Henry D. Lauson

Metabolism of antidiuretic hormones

T HE RATE of change in the plasma concentration of antidiuretic hormone (ADH) is determined as much by the rate of removal of the hormone from the blood as it is by the rate of secretion into the blood [I]. It is evident, however, that in the control of osmolal concentration of the body fluids it is the secretory process that is the regulated variable. The removal process operates in a blind, continuous manner, clearing ADH from a more or less constant fraction of the plasma volume each minute, whether the plasma concentration is high or near zero. In this view, change in clearance modifies only the time required for correction of a disturbance in plasma osmolal concentration but does not affect the value at which osmolal concentration stabilizes [Z]. It is also evident that the removal process in the responsible organs must be subject to controls, but only a beginning has been made toward understanding the metabolic factors involved. Even the effect of change in as obvious a factor as blood flow through such an organ has been examined in only a few studies.

Recording of Right Heart Pressures in Man.

Utilizing the right heart catheterization technic of Cournand and Ranges, 1 the cyclic pressure changes in the right auricle and right ventricle have been recorded with the Hamilton manometer 2 in 50 individuals. Catheterization of the right auricle was performed as previously described. 1 , 3 The patients experienced little or no discomfort during the procedure. The level of the catheter in the heart by lateral X-ray was taken as zero pressure. Introduction of the catheter with a slightly curved tip into the right ventricle under fluoroscopic control was not difficult as a rule, and was signaled first by a rise above auricular pressure, then by large oscillations at cardiac rate in the saline monometer connected to the catheter. Addition of the long narrow catheter (No. 8 or 9) to the manometer system decreases the natural frequency. Frequencies obtained with this system have varied from about 25 to 50 vibrations per Second. Although not ideal, this range has proved fairly adequate except in the presence of tachycardia or very vigorous cardiac contractions. Oscillatory phenomena were common, especially in low pressure ventricular complexes, but at present it is not certain whether some of these are artifacts dependent upon the presence of the catheter (see Fig. 1A and 2). The general contours of the pulse waves are believed to be reasonably accurate. Results. In 8 normal subjects the right ventricular pressure averaed 22 mm mercury at the height of systole (range 18-28) and about zero during most of diastole. There was a cyclic variation of about one to 3 mm mercury due to quiet respiration (Fig. 1A). The systolic contour was full, resembling curves obtained in dogs by Wiggers. 4 In the few cases of mild and moderate essential hypertension, the pressures were not outside the normal range.

RENAL WATER EXCRETION IN PREMATURE INFANTS

It is generally believed that, after water ingestion, the young infant can neither dilute his urine nor increase the rate of urine flow as rapidly or as effectively as the adult (1-4). Although several sound investigations (4-6) have demonstrated that the kidneys of newborn animals are relatively inefficient in this regard, there have been very few direct observations on these important functions in infants. The present investigation was undertaken, therefore, to compare the renal response of the young premature infant with that of the older infant and adult to ingestion of water.

The effect of corticotropin (ACTH) on glomerular permeability to albumin in children with the nephrotic syndrome.

Present evidence indicates that proteinuria in patients with the nephrotic syndrome is the result of increased permeability of the glomerular capillary walls to proteins, particularly to albumin (1, 2). A rough indication of the permeability to albumin, relative to permeability to water, is provided by the ratio of the concentration of albumin in glomerular fluid to that in plasma. Assuming that no albumin is excreted by the tubules, the rate of albumin excretion (in mg. per min.) divided by the rate of glomerular filtration of water (GFR, in ml. per min.) represents the lowest possible concentration of albumin in glomerular fluid (in mg. per ml.) ; if some albumin is reabsorbed by the tubules, as seems likely, the actual concentration of albumin in glomerular fluid would be greater than this calculated value. If it is accepted that the clearance of inulin (CIN) is equivalent to GFRin children with the nephrotic syndrome (3), it follows that the renal clearance of albumin (CALB) divided by CIN, i.e., CALB/CIN, represents the minimum ratio of the albumin concentration in glomerular fluid to that in plasma. Chinard, Lauson, and Eder (4) showed that in patients with the nephrotic syndrome the renal clearance of the blue dye, T-1824 (CT_1824), was somewhat less than but approximately proportional to CALB. It would appear, therefore, that where large changes in permeability are expected CT_1824 should be a satisfactory substitute for CALB. The

Double Lumen Catheter for Intravenous and Intracardiac Blood Sampling and Pressure Recording.

Summary 1. Simultaneous blood samplings and pressure recordings in 2 continuous segments of the circulatory system may be obtained in man by means of a specially designed double-lumen catheter. 2. The difference in oxygen content of 2 blood samples withdrawn simultaneously from 2 points located 10 cm apart in the right auricle and right ventricle was well within the limits of technical error in 8 out of 9 cases. 3. Examples are given of the recording of simultaneous mechanical events in (a) the right auricle and ventricle, (b) the right ventricle and the pulmonary artery.

CHEMICAL, CLINICAL, AND IMMUNOLOGICAL STUDIES ON THE PRODUCTS OF HUMAN PLASMA FRACTIONATION. VIII. CLINICAL USE OF CONCENTRATED HUMAN SERUM ALBUMIN IN SHOCK, AND COMPARISON WITH WHOLE BLOOD AND WITH RAPID SALINE INFUSION

The present report is concerned primarily with the use of concentrated human albumin solutions, produced from pooled normal human plasma by the method of Cohn and co-workers, (1), in the treatment of shock in man.This work represents a part of a more general study (3) of the circulation in human cases of shock, which has been in progress at Bellevue Hospital, New York City, during the past two years. In addition, the -therapeutic effects of concentrated human albumin will be compared with the effects of whole blood, and of rapid intravenous saline infusion. Before presenting the results of this investigation, it may be well to define briefly two separate aspects of shock therapy, since the differentiation of these provides the basis of our comparison of the three types of treatment used. For successful treatment of clinical shock, two things are essential; first, to restore the failing