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Subtotal pancreatectomy in the rat was performed by a new method. Except for a small remnant along the splenal hilus, the gland was completely removed. Exocrine pancreatic insufficiency was confirmed by fat and nitrogen malabsorption. A moderate diabetes mellitus was seen. Insulin substitution or diet restriction was unnecessary. The absorption of vitamin B12 after oral administration of 10 ng 57CoB12 was 5.0 +/- 0.2 (ng 57CoB12 +/- S.E.M.) in unoperated rats and 5.1 +/- 0.1 in pancreatectomized rats (p greater than 0.5). Pancreatic extract (PE) (100 mg) increased the absorption of 57CoB12 in unoperated rats (p less than 0.01), but not in pancreatectomized rats (p greater than 0.2). PE (300 mg) reduced the absorption in unoperated rats (p less than 0.01). The results indicate that an optimal amount of pancreatic secretion may stimulate the absorption of vitamin B12.

Pancreatic extract (PE) contained small-molecular, thermo-stable as well as macro-molecular, thermo-labile factors capable of reducing the uptake of 57CoB12 bound to rat intrinsic factor by perfused rat intestinal segments (p less than 0.01 and p less than 0.01). Neither non-radioactive vitamin B12 nor non-pacreatic protein reduced the 57CoB12-uptake (p greater than 0.5 and p greater than 0.1) Crystalline trypsin and trypsinogen, but not chymotrypsin, also inhibited the uptake (p less than 0.05, p less than 0.02 and p greater than 0.05). The tryptic inhibition was abolished by soybean trypsin inhibitor (p greater than 0.05).

The rates of electron transport and of ATP synthesis have been measured in bovine heart Mg-ATP submitochondrial particles oxidising succinate under conditions of partial attenuation of the proton-motive force by malonate or FCCP. This paper reports evidence that the relationship between the rate of ATP synthesis and the magnitude of the proton motive force is independent of the mode by which the decrease of the proton motive force is achieved.

Fifty-three patients with a suspected first anterior wall acute myocardial infarction (AMI) were randomized to intervention with intravenous heparin followed by oral warfarin (26 patients) or matching placebo (27 patients). The regimen was started within 12 hours after the onset of AMI. Anticoagulation