Ketonuria has been observed in alcoholics. To study the mechanism of this effect, healthy, volunteers were given adequate diets (36% of calories as lipid and 15% as protein) for 18 days, with isocaloric replacement of carbohydrate (46% of calories) by either ethanol or additional fat. The latter resulted in a high fat diet, with 82% of calories as lipid. After about 1 wk of alcohol, massive and persistent ketonuria developed. Compared with the control period, there was a 30-fold increase in fasting blood acetoacetate and β-hydroxybutyrate (P < 0.001). With the high fat diet, acetoacetate and β-hydroxybutyrate increased 8- to 10-fold (P < 0.001). In the postprandial state, ethanol also induced hyperketonemia, but less markedly than when ethanol followed an overnight fast. With low fat diets (5% of calories), alcohol (46% of total calories) did not induce ketonuria or hyperketonemia, suggesting that a combination of alcohol and dietary fat is necessary. The addition of alcohol to rat liver slices did not affect ketogenesis. In rats pretreated with alcohol for 3 days, however, ketonemia developed, hepatic glycogen was decreased, and liver slices (incubated with palmitate-14C and glucose) had a significant increase in acetoacetate production, when compared to carbohydrate pretreated controls. Alcohol pretreatment or addition of alcohol in vitro had no effect on acetoacetate utilization by rat diaphragms, and decreased only slightly the conversion of β-hydroxybutyrate-14C to 14CO2. Thus, the hyperketonemia and ketonuria observed after alcohol consumption cannot be attributed to an immediate effect of alcohol, but is the consequence of a delayed change in intermediary metabolism characterized by increased hepatic ketone production from fatty acids, possibly linked to ethanol-induced glycogen depletion and depression of citric acid cycle activity.
André Lefèvre, Howard Adler, Charles S. Lieber
Monosodium urate deposits almost exclusively in the connective tissues of patients with gout. Acetone dried homogenates of bovine nasal cartilage, but not of other tissues, markedly enhances the solubility of urate in buffers having molarities and hydrogen ion concentrations similar to that of most body fluids. The components of cartilage responsible for this effect are the proteinpolysaccharides, compounds of protein and chondroitin sulfate, called PPL. A progressive increase in PPL concentration results in a corresponding increase in urate solubility. If, on the other hand, unbound chondroitin sulfate or PPL digested by trypsin is used, then no significant augmentation of urate solubility occurs indicating that the integrity of the molecule is essential. One subfraction of PPL, PPL5, causes an even more exaggerated response while another, PPL3, causes a lesser one. These proteinpolysaccharide macro-molecules also inhibit the crystallization of urate from a supersaturated medium. The mechanism of the solubilizing phenomenon is not known. It is suggested that some type of physical or chemical binding is responsible. When, as a result of normal or accelerated connective tissue turnover, PPL is enzymatically destroyed, urate crystals then precipitate from the saturated tissue fluids.
Warren A. Katz, Maxwell Schubert
Serum samples were obtained from 21 normal human fetuses after therapeutic abortion for psychiatric indications. Fetal crown-rump length ranged from 5.2 to 22.5 cm, corresponding to the gestational age of 65-168 days.
Arnold H. Greenberg, Paul Czernichow, Richard C. Reba, John Tyson, Robert M. Blizzard
Active sodium transport (outflux or efflux) in red blood cells generally has been measured by assessing the amount of outflux inhibited by digitalis glycosides (outflux-fraction I). The presence of a ouabain-uninhibited sodium outflux (outflux-fraction II) attributable either to a second active transport mechanism or to exchange diffusion has been the subject of recent investigations. In the present study a variety of transport inhibitors, including ouabain, ethacrynic acid, furosemide, oligomycin, and amiloride, were studied for their effects on these components of sodium transport in RBC.
Michael J. Dunn
In order to investigate the mechanism of Na and K transport, rabbit cortical collecting tubules were perfused in vitro and the concentrations of Na and K in lumen and bathing fluid and the transtubular electrical potential difference (PD) were measured.
