Abraham Dury

Lipides Distribution and Phospholipide Turnover in Tissues of Rabbit Shortly After Growth Hormone

Summary 1. A study was made of the effects of a single injection of anterior pituitary purified growth hormone on distribution of lipides and turnover of phospholipides in plasma, liver and aorta a few hours after administration in intact rabbits. 2. Plasma glucose and liver glycogen concentration, and total liver weight were moderately, but significantly, increased in animals which received growth hormone. 3. Contents of all lipide fractions of plasma and entire liver were significantly increased in experimental animals. In the aorta, the only change was a significantly decreased neutral fat content. 4. Liver total lipide content was increased 64%, plasma total lipide was increased 85%, and aorta total lipide was decreased 25%. The relative contribution of each lipide fraction to percentage increased or decreased total lipide determined in these tissues was as follows: in liver, neutral fat contributed 47%, phospholipide 15%, and free and ester cholesterol 1.5% each; in plasma, neutral fat contributed 53%, phospholipide 19%, free cholesterol 6%, and esterified cholesterol 8%; in the aorta, neutral fat contributed 100%. 5. Radioactivity data showed that accelerated synthesis of liver and plasma phospholipides occurred after treatment with growth hormone; but aortic phospholipide turnover was not different from controls. 6. It is suggested that increased rate of formation of phospholipides of liver and plasma need not necessarily be a specific effect of growth hormone but a change in this parameter of metabolism subsidiary to enhanced mobilization of endogenous fat. It is further suggested that all elements of altered distribution of lipides in tissues analyzed could be explained in accordance with the concept of a primary adipo-kinetic action of growth hormone.

Occurrence of Premature Ovulation in the Domestic Fowl Following Administration of Progesterone.

Summary The administration of crystal-line progesterone to the common domestic hen is highly effective, under stated conditions, in causing premature ovulation of normally developing ovarian follicles. Results differ with route of injection, time from injection to expected normal ovulation, injection level, and place of the follicle in the clutch sequence. First follicles of clutch sequences are ovulable at least 6 hours prematurely in 90 to 95% of hens receiving 0.5 and 1.0 mg progesterone intravenously, or 1.0 to 10.0 mg subcutaneously. Follicles other than the first of clutch sequences are ovulable by at least 7 hours prematurity in 70 to 75% of subcutaneously injected hens at dosage levels of 0.5 to 5.0 mg progesterone. Under identical conditions the intravenous administration of progesterone is relatively ineffective. Observed intervals from injection to ovulation varied from 7 to 11 hours.

THE CHANGES IN PLASMA POTASSIUM LEVEL AFTER EPINEPHRINE IN NORMAL HUMAN BEINGS AND IN PERSONS WITH EPILEPSY

Biochemical studies directed toward finding a difference in the blood composition of normal and epileptic subjects have thus far been unfruitful. In the course of other studies at this laboratory (1), it was observed that the pattern of change in the plasma potassium level after an injection of epinephrine in a subject afflicted with epilepsy was different from that found in normal subjects similarly treated. An investigation was therefore undertaken to measure the changes in the concentration of plasma potassium, sodium and glucose at several time-intervals after an injection of epinephrine in epileptic patients and in normal human subjects. The results of this investigation showed that there was a significant difference in the pattern and extent of change in the plasma potassium level of epileptic subjects compared to normals subsequent to administration of epinephrine. There was no difference in the plasma sodium levels and only a probably significant difference in the extent of change in the plasma glucose level.

Immediate Effects of Epinephrine on Phospholipides Turnover and Lipide Partition in Plasma, Liver and Aorta

Summary 1. The lipides partition and phospholipides turnover in plasma, liver, and aorta of intact rabbits was determined 6 hours after the subcutaneous injection of 1 mg/kg epinephrine in oil. 2. Significant changes were found in certain lipide fractions of liver and plasma but no alterations in the concentrations of the various aortic lipide fractions. 3. Specific activities of the plasma, liver and aortic phospholipides were significantly elevated in the rabbits given epinephrine; a particularly large change was found in the rate of aortic phospholipides formation. The possible relationship of the latter finding to the development of arteriosclerosis was discussed.

Changes in Plasma and Tissue Water and Electrolytes After Epinephrine Administration in Rats

Summary Analyses of plasma and tissue water and electrolytes content were made in intact and adrenalectomized groups of rats untreated and 60 minutes after epinephrine injection. Evidence was presented that the plasma potassium concentration was significantly decreased in intact and adrenalectomized rats after epinephrine compared to their respective controls. The potassium content of muscle tissue was significantly decreased in the epinephrine treated intact and adrenalectomized groups. There was no change in the water, sodium or chloride concentration of plasma after epinephrine in either intact or adrenalectomized groups. However, there was a significant decrease in intracellular water content and increase in extracellular water content which was briefly discussed as linked to the change in potassium content. None of these changes were determined in liver tissue of the intact or adrenalectomized groups 60 minutes subsequent to epinephrine injection. In view of the above results and the evidence that the sodium and chloride content of muscle of the intact group was significantly increased after epinephrine but not so in the adrenalectomized group, the results were briefly discussed as evidence of an effect of epinephrine on the potassium “balance” in the compartments of the organism.

