Showing papers in "Journal of Clinical Investigation in 1961"

Leukokinetic studies. iv. the total blood, circulating and marginal granulocyte pools and the granulocyte turnover rate in normal subjects

Abstract: When granulocytes are labeled with diisopropyl-fluorophosphate (DFP32) and then returned to the circulation of the donor, the labeled granulocytes are distributed in a pool of cells which is approximately two times larger than that calculated from the blood volume and the concentration of granu-locytes in the circulating venous blood (1, 2). This pool has been referred to as the total blood granulocyte pool (TBGP) and it consists of two subcompartments or pools. These pools have been designated the circulating granulocyte pool (CGP) and the marginal granulocyte pool (MGP). The size of the CGP can be calculated from the blood volume and the absolute granulocyte count. Equilibration between the granulocytes in the CGP and in the \"noncirculating\" or MGP is sufficiently rapid and complete to allow these two pools to be considered as one kinetically, and the size of the TBGP can be determined by the isotope dilution principle. Since the cells are removed from the TBGP in an exponential fashion with a mean half-time disappearance (Ti) of 6.6 hours, the granulocyte turnover rate (GTR), that is, the number of granulocytes turned over through the blood in a unit of time, can be calculated. The purpose of this paper is to present data on the GTR in normal subjects, as well as additional data on the size of the TBGP, CGP and MGP in normal subjects. The influence of steroids, physical exercise, epinephrine and bacterial endotoxin on these parameters in normal subjects has also been studied. Twenty-five volunteers from the Utah State Prison, in addition to the 45 subjects previously reported (1, 2), were used in these studies. All of the subjects were normal healthy males, 20 to 50 years of age, with normal leukocyte values. The subjects ate breakfast at 6:00 a.m. and the infusion of labeled blood was begun between 8:00 and 10:00 a.m. The methods for labeling blood in vitro, for the isolation of leukocytes from the blood samples, for the determination of leukocyte radioactivity, and for the calculation of the TBGP, CGP and T± have been described in previous publications (1, 2, 5). The GTR, defined as the number of granulocytes turned over through the blood each day per kilogram body weight, was calculated from the following equation (6): GTR = 24 X 0.693/Ti (hrs) X TBGP (no. cells X 107/kg). The DFP32 was purchased from the New England Nuclear Corp., Boston, Mass., as a dilute solution …

The effect of ethanol on fatty acid metabolism; stimulation of hepatic fatty acid synthesis in vitro*

Abstract: Seventy-one male Sprague-Dawley rats weighing from 250 to 400 g were maintained on Purina Laboratory Chow, except for a 24 hour period immediately preceding the experiment. During this period, they were given 36.5 g glucose per kg together with 7.5 g ethanol per kg or, in the experiment shown in Table III, 50 g per kg fructose, administered by means of 5 gastric tube feedings of equal volume. Approximately 3 hours after the last gastric feeding, the animals were decapitated. The liver was quickly removed, and slices were prepared in the cold with a Stadie-Riggs slicer (4). The C14-labeled 1 and unlabeled substrates were dissolved in 5 ml isotonic KrebsRinger bicarbonate buffer, pH 7.4 (6), and the final concentration of the substrates was expressed as millimoles per liter. An aliquot of each incubation mixture was added to a toluene solution containing 12 per cent methanol, 0.4 per cent diphenyloxazole (DPO) and 0.005 per

Ion association. vi. interactions between calcium, magnesium, inorganic phosphate, citrate and protein in normal human plasma*

Abstract: The total measured concentration of an ionizable constituent of body fluids often fails to reveal either the varied chemical forms in which it may be present, or the portion which is present as the free ionized substance. This truism applies to most organic acids and bases and to inorganic ions which are multivalent. Univalent ions whose cor

Stimulation of active sodium transport by the isolated toad bladder with aldosterone in vitro