Jared J. Grantham, Maurice B. Burg, Jack Orloff
Plasma lipoproteins from patients with familial lecithin:cholesterol acyltransferase (LCAT) deficiency have been fractioned by preparative ultra-centrifugation and gel filtration and their lipid content and reactivity studied. All of the lipoproteins are abnormal with respect to lipid concentration or relative lipid content. The low density lipoproteins (LDL) and high density lipoproteins (HDL) appear to react normally with partially purified LCAT from normal plasma. Also, the lipids of the very low density lipoproteins (VLDL) and LDL, like those of the corresponding lipoproteins of normal plasma, are indirectly altered by the action of LCAT on normal HDL. Thus, during incubation in vitro VLDL cholesteryl ester is increased and VLDL triglyceride is decreased, as described by others for VLDL from hyperlipemic plasma, and both the unesterified cholesterol and lecithin of the VLDL and LDL are decreased. The patients' VLDL and LDL are abnormal, however, in that they lose unesterified cholesterol and lecithin to normal HDL in the absence of LCAT. Also, the patients' HDL lose these lipids to erythrocyte membranes in the absence of the enzyme.
John A. Glomset, Kaare R. Norum, Weiling King
The unique membrane characteristics of the thin descending limb of Henle (DLH) play an integral part in the operation of the countercurrent system. We examined these properties in vitro by perfusing isolated thin descending limbs of rabbits. Active transport of NaCl was ruled out by failure to demonstrate either net transport or transmembrane potential difference when perfusing with isosmolal ultrafiltrate of the same rabbit serum as the bath. Transmembrane potential was zero, and net fluid transport was -0.07 ±0.06 nl mm-1 min-1, which also is not significantly different from zero. Passive permeability coefficient for Na(PNa) was determined from the disappearance rate of 22Na from isosmolal perfusion solution. PNa was surprisingly low, 1.61 ±0.27 × 10-5 cm sec-1, a figure which is significantly less than PNa in the proximal convoluted tubule (PCT). Reflection coefficient for NaCl (σNaCl) was measured by perfusing the tubule with Na-free raffinose solution in a bath of rabbit serum to which sufficient NaCl was added to obtain conditions of zero net fluid movement. The measured σNaCl of 0.96 ±0.01 is significantly greater than σNaCl in the PCT. Water permeability to osmotic gradients (Lp) was determined by perfusing with ultrafiltrate of rabbit serum in a bath made hyperosmotic by addition of either 100 mOsm raffinose or NaCl. Lp with raffinose was 1.71 ±0.15 × 10-4 ml cm-2 sec-1 atm-1 and with NaCl 1.62 ±0.05 × 10-4 ml cm-2 sec-1 atm-1, indicating much greater water permeability than in the PCT. In each case the measured increase in osmolality of the collected fluid was primarily due to water efflux without significant influx of solute.
Juha P. Kokko
Serum FSH and LH levels in 104 patients with disorders of sexual development were determined by radioimmunoassay and compared with serum FSH and LH levels in 164 normal individuals.
Robert Penny, Harvey J. Guyda, Alice Baghdassarian, Ann J. Johanson, Robert M. Blizzard
Chylomicron (primary particles) were detected by polyvinylpyrollidone (PVP) flocculation in plasma collected after an overnight fast from eight hyperlipemic subjects with broad-β disease (type III hyperlipoproteinemia). The composition of these chylomicrons was abnormal: relatively poor in triglyceride and rich in cholesterol, giving rise to a triglyceride/cholesterol ratio of < 3.0 in all cases, uniformly below the ratio in chylomicrons from eight fasting subjects with mixed lipemia. By contrast, at the peak of alimentary lipemia following an oral fat load (2 g/kg), chylomicrons from broad-β subjects had normal, triglyceride-rich composition (triglyceride/cholesterol = 14.0) and resembled chylomicrons from subjects with mixed lipemia, endogenous lipemia, and familial hypercholesterolemia after similar fat loads. As the alimentary lipemia cleared, chylomicrons remaining in broad-β subjects 14-24 hr after the fat load were again rich in cholesterol. However, a similar degree of cholesterol enrichment was observed in chylomicrons from the subjects with familial hypercholesterolemia, while only a minor increase in cholesterol was recorded in chylomicrons from subjects with mixed or endogenous lipemia. Parallel studies of changes in chylomicron composition during in vitro incubation of whole plasma and of Sf > 400 with Sf < 400 lipoproteins from subjects with the different forms of hyperlipoproteinemia revealed equal cholesterol enrichment of chylomicrons from a subject with mixed lipemia and from a subject with broad-β disease in media of equivalent cholesterol content. These experiments suggested neither excessive avidity of chylomicrons for cholesterol uptake nor excessive influence of Sf < 400 lipoproteins upon chylomicron composition in broad-β disease.