Lipid Distribution and Metabolism in Two Areas of Aorta of Normal and Cholesterol-fed Rabbits:

Summary Lipid partition and phospholipid metabolism of the aortic arch and descending limb of aorta, plasma and liver were determined in groups of rabbits on a normal diet and 40 and 70 days on a cholesterol-supplemented diet. In all groups, the descending limb of aorta had significantly lower total lipid, primarily due to decreased neutral fat concentration, compared with the aortic arch. In normal rabbits the specific activity of phospholipid in the descending aorta was significantly greater than that of the aortic arch. However, this distinction in phospholipid synthesis between the two areas of aorta was not found in the groups of rabbits on the high-cholesterol diet. The radioactivity data indicated this was due to an increased rate of formation of phospholipid in the aortic arch of rabbits fed the cholesterol-supplemented diet, particularly those rabbits on the diet for 70 days, and probably was related to the development of atheromatous lesions in the arch only of these rabbits. The results were discussed in relation to the general problem of local factors in the arterial wall influencing the localization and subsequent development of atherosclerotic lesions.

Adrenal weight and ascorbic acid concentration in alloxan-injected rats.

Summary The mean adrenal weight/100 g body weight, and the adrenal ascorbic acid concentration of groups of rats approximately 3 days after subcutaneous or intravenous injection of alloxan were shown to be significantly greater than the respective mean values in intact rats. The extent of adrenal ascorbic acid depletion 60 minutes after subjection to an acutely stressful condition (208 mg glucose solution by intravenous administration) in intact and alloxan-injected groups was practically identical; and significantly lower concentration than control values were obtained. The results were discussed as further evidence of the problem whether adrenal ascorbic acid concentration may be considered a reliable guide of hyper- or hypofunction of the adrenal cortex. A tentative explanation of the increased ascorbic acid concentration in the alloxan-diabetic groups was also discussed.

Effect of epinephrine and insulin on tissue electrolytes in normal and demedullated rats.

Summary 1. The effect of epinephrine and insulin administration on the water and ionic content of plasma, skeletal muscle, and liver was compared in normal sham-operated and adrenal demedullated (21 days after surgery) groups of rats. Histological evidence was presented that the regenerated adrenal cortices appeared normal and medullary tissue was absent. 2. A significant reduction in plasma and muscle potassium concentration was determined 60 minutes after epinephrine administration in the sham and demedullated groups. A decreased plasma potassium level 60 minutes after insulin administration was found in the sham group but not in the demedullated group. However, a significant increase in the plasma sodium concentration after insulin was determined in both sham and demedullated groups. 3. The results were discussed as indicating that the apparent effect of insulin upon the plasma potassium level in the intact animal was the resultant of “reflexly” elicited epinephrine secretion following insulin-induced hypoglycemia and not the effect of insulin per se.

Changes in Lipid and Electrolyte Concentrations in Adrenalectomized Rats After Alloxan

Summary 1. Concentrations of liver lipid components, and liver, muscle and plasma electrolytes, glycogen and glucose were determined at 4, 24, and 72 hours after alloxan injection in adrenalectomized groups of rats. One series was maintained with 1% NaCl and a second series received daily injections of small levels of Lipo-adrenal extract in addition to the saline. In both series a moderate hyperglycemia was extant at 72 hours after alloxan; but at 4 and 24 hours the blood glucose levels were only slightly or not different from the controls. This was in marked contrast to the hyperglycemia found in intact rats at these intervals after alloxan. 2. In contrast to the changes in concentration in liver lipid components and liver and plasma electrolytes found in intact rats after alloxan at these periods, adrenalectomy apparently effectively prevented their occurrence. 3. An increase in the exogenously administered dose of adrenocortical material just before alloxan injection resulted in significant alterations in liver lipid components as well as increased potassium concentration in plasma, muscle, and liver.

Epinephrine and insulin effect on potassium mobilization; relationship of lipid and carbohydrate metabolism.

Summary The effects of epinephrine and of insulin pretreatment on liver lipid partition, glycogen, water and electrolytes content, and certain plasma constituents were compared in adrenalectomized-alloxanized groups of rats given a glucose infusion. A similar pattern of changes in liver lipid partition was found in both pretreated groups compared to the non-pretreated controls. An increased liver potassium and lowered plasma potassium content was found in both pretreated groups. However, differences in liver glycogen content and glycemic level in the pretreated groups were sufficiently notable to suggest that common resultant effects on potassium mobilization probably were not produced by the same mechanism of action of both hormones.