Abstract: The tubular reabsorption of sodium in the mammalian kidney is stimulated after administration of aldosterone (1-3). The transport of sodium from the tubular lumen to the interstitial compartments, across the cells lining the renal tubule, represents an active process (4, 5), and one is therefore led to conclude that this process is influenced by aldosterone. However, the failure to observe a sodium retention confined to the treated side after injection of aldosterone into one renal artery of the normal dog (3) could cast doubt that aldosterone is the principle immediately responsible for renal sodium retention. The time lag of 1 to 2 hours regularly observed between intravenous administration of aldosterone and the first changes in sodium excretion by the kidney (6-8) is likewise intriguing. The isolated toad bladder was thought suitable for a more direct examination of the stimulation of sodium reabsorption by aldosterone. This preparation consists of a single layer of mucosal cells supported by thin connective tissue in which blood vessels and isolated bundles of smooth muscle are interspersed; a layer of serosal cells separates the bladder from the peritoneal cavity. This simple biological membrane is capable of moving sodium actively from its mucosal to its serosal border (9), a process that can be conveniently followed by the short-circuit technique of Ussing and Zerahn (10). These investigators have shown that, when an external potential is applied so as to

Uric acid production in gout

Abstract: If-primary gout is an \"inborn error of metabolism,\" as has been postulated (1), all patients might be expected to share a common, underlying defect to account for their hyperuricemia. Disagreement has centered about the problem of whether the primary derangement involves an impairment of urate disposition or an acceleration of urate biosynthesis. In the past a variety of methods has been employed to' assess urate biosynthesis and disposition in -gouty patients. The 'daily excretion of uric acid in the urine is a convenient parameter to measure but does not include that portion of urate production which is destroyed by uricolysis or is deposited in tophi in gouty patients. Benedict, Forsham and Stetten (2) and Bishop, Garner and Talbott (3) used uric acid-N15 to estimate the magnitude of the body urate pool and its rate of turnover. Benedict and co-workers observed that, in those gouty patients with extensive tophi and greatly 'expanded urate pools, such data may not provide a valid measure of urate synthesis, since uric acid from tophaceous deposits may dilute the administered isotopically labeled urate in a manner indistinguishable from that of newly synthesized uric acid. Urate biosynthesis has also been studied by measuring the extent of incorporation of an isotopically labeled precursor into urinary uric acid. Some, though not all, of the gouty subjects studied were found to incorporate excessive amounts of glycine-N'5 into urinary uric acid (4, 5). When trace amounts of glycine-1-C14 were used in similar studies, an excessive incorporation of isotope into urinary uric acid was found in all of the six gouty subjects first investigated (6), but subsequent studies showed that there were some gouty patients in whom excessive incorporation of glycine-1-C4 into uric acid could not be detected (7-9). An excessive production of uric acid could exist in such gouty patients, yet fail to be reflected in the extent of glycine incorporation into urinary uric acid because of enhanced extrarenal disposal of urate through deposition in tophi or increased uricolysis The purpose of the present investigation was to evaluate urate production in gouty subjects in a manner that would allow corrections to be made for the extra-renal disposal of urate. Studies were performed with isotopically labeled glycine to evaluate purine synthesis and isotopically labeled uric acid to evaluate the dynamics of the urate pool. The determination of the urate pool turnover provided an independent estimate of uric acid biosynthesis. The results obtained wer'e correlated with clinical features of the disease and with urinary excretion of uric acid. On the basis of these studies, some conclusions were drawn regarding the relative roles of excessive urate production and impaired urate disposition in the pathogenesis of the hyperuricemia of gout.

Studies on the pathogenesis of the ethanol-induced fatty liver. I. Synthesis and oxidation of fatty acids by the liver.

Abstract: In studying the effects of ethanol on the liver, we have directed our attention to the manner by which ethanol intoxication in animals causes an acute fatty liver (1, 2). Although the mechanism involved is still not well understood, the production of the fatty liver under these conditions probably involves one or more of the following four processes: 1) increased hepatic lipid synthesis, 2) decreased hepatic lipid utilization (e.g., oxidation), 3) increased transport of fatty acids from peripheral fat depots or 4) decreased release of lipid from the liver. Mallov and Bloch (1) originally suggested that the fatty liver following ethanol administration was due to an increased transport of fat from the depots to the liver, but later (3) considered that the increased hepatic lipid might be the result of increased hepatic fatty acid synthesis. Consistent with the latter concept are the observations of Lieber, DeCarli and Schmid (4, 5) that ethanol, in vivo and in vitro, stimulates fatty acid synthesis in the liver. These authors attributed the enhanced fatty acid synthesis to an increased production of reduced diphosphopyridine nucleotide (DPNH) produced by the oxidation of ethanol (5). On the other hand, good evidence has been presented recently (6, 7) that increased transport of fatty acids to the liver from the fat depots may be the major mechanism for the fatty liver produced by ethanol as well as by other agents, such as ethionine and carbon tetrachloride. To gain further insight into the mechanism whereby ethanol intoxication produces a fatty liver, we have investigated the four processes referred to above in order to determine the extent to which one or more of them may be involved.