William R. Hazzard, Daniel Porte Jr., Edwin L. Bierman
The dynamic and metabolic performance of rats conditioned by a swimming program (CH) and hearts of sedentary rats (SH) was studied in an isolated working rat heart apparatus. Heart rate, filling pressure, and afterload were controlled or kept constant, and heart weights were comparable in both groups.
Somsong Penpargkul, James Scheuer
Iron transport by everted duodenal sacs in vitro was studied in mice with sex-linked anemia (gene symbol sla) (an inherited iron deficiency anemia), in normal mice, and in normal mice on iron-deficient and iron supplemented diets. Although the over-all mucosal uptake of iron was the same in sla and normal sacs, transport of iron to the inside of the sac was much decreased in sla. The iron transport defect in sla was emphasized by the fact that genotypically normal mice on an iron-deficient diet demonstrated greatly increased iron transport. Electrophoretic analysis of protein extracted from sla and normal sacs showed only one iron-binding fraction. The sla and normal fractions had the same mobility and corresponded in position to the major band of horse ferritin.
John A. Edwards, Robin M. Bannerman
The kinetics of the depletion of plasma fibrinogen were studied in seven patients who received fibrinogen-131I 1 hr before an intravenous injection of the coagulating enzyme (CE) derived from the venom of the pit viper, Agkistrodon rhodostoma. Disappearance of the clottable radioactivity labeled fibrinogen from the circulation conformed to an exponential decay with an average half-life of 0.85 hr. The mean clearance rate for protein-bound radioactivity, composed of fibrinogen and it's split products, was 12% of the intravascular pool per hour. The breakdown products of fibrin produced by CE inhibited polymerization of fibrin in vitro.
W. R. Bell, E. Regoeczi
This paper describes a method for isolating and studying the metabolism of human eccrine sweat glands. (a) Electron microscopy of glands which had been isolated and then incubated for an hour revealed no apparent alteration in morphology. (b) Known variation in gland size (male > female > children) was reflected in the relative rates of lactate production. (c) Lactate production was approximately 1.5 nmoles/gland per hr in the absence of glucose and rose to 2.7 at physiological concentrations of glucose (5.6 mmoles/liter). This amount of lactate production agrees well with the amounts found in sweat. (d) Both adrenergic (epinephrine) and cholinergic (methacholine) stimuli increased lactate production. (e) Glycogen depletion was demonstrated during incubation. (f) O2 consumption was measured and aerobic metabolism was found to account for less than 1% of the energy derived from anaerobic pathways.
S. Wolfe, G. Cage, M. Epstein, L. Tice, H. Miller, R. S. Gordon Jr.
Hemodynamics and myocardial metabolism were evaluated in 18 patients in cardiogenic shock following acute myocardial infarction. The response to l-norepinephrine was studied in seven cases and the response to isoproterenol in four cases. Cardiac index (CI) was markedly reduced, averaging 1.35 liters/min per m2. Mean arterial pressure ranged from 40 to 65 mm Hg while systemic vascular resistance varied widely, averaging 1575 dyne-sec-cm-5. Coronary blood flow (CBF) was decreased in all but three patients (range 60-95, mean 71 ml/100 g per min). Myocardial oxygen consumption (MVO2) was normal or increased ranging from 5.96 to 11.37 ml/100 g per min. Myocardial oxygen extraction was above 70% and coronary sinus oxygen tension was below 22 mm Hg in most of the patients. The detection of the abnormal oxygen pattern in spite of sampling of mixed coronary venous blood indicates the severity of myocardial hypoxia. In 15 studies myocardial lactate production was demonstrated; in the remaining three lactate extraction was below 10%. Excess lactate was present in 12 patients. During l-norepinephrine infusion CI increased insignificantly. Increased arterial pressure was associated in all patients by increases in CBF, averaging 28% (P < 0.01). Myocardial metabolism improved. Increases in MVO2 mainly paralled increases in CBF. Myocardial lactate production shifted to extraction in three patients and extraction improved in three. During isoproterenol infusion CI increased uniformly, averaging 61%. Mean arterial pressure remained unchanged but diastolic arterial pressure fell. CBF increased in three patients, secondary to decrease in CVR. Myocardial lactate metabolism deteriorated uniformly; lactate production increased or extraction shifted to production. In the acute state of coronary shock the primary therapeutic concern should be directed towards the myocardium and not towards peripheral circulation. Since forward and collateral flow through the severely diseased coronary bed depends mainly on perfusion pressure, l-norepinephrine appears to be superior to isoproterenol; phase-shift balloon pumping may be considered early when pharmacologic therapy is unsuccessful.
