Infusion of ketone bodies to ammonium chloride-loaded acidotic dogs was found to induce significant reduction in urinary excretion of ammonia. This effect could not be attributed to urinary pH variations. Total ammonia production by the left kidney was measured in 25 animals infused during 90 min with the sodium salt of D,L-β-hydroxybutyric acid adjusted to pH 6.0 or 4.2. Ketonemia averaged 4.5 mM/liter. In all experiments the ammonia content of both urine and renal venous blood fell markedly so that ammoniogenesis was depressed by 60% or more within 60 min after the onset of infusion. Administration of equimolar quantities of sodium acetoacetate adjusted to pH 6.0 resulted in a 50% decrease in renal ammonia production. Infusion of ketone bodies adjusted to pH 6.0 is usually accompanied by a small increase in extracellular bicarbonate (3.7 mM/liter). However infusion of D,L-sodium lactate or sodium bicarbonate in amounts sufficient to induce a similar rise in plasma bicarbonate resulted in only a slight decrement in ammonia production (15%). The continuous infusion of 5% mannitol alone during 90-150 min failed to influence renal ammoniogenesis. Infusion of pure sodium-free β-hydroxybutyric acid prepared by ion exchange (pH 2.2) resulted in a 50% decrease in renal ammoniogenesis in spite of the fact that both urinary pH and plasma bicarbonate fell significantly. During all experiments where ketones were infused, the renal extraction of glutamine became negligible as the renal glutamine arteriovenous difference was abolished. Renal hemodynamics did not vary significantly. Infusion of β-hydroxybutyrate into the left renal artery resulted in a rapid decrease in ammoniogenesis by the perfused kidney. The present study indicates that ketone bodies exert their inhibitory influence within the renal tubular cell. Since their effect is independent of urinary or systemic acid-base changes, it is suggested that they depress renal ammoniogenesis by preventing the transformation of glutamine and glutamate into α-ketoglutarate in the mitochondria of the renal tubular cell.
Guy Lemieux, Patrick Vinay, Pierre Robitaille, Gérard E. Plante, Yolande Lussier, Pierre Martin
A method has been described for the direct measurement of proinsulin in human plasma. The method makes use of an insulin-degrading enzyme designated “insulin-specific protease (ISP)”, which is obtained from rat skeletal muscle. Under the conditions used, this enzyme rapidly degrades insulin and insulin-like polypeptides to nonimmunoassayable components, whereas proinsulin and proinsulin cleaved at position B54,55 are not appreciably affected. The incubation of plasma with ISP results in the disappearance of insulin, but not proinsulin, as demonstrated by column chromatography. Immunoassay of the plasma, therefore, before and after incubation, determines the values for the total immunoreactive substance (TIR) and for immunoreactive proinsulin (IRP), respectively. The values obtained for proinsulin levels are reproducible and compare closely with the more complicated column fractionation methods.
Abbas E. Kitabchi, William C. Duckworth, James S. Brush, Martha Heinemann
We present evidence that the hereditable hemolytic disease, hereditary spherocytosis (HS), involves an abnormality in protein of the red cell membrane. Unlike that from normal red cells, lipid-free proteins extracted from HS red cell membranes fail to increase in sedimentation rate when treated with cations; such treatment of normal membrane proteins has been shown by others to cause the formation of microfilaments. That microfilament formation might be defective in HS red cell membranes is supported by observations with vinblastine. This compound, a potent precipitant of filamentous, structure proteins throughout phylogeny, precipitates significantly less HS membrane protein than normal. The resistance of HS membrane protein to changes in conformation by cations is observable at the cellular level as well. That is, both normal and HS red cells agglutinate after repeated washing and suspension in electrolyte-free media. Tiny concentrations of Ca++ (5 × 10-5 M) changes the surfaces of normal cells in such a way as to cause disagglutination; HS red cells resist this change and remain agglutinated unless Ca++ concentrations are increased many-fold.
H. S. Jacob, A. Ruby, E. S. Overland, D. Mazia
The serum-growth hormone response to exercise is greater and occurs earlier in juvenile diabetics than in nondiabetics. A simple exercise test has been devised which unequivocally reveals the growth hormone hypersecretion of juvenile diabetics. Using this procedure we have shown that after a period of exceedingly strict metabolic control of the diabetes, complete normalization of growth hormone secretion is attained. It is concluded that the abnormalities in serum growth hormone found in juvenile diabetics are of a metabolic origin.
Aage Prange Hansen
The influence of alcohol on albumin synthesis was studied in the isolated perfused rabbit liver. Carbonate-14C was used to label the intracellular arginine pool which serves as the precursor of both the carbon of urea and the guanido carbon of arginine in albumin. The control group synthesized albumin at a rate of 33 mg/100 g of wet liver weight during 2.5 hr of perfusion. When alcohol, 220 mg/100 ml, was added to the perfusate, albumin synthesis decreased to between 7 and 11 mg, less than one-third the control rate. The addition of 10 mM tryptophan to perfusates containing alcohol prevented most of the inhibitory effects and albumin synthesis increased to average 24 mg. Further, the addition of alcohol to the perfusate decreased the hepatic protein/DNA ratio from 70 to 54 and the RNA/DNA ratio from 2.3 to 1.8, changes equivalent to those seen after a 24 hr fast. The addition of tryptophan to the perfusate prevented these findings in both instances.
Marcus A. Rothschild, Murray Oratz, Joseph Mongelli, Sidney S. Schreiber
A dysfibrinogenemia (fibrinogen Bethesda) was detected in a 9 yr old male of Mexican-English extraction who had a lifelong history of mild bleeding diathesis. The prothrombin and partial thromboplastin times were moderately prolonged; the thrombin and Reptilase times were markedly prolonged. The plasma fibrinogen level was normal by conventional methods but was markedly reduced by the Clauss method. Results of all other tests for clotting factors, fibrinolysis, antithrombin levels, clot stabilization, and fibrin(ogen) degradation products were normal. The patient's plasma and fibrinogen inhibited the clotting of normal plasma or fibrinogen by thrombin. Family studies revealed that the propositus' mother and two siblings exhibited these abnormalities to a lesser degree and indicated an autosomal dominant inheritance. Fibrinogen Bethesda was similar to normal fibrinogen in the following respects: metabolic turnover time (measured in the propositus' mother); immunodiffusion, ultracentrifugal, electrophoretic (on cellulose acetate or polyacrylamide gel), and chromatographic (on DEAE-cellulose) characteristics; sialic acid content; and aggregation of fibrin monomers. By contrast, fibrinogen Bethesda gave an abnormal immunoelectrophoretic pattern especially when whole plasma (as opposed to purified fibrinogen) was examined, and it showed a pronounced decrease in the rate of fibrinopeptide release by thrombin. This decrease, which was shown to involve both fibrinopeptides A and B, distinguishes fibrinogen Bethesda from previously reported dysfibrinogenemias.
H. R. Gralnick, H. M. Givelber, J. R. Shainoff, J. S. Finlayson
Unanesthetized sheep and dogs, previously fitted with indwelling catheters in the aorta, lower vena cava, mesenteric, portal, left hepatic and jugular veins, were given constant intravenous infusions of lymph in which the chylomicron lipids were variously labeled with 3H or 14C. Para-aminohippuric acid was infused into the mesenteric venous catheter for measurement of portal and hepatic venous blood flow. In some animals, alternately labeled free fatty acids bound to albumin were mixed with the lymph to be infused. In both species, chylomicron triglyceride fatty acids were taken up in the region drained by the lower vena cava and portal vein and free fatty acids derived from hydrolysis of these triglycerides were extensively recycled in the blood. Direct uptake of triglyceride fatty acids also occurred in liver and accounted for about 10% of the total triglyceride fatty acids removed from the blood in sheep and 22% in dogs. In sheep, 10% and, in dogs, about 40% of these triglyceride-fatty acids were released into the blood as free fatty acids. The free fatty acids recycled from various regions accounted for a substantial fraction of the chylomicron fat eventually deposited in each tissue. Uptake of chylomicron cholesterol from the blood of sheep occurred primarily in liver and to a small extent in certain tissues drained by the portal vein. The results obtained, together with other available data, demonstrate that chylomicron triglycerides are removed primarily in extrahepatic tissues of both species, while the liver removes cholesterol contained in chylomicron “skeletons” from which most of the triglycerides have been removed. The quantitative differences between transport of chylomicron lipid in sheep and dogs may be related to known differences in the structure of their hepatic sinusoids.
E. N. Bergman, R. J. Havel, B. M. Wolfe, T. Bøhmer
The importance of antigen site density has been studied by means of a model passive hemolysis system using red cells coupled with sulfanilic acid groups. Relative site numbers were estimated from the covalent linkage of sulfanilic acid-35S to red cell membrane protein, and the effective antigen site number was determined with 125I-labeled rabbit IgG anti-sulfanilic acid (anti-S).
Leon W. Hoyer, Norma C. Trabold
Bilirubin-14C production was measured in rats transfused with labeled erythrocytes from animals with iron deficiency anemia, a condition associated with ineffective erythropoiesis. With labeled reticulocytes harvested 1 day after the administration of glycine-2-14C, conversion of hemoglobin-14C to bilirubin averaged 47.3% over the 3 days of observation; the corresponding value for reticulocytes from normal rats was only 1.7%. Findings were not altered by splenectomy. Bilirubin-14C production fell to 35.8% with iron-deficient cells harvested 3 days after glycine-14C administration, and declined further to a plateau averaging 25% with cells labeled 5, 7, 10, or 15 days earlier. The latter values still far exceed those for mature erythrocytes from normal animals.
Stephen H. Robinson, Ellen Koeppel
A method has been developed for measuring the adhesion of platelets to purified collagen fibers obtained from bovine tendon. This method differs from others in that: (a) platelet adhesion is measured in the absence of platelet aggregation; (b) platelet-rich plasma collected in ACD (acid citrate dextrose) or EDTA, or washed platelets can be employed; (c) adherent platelets are enumerated directly; (d) erythrocytes and leukocytes do not adhere.
Bruce Lyman, Lawrence Rosenberg, Simon Karpatkin
A method is described for preparation of a solid immunoadsorbent suspended in an agar gel. The immunoadsorbent in gel retains its specificity. Rabbits were injected with antibody or antigen, and an extracorporeal circulation was established through columns or funnels coated with such immunoadsorbents. It was shown that either antibody or antigen can be specifically and rapidly removed, and that no measurable amounts of antigen from the immunoadsorbent were released into the animals.
Isaac Schenkein, Jean-Claude Bystryn, Jonathan W. Uhr
The effect of intravenous infusion of isoproterenol on myocardial oxygen consumption (ṀVo2) was studied in 10 intact and anesthetized dogs before and after inhibition of lipolysis. In five dogs lipolysis was inhibited by nicotinic acid or beta pyridyl carbinol and in five other dogs by high plasma glucose concentrations. In spite of similar mechanical responses to isoproterenol, as evidenced by left ventricular pressure, maximal rate of rise of left ventricular pressure (dP/dt), heart rate and cardiac output, augmentation of ṀVo2 was larger before (on average 7.6 ml/min·100 g) than after inhibition of lipolysis either by antilipolytic drugs (on average 4.5 ml/min·100 g) (P < 0.005), or by high plasma glucose concentrations (on average 4.3 ml/min·100 g) (P < 0.02). As mechanical responses to isoproterenol were similar before and after inhibition of lipolysis, it is concluded that the additional rise in ṀVo2 with intact lipolysis was caused by a metabolic stimulation by high concentrations of free fatty acids.
Ole Danbolt Mjøs
The rate of clotting and the rate of development and degree of turbidity after addition of thrombin to plasma or purified fibrinogen from a patient with fibrinogen Baltimore was delayed when compared with normal, especially in the presence of low concentrations of thrombin. Optimal coagulation and development of translucent, rather than opaque, clots occurred at a lower pH with the abnormal fibrinogen than with normal. Development of turbidity during clotting of the abnormal plasma or fibrinogen was less than normal at each pH tested, but was maximal in both at approximately pH 6.4. The physical quality of clots formed from fibrinogen Baltimore was abnormal, as demonstrated by a decreased amplitude on thromboelastography. The morphologic appearance of fibrin strands formed from fibrinogen Baltimore by thrombin at pH 7.4 was abnormal when examined by phase contrast or electron microscopy, but those formed by thrombin at pH 6.4 or by thrombin and calcium chloride were similar to, though less compact, than normal fibrin. The periodicity of fibrin formed from fibrinogen Baltimore was similar to normal and was 231-233 Å.
Eugene A. Beck, John R. Shainoff, Alfred Vogel, Dudley P. Jackson
The effect of intra-aortic counterpulsation (IACP, 22-94 hr) on hemodynamics and cardiac energetics was evaluated in 10 patients in shock after acute myocardial infarction. The data clearly indicate that IACP improves myocardial oxygenation, enhances peripheral perfusion, and probably improves myocardial contractility in the severely diseased heart.
Hiltrud Mueller, Stephen M. Ayres, E. Foster Conklin, Stanley Giannelli Jr., James T. Mazzara, William T. Grace, Thomas F. Nealon Jr.
In studies with pyridoxine and other B6 compounds in blood, the active forms pyridoxal and pyridoxal phosphate were measured by differential assays using Lactobacillus casei. Red cell uptake of tritiated pyridoxine was also measured. A new metabolic pathway for conversion of pyridoxine to active forms was demonstrated in red cells.
Barbara B. Anderson, Catherine E. Fulford-Jones, J. Anthony Child, Michael E. J. Beard, Christopher J. T. Bateman
Intestinal absorption of the monoglutamate form of the principal dietary and circulating folate compound, 5-methyltetrahydrofolic acid (5-MTHF), was studied in the rat utilizing a synthetic highly purified radiolabeled diastereoisomer. Chromatography confirmed that the compound was not altered after transfer from the mucosa to the serosa. Accumulation against a concentration gradient was not observed in duodenal, jejunal, or ileal segments at 5-MTHF concentration from 0.5 to 500 nmoles/liter. Unidirectional transmural flux determination also did not indicate a significant net flux. Mucosal to serosal transfer of 5-MTHF was similar in all segments of the intestine and increased in a linear fashion with increased initial mucosal concentrations. Further, no alteration in 5-MTHF transfer was found when studied in the presence of metabolic inhibitors or folate compounds.
Williamson Strum, Peter F. Nixon, Joseph B. Bertino, Henry J. Binder
Bile salts and phospholipids are both required to solubilize biliary cholesterol. Since interruption of the enterohepatic circulation (EHC) depletes bile of bile salts, we have examined in the rhesus monkey the effects of controlled interruption of the EHC on biliary secretion of bile salt, phospholipid, and cholesterol and on the relative proportions of these components in bile.
R. Hermon Dowling, Eberhard Mack, Donald M. Small
The clinical and metabolic effects of porcine calcitonin were assessed in six patients with Paget's disease and two patients with osteoporosis under metabolic balance conditions. The administration of calcitonin for 4-17 wk resulted in an amelioration of the clinical phenomena associated with Paget's disease, including bone pain, increased skeletal vascularity, congestive heart failure, and neurologic deficits secondary to skeletal impingement. The major metabolic effects of calcitonin in Paget's disease included the induction of positive calcium balance of +50 to +240 mg/day, reduction in hyperphosphatasia and hydroxyprolinuria of 15 to 60%, and a deceleration of radiocalcium turnover by 12 to 46%. Natriuresis, phosphaturia, and reduced urinary calcium excretion were observed, whereas sustained hypocalcemia and hypophosphatemia did not occur. The administration of porcine calcitonin was not associated with adverse objective or subjective reactions, toxic effects, or allergic phenomena. There was no evidence of antibody formation or loss of therapeutic potency. Although the response of individual patients with Paget's disease varied widely, the data indicate that calcitonin, presumably through its skeletal anti-resorptive action, is able to reduce skeletal turnover and volume in Paget's disease, and thereby improve the associated clinical and metabolic abnormalities. Long term therapeutic studies in progress suggest that prolonged periods of control of the generalized condition may be feasible.
Florence Shai, Richard K. Baker, Stanley Wallach
The effect of human growth hormone (HGH) on the N, P, Na, and K balance, and on the body weight (BW) of three groups of subjects was measured. In group I were nine cases (age 6-69) with HGH deficiency; in group II, eight cases (age 9-79) with normal endogenous HGH; in group III, four cases with myotonic dystrophy (age 45-51). After a 7 day control period, the hormone was administered for 7 days. Each subject was tested with three doses of HGH: dose A, 0.0168 U/kg BW3/4 per day; dose B, 0.0532 U/kg BW3/4 per day; dose C, 0.168 U/kg BW3/4 per day.
Daniel Rudman, Samuel B. Chyatte, Joseph H. Patterson, Glynda G. Gerron, Irma O'Beirne, Joan Barlow, Peter Ahmann, Ashby Jordan, Robert C. Mosteller
The peripheral vascular response to severe exercise was studied in 11 healthy conscious dogs instrumented with Doppler ultrasonic flow probes on the mesenteric, renal, and iliac arteries, and miniature pressure gauges in the aorta. The response to severe exercise was restudied in six of these dogs after recovery from a second operation producing complete heart block by the injection of formalin into the atrioventricular (AV) node. Three of these dogs also exercised while their ventricles were paced at rates of 100/min and 200/min. The untethered normal dogs ran at speeds of 15-25 miles/hr behind a mobile recording unit for a distance averaging 1.5 miles, while continuous measurements of arterial blood pressure and blood flow were telemetered and recorded on magnetic tape. Severe exercise in normal dogs increased heart rate from 84 to 259/min, arterial pressure from 89 to 140 mm Hg, flow resistance in the mesenteric and renal beds by 59 and 52% respectively, and iliac blood flow 479% above control, while mesenteric and renal blood flows remained constant and iliac resistance decreased by 73%.
Stephen F. Vatner, Charles B. Higgins, Saxon White, Thomas Patrick, Dean Franklin
10 families with cystinuria were investigated by measuring: (a) quantitative 24 hr urinary excretion of amino acids by column chromatography; (b) endogenous renal clearances of amino acids and creatinine; (c) intestinal uptake of 34C-labeled L-cystine, L-lysine, and L-arginine using jejunal mucosal biopsies; (d) oral cystine loading tests. All four of these were studied in the probands and the first two in a large number of the family members.
Claude L. Morin, Margaret W. Thompson, Sanford H. Jackson, Andrew Sass-Kortsak
The antiepileptic action of diphenylhydantoin (DPH) has been explained by two different theories: (a) that DPH stimulates the Na-K pump; (b) that DPH specifically blocks the passive translocation of sodium. Since electrophysiological experiments have recently suggested abnormal synaptic mechanisms as the basis for epileptogenic discharges, the action of DPH on K transport within synaptic terminals isolated from “normal” rat brain cortex was examined directly. A rapid filtration technique was used to assess in vitro potassium transport within synaptosomes. In vivo DPH did not significantly change endogenous K content within synaptosomes. With sodium (50 mM) and potassium (10 mM) concentrations optimal for Na-K pump activity, in vivo and in vitro DPH (10-4 M) had minimal or no effects on total K uptake. DPH stimulated potassium uptake within synaptosomes under two situations: (a) at high sodium (50-100 mM) and low potassium (less than 2 mM) concentrations; (b) when synaptosomes were incubated with ouabain (10-4 M) 50 mM Na and 10 mM K. In both situations, K was leaking out of synaptic terminals and the enhancement in net K uptake roughly corresponded to the ouabain inhibitable segment. In the absence of ouabain, the stimulatory effects of DPH were not observed when K was 2 mM or higher and when Na was 10 mM or lower. The stimulatory effects of in vitro DPH appeared over a range of concentrations from 10-4 to 10-10 M while single intraperitoneal injections of DPH had to be administered for 2 days before its effects were observed on synaptosomal K transport. The present data provided direct evidence for DPH stimulation of active potassium transport within synaptosomes under ionic conditions simulating the depolarized state. At other ionic conditions, DPH had inhibitory or no effects on K uptake. Although the results do not specify whether the effects of DPH on the Na-K pump are direct or indirect, they suggest that the action of DPH depends upon the state of the membrane and the specific ionic environment.
Antonio V. Escueta, Stanley H. Appel
D-Amino acid oxidase and L-amino acid oxidase have been measured in sucrose homogenates of polymorphonuclear leukocytes (PMN) obtained from guinea pigs and humans. Subcellular distribution patterns and studies on latency indicate that these oxidases are soluble enzymes. Their hydrogen peroxide-generating capacity was verified. Chronic granulomatous disease PMN, which lack a respiratory burst and fail to generate H2O2 during phagocytosis and do not kill catalase positive bacteria, had peroxide-generating amino acid oxidase activity equal to that found in PMN homogenates from patients with bacterial infections. The precise metabolic and bactericidal role of amino acid oxidases in PMN remains uncertain.
Marlene R. Eckstein, Robert L. Baehner, David G. Nathan
Suppression of pancreatic glucagon secretion by hyperglycemia is a characteristic of normal alpha cell function. However, in diabetic subjects, plasma glucagon is normal or high despite hyperglycemia. It seemed possible that the presence of glucose or its metabolites within the alpha cell might be essential for suppression of glucagon secretion, and that in diabetes an intracellular deficiency of glucose secondary to insulin lack might be responsible for the nonsuppressibility. The present study was designed to determine the effect upon glucagon secretion of blockade of glucose metabolism and of experimental insulin deficiency.
Walter A. Müller, Gerald R. Faloona, Roger H. Unger
Progeria is an autosomal recessive disorder showing precocious senility. The cultured skin fibroblast from both the homozygous affected individual and the heterozygous parents can be distinguished from normals by decreased cell growth in culture. Mitotic activity, DNA synthesis, and cloning efficiency are markedly reduced.
B. Shannon Danes
A millipore diffusion chamber system was used to cultivate mouse marrow in the abdomens of irradiated and unirradiated host mice for 24 hr. When the irradiated hosts were 72, 96, or 120 hr postirradiation, the number of blasts and promyelocytes in the implanted chambers after cultivation was greater than those in the same marrow cultivated in unirradiated hosts. These data indicate that in vivo, there is stimulation of granulocytopoiesis by a diffusible factor or factors.
G. Rothstein, E. H. Hügl, C. R. Bishop, J. W. Athens, H. E. Ashenbrucker