Although numerous clinical studies have centered about the infusion of epinephrine and norepinephrine (1-3), the plasma concentrations attained by the infused catecholamines during such investigations have never been delineated. Recently a highly specific and sensitive procedure for the simultaneous fluorometric determination of epinephrine and norepinephrine in plasma was described (4, 5 while they were lying on a bed. Blood pressure and pulse were noted at various intervals. Routinely, 30 ml. blood specimens were drawn from the right antecubital vein into syringes wetted with heparin solution (sterile Liquaemin® Sodium, Organon Inc., Orange, N. J.), and then transferred immediately to cold 40 ml. centrifuge tubes equipped with ground glass stoppers. Specimens were chilled in an ice-water bath until the complete set for the particular experiment had been collected. They were then centrifuged at 700 G for 15 minutes following which the supernatant plasmas were removed and analyzed for epinephrine and norepinephrine as described elsewhere (4, 5). The plasma concentrations of catecholamine reported in this communication are uncorrected for recoveries which had been demonstrated previously to range from 70 to 90 per cent (5).Infusions were automatically terminated after infusion speeds of 30 ,ug. catecholamine per minute had been reached, or if a pulse pressure of 100 mm. Hg or a basal pressure increase of 100 mm. Hg were attained. Cessation of infusions also followed upon request of the subject, report of a persistent headache, or if the subject appeared extremely uncomfortable although willing to continue. RESULTSConstant rate infusions of epinephrine or norepinephrine were characterized by the attainment of steady state plasma concentrations as demonstrated in Figure 1. Although at times fluctuations in the steady state concentrations were observed, particularly for norepinephrine (cf. Curves B, C and E), the data in general were indicative of the maintenance of a dynamic balance between the rate at which the particular catecholamine was added to plasma and the rate at which it was simultaneously removed. Steady states were maintained for up to 65 minutes, the longest period tested. For epinephrine infusions, steady 1935

There are marked hourly variations in the urinary output of sodium, chloride, and potassium in normal subjects. Some of these are clearly related to intake and others are produced by major physiologic adaptations, as changing from the supine to the erect position. However, considerable variations occur from day to day and hour to hour in the fasting supine subject. The purpose of this paper is to report the variations in excretion of Na, Cl, and K in normal subjects at rest and during motionless standing and compare them with the changes produced by cortisone and desoxycorticosterone glucoside (DCG), and after adrenal stimulation by corticotropin (ACTH). METHODSSodium and potassium in urine were measured by the flame photometer (1). Urinary chloride was measured by the silver iodate method (2).Normal healthy college students were used. For three days before the experiments, the subjects were on a low-sodium diet (less than 0.5 Gm. NaCI) and were given 3 Gm. of NaCl orally every three hours. This was a daily intake of 24.5 Gm. NaCl or 422 mEq. We hoped that this high intake of NaCl would inhibit the mechanism normally causing retention of NaCl and thus allow ACTH, cortisone and DCG to have maximum action on salt excretion.Except for water, ad lib., and 3 Gm. of NaCi every three hours, subjects were fasted for 12 hours before the experiment. In most instances, they slept in the laboratory on the night before the experiment. designed to measure the effect of ACTH, cortisone, DCG and tilting on the excretion of Na, Cl, and K. The excretion rates during the first and second hours were compared with the excretion rates for the first and second hours of the control group to be certain that comparable factors were acting during all sets of experiments. Two hours after the experiment started, ACTH, DCG and cortisone were given. In determining whether significant changes had occurred after the use of drugs, comparable hours were compared with those from the control series. RESULTSFasted subjects in bed without medication. Twelve experiments were run on five subjects. The hourly excretion (not recorded here) of Na, K, and Cl from 6:00 a.m. to 12:00 noon varied up and down from day to day and hour to hour in both the same and different subjects. There was no detectable correlation between the initial hourly excretion rate and the ratios Na/Cl, K/Cl, and K/Na. Over the six hours of the experiment, in spite of wide hourly variations, the quantities of Na, K, and Cl excreted progressively increased.The Na/Cl ratio showed little change. The K/Na and K/Cl ratios rose slightly in the first four hours as K excretion increased and then fell back toward the initial values as Na and Cl excretion continued to rise (data not recorded).Intravenous ACTH. Seven experiments were run on four subjects. ACTH (Wilson) was given intravenously in three minutes in doses of 20 units at 8:00 a.m. In the first two hours before ACTH, Na excretion was somewhat less than in the fasted group (p < .05). The excretion of K, Cl, and Na/Cl, K/Cl, and K/Na r...

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