Hiltrud Mueller, Stephen M. Ayres, John J. Gregory, Stanley Giannelli Jr., William J. Grace
Fractional catabolic rates of iodine-labeled plasma albumins and fibrinogens have been measured in experiments of a few hours duration in adult rabbits. The method used which is based on release of labeled iodide from the protein gives accurate estimates of catabolic rates (expressed as fractions of the plasma protein pool catabolized per day) after 36 hr without the need for urine collections. At earlier times and using undenatured albumin, fractional catabolic rates increased steadily from approximately 10% per day in the first few hours to a constant 20-25% per day after 24 hr. Fibrinogen values which started at 15% plateaued after 24 hr at 30-35% per day. The fractional synthesis rate of albumin, measured with 14C-labeled carbonate in the first 6 hr when the short-term fractional catabolic rate was 10.2% agreed with the 36 hr plateau value of 29% per day. The presence of traces of denatured or polymerized proteins was revealed by high initial fractional catabolic rates, and in a few experiments biological screening in another animal was not fully effective in removing them. On the other hand, some labeled albumins showed no traces of denatured protein even without biological screening. Fibrinogen polymer was catabolized rapidly and behaved like denatured or incipiently clotted fibrinogen. Irradiation of albumin produced a marked increase in early fractional catabolic rates, and some proteins after prolonged storage and labeling behaved similarly. Alternative theories to explain the low fractional catabolic rates in the first 24 hr are considered. Since radioautographic experiments failed to provide evidence for retention of labeled proteins or their nondiffusible breakdown products inside catabolic cells, preference is given to the view that catabolism occurs in a pool of significant protein content which is either a subunit of the extravascular pool or is independent and sandwiched between the plasma and extravascular pools. Earlier hypotheses concerning small catabolic pools in which protein specific activities approximate closely to plasma values at the same time are considered to be no longer tenable.
A. S. McFarlane, A. Koj
A new method is described for the detection of variations in the release rate of all iodinated products by the thyroid gland in man. 125I was employed to endogenously label the thyroid gland, and a parenterally administered 131I thyroxine dose was used to generate a 131I reference source. Thyroidal iodine release activity was quantitatively assessed by the measurement of variations in 125I/131I ratio values obtained in timed urine samples. Diurnal variation in thyroid release patterns was observed in euthyroid subjects which was promptly suppressed by exogenous triiodothyronine administration and was simulated by the intramuscular injection of 0.25-0.50 U of bovine thyrotropin. The zenith value occurred at 4:00 a.m. ±3.4 hr (SD) and the nadir at 5:00 p.m. ±3.6 hr. The absence of a diurnal pattern in patients with thyrotoxicosis and in secondary hypothyroidism indicated that this diurnal fluctuation was under thyrotropin (TSH) regulation. This new method also promises to be a useful tool for the study of the intrathyroidal recycling of iodide from the iodotyrosine pool and the detection of factors which may acutely alter thyroid function.
John T. Nicoloff
The diurnal variation in thyroidal iodine release previously observed in euthyroid subjects appears to correlate with variations in serum immunoassayable thyrotropin (TSH). The hypothesis is advanced that this diurnal rhythm seems to be primarily regulated by a negative feedback action of circulating hydrocortisone. The administration of maintenance doses of hydrocortisone to patients with primary adrenal insufficiency and pharmacological doses to euthyroid subjects was accompanied by an acute suppression in both thyroidal iodine release and serum TSH values. An escape from glucocorticoid suppression was observed to occur in 2 or 3 days with the resumption of a near-normal thyroidal iodine release rate but was accompanied by a dampening or absence of the normal diurnal rhythm. Withdrawal of pharmacological doses of glucocorticoids in euthyroid subjects and maintenance doses in primary hypoadrenal patients was accompanied by transient stimulation of both serum TSH and thyroidal iodine release values. The study of a patient before and after cryohypophysectomy indicated that the rebound response in thyroid release after steroid withdrawal may be a useful testing procedure to indirectly assess the hypothalamicpituitary reserve capacity of TSH.
John T. Nicoloff, Delbert A. Fisher, Milo D. Appleman Jr.
