. Adrenal glands were partially depleted of adrenaline, and increased levels of adrenaline and noradrenaline found in blood plasma may explain the marked alterations in systemic hemodynamics.

ISSN:0008-4212    

DOI:10.1139/y66-007

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

Bovine brain extracts have been fractionated into 89 different subfractions, and the serotonin-like and acetylcholine-like properties of each determined. Thirty-three of the subfractions exhibited biological activity: 6 possessed acetylcholine-like activity; 5 possessed serotonin-like activity; 12 possessed activity of an unknown type; and the remaining 10 possessed more than one type of activity. Eighty of the subfractions contained peptides as revealed by acid hydrolysis. However, it was not established whether the peptides accounted for the biological activities noted.

ISSN:0008-4212    

DOI:10.1139/y66-008

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

The effect of X-irradiation on the cell size distribution of thymus lymphocytes was studied with the aid of an electronic Coulter cell counter.In the thymus the small lymphocytes were the most radioresistant and the large lymphocytes were repopulated before the medium-sized lymphocytes. As the radiation dose was increased from 50 to 400 r, there was a decrease in the large to small thymocyte ratio, and a longer time period was required for a return to the normal ratio. Single and repeated doses of X-irradiation produced much the same type of effect on the large to small ratio of both thymus and spleen lymphocytes, and it was concluded that the effects of X-irradiation on the cell size distribution of lymphocytes in the thymus and spleen were similar.

ISSN:0008-4212    

DOI:10.1139/y66-009

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

Xenon133was used to measure distribution of ventilation and perfusion in the upper, middle, and lower lung zones of 12 upright healthy male subjects, at rest and during exercise, while breathing room air and after breathing 100% oxygen for 20 minutes. During the breathing of both air and 100% oxygen, ventilation and perfusion increased from the apex to the base of the lung, the differences between upper and lower zones becoming less pronounced during exercise. Oxygen breathing did not appear to affect distribution of regional ventilation or perfusion in normal upright man, either at rest or during exercise. This negative result is of importance in relation to the possible role in intact man of homeostatic mechanisms of adjusting perfusion and ventilation, which are sensitive to oxygen tension.

ISSN:0008-4212    

DOI:10.1139/y66-010

出版商:NRC Research Press    

年代:1966

数据来源: NRC