The relationship of oxygen cost of breathing to respiratory mechanical work and respiratory force

Abstract: The oxygen cost of increased respiratory activity can be measured by subtracting the oxygen consumption at rest from that observed during the increased respiratory activity. The efficiency of the system can be assessed when the increased respiratory mechanical work is related to the oxygen cost. Previous estimates of efficiency in man have varied very widely, possibly because very different forms of respiratory work have been employed. Some workers have increased the pressure component of respiratory work by additions to the external air flow resistance, a procedure which will be referred to hereafter as \"resistance breathing.\" In other studies, the volume component of respiratory work has been augmented by increasing the minute volume, without any addition of airway resistance: this will be referred to as \"hyperventilation.\" No investigator employing one experimental technique has studied the oxygen cost of both of these forms of activity. The first objective of this study was to ascertain whether the relationship of oxygen cost to mechanical respiratory work is the same for hyperventilation as for resistance breathing in normal subjects. The second was to test whether the same relationships hold in the presence of diseases which alter the mechanical properties of the lung. There is evidence, however, that mechanical work is not the most revealing parameter with which to compare energy consumption. For example, the support of a heavy object at a fixed distance from the ground involves energy consumption but results in no measurable mechanical work, although it is likely that the increased energy consumption would relate to the weight of the object and the length of time it was supported.

The role of plasma free fatty acids in development of fatty liver.

Abstract: The accumulation of fat in the liver under many diverse experimental conditions has frequently been used as an index of fat mobilization from adipose tissue (1-6). In recent years, it has become clear that the free fatty acids (FFA) of the plasma represent a major transport form for mobilization of lipid from adipose tissue (7, 8) and methods are now generally available for measurement of this important plasma lipid component (7, 9, 10). Therefore, it is now possible to examine more directlv this inferred relationship between mobilization of fat and the development of fatty liver. The present experiments were designed to determine whether increasing the rate of mobilization of fatty acids from the periphery in normal animals might lead to development of fatty liver. Epinephrine causes an immediate and marked increase in the rate of release of FFA from adipose tissue in vitro (11) and in vivo (12), and norepinephrine acts similarly (13, 14). Because the FFA response to norepinephrine is smoother and more sustained than the response to epinephrine (13), the former has been used in most of these experiments.

The disappearance of 7-H-3-d-aldosterone in the plasma of normal subjects.

Abstract: The study of the disappearance of the radioactivity in plasma after the injection of labeled aldosterone should elucidate the transport and metabolism of this steroid in man. In particular this would allow the calculation of the turnover rate in various clinical conditions. This value, together with a concomitant determination of the secretion rate estimated from the specific activity of a urinary metabolite, would enable the mean blood concentration of aldosterone to be calculated. This is particularly important at the present time, as no practical direct method has yet been reported for the analysis of aldosterone in peripheral blood. After the administration of 16-H13-aldosterone to one normal subject, the labeled hormone had a half-life in plasma of 20 minutes, as calculated from the change in concentration of radioactivity measured specifically as aldosterone between 2 and 3 hours after the injection (1). This indicated that the rate of metabolism of aldosterone was greater than that of cortisol and corticosterone. The data obtained were not sufficient to give a relialle estimate of volumes of distribution. Also, the low specific activity of aldosterone then available made it necessary to administer 2 jug of hormone. This amount represents about 25 per cent of total body pool of hormone. Peterson reported a corresponding half-life of 0.5 to 0.8 hour in normal subjects after injection of tritiated d,l-aldosterone (2). Again in this study large quantities of the hormone were injected. Also it is not known whether the optical isomers of aldosterone are metabolized in an identical manner. The natural hormone is in the d form exclusively.