This is the first report of a male with 17α-hydroxylase deficiency resulting in male pseudohermaphroditism, ambiguous external genitalia, absence of male secondary sexual characteristics, and gynecomastia at puberty. Diagnosis was based on extensive studies of steroid metabolism including the following: low urinary excretion of 17-ketosteroids and 17-hydroxycorticoids which did not increase after ACTH; no response of very low plasma testosterone and dehydroepiandrosterone to adrenocorticotropin (ACTH) or chorionic gonadotropin; and low urinary aldosterone and plasma renin which increased after dexamethasone. Secretion rates of 17-hydroxylated steroids, cortisol (F) and 11-desoxycortisol (S), were very low while desoxycorticosterone (DOC) and corticosterone (B) secretion rates were increased sevenfold. Results expressed as milligrams per meter squared per day were as follows: F, 1.3; S, 0.023; DOC, 0.35; and B, 16 (mean normal values were F, 7.5; S, 0.26; DOC, 0.055, and B, 2.2). Plasma gonadotropins were markedly increased (FSH, 106; LH, 364 mIU/ml). Testicular biopsies revealed interstitial-cell hyperplasia and early spermatogenesis. Karyotype was 46/XY. Pedigree showed no other affected member. At laparotomy ovaries, uterus, and fallopian tubes were absent, vas deferens was incomplete, and prostate was present. External genitalia consisted of small phallus, bifid scrotum, third-degree hypospadias, and small vagina. At puberty there was no growth of body hair or phallic enlargement. Biopsy of marked gynecomastia showed both ducts and acini. Testosterone administration produced virilization. Sexual ambiguity demonstrates strong dependence of external genitalia on androgens for male differentiation. Suppression of Müllerian structures occurred despite female levels of testosterone indicating this step in male differentiation is not testosterone dependent. Pubertal breast development in this male supports the concept of femaleness during ontogeny unless counteracted by male factors. Diagnosis of other adrenocortical enzymatic deficiencies is excluded by the steroidal studies. The clinical response to testosterone excludes testicular feminization. Deficiency of 17-hydroxylation must be added to the cause of male pseudohermaphroditism.
Maria I. New
Glucose intolerance has been observed following diphenylhydantoin (DPH) intoxication. Because of this association between DPH and hyperglycemia, the effect of DPH on insulin release in vitro using preparations of isolated islets of Langerhans and pancreatic pieces was examined. In concentrations identical with those considered necessary for adequate anticonvulsant therapy in man, DPH markedly decreases the insulin secretory response of pancreatic pieces to methacholine, 1 μg/ml, tolbutamide, 250 μg/ml, and glucose, 200 mg/100 ml, without any demonstrable alteration in the oxidative conversion of glucose-1-14C or glucose-6-14C to 14CO2 by isolated islets. This DPH-induced inhibition of insulin secretion is not reversed by higher concentrations of glucose (600 mg/100 ml) or by increasing concentrations of extracellular calcium ion (4-6 mmoles/liter). 0.1 mM potassium and 10-4 M ouabain, however, effectively restore the DPH-induced block of insulin secretion in pancreatic pieces. 60 mM potassium ion, on the other hand, not only restores the insulin secretory response to glucose (200 mg/100 ml) but results in an added stimulation of insulin secretion in the presence of DPH. In the presence of DPH, 22Na accumulation by isolated islets is decreased by 26-40% as compared with controls. Such evidence is considered to indirectly support the postulate that the electrophysiological properties of DPH on the pancreas are due to a stimulation of the membrane sodium-potassium-magnesium ATPase.
J. Stephen Kizer, Mario Vargas-Cordon, Klaus Brendel, Rubin Bressler
Homogenates of human platelets can mediate the synthesis of phosphatidylinositol from myoinositol and cytidine diphosphate diglyceride. The cytidine diphosphate diglyceride: myoinositol, phosphatidyl transferase activity is particulate-bound, and the highest specific activity is found in the membrane fraction. The production of phosphatidylinositol is decreased by sulfhydryl-binding agents, and the addition of thiols to the platelet homogenates increases the enzymatic activity. The reaction exhibits a pH optimum of 8.5-9.0. Divalent cations stimulate the reaction, and manganous chloride was the most effective of those investigated. The Km of the enzyme for myoinositol is 0.27 mM, and the Km for cytidine diphosphate diglyceride is 0.53 mM. The enzymatic activity of platelets isolated from patients with several diseases known to interfere with platelet clotpromoting function is similar to the enzymatic activity of platelets from normal donors.
Charles T. Lucas, Frank L. Call II, William J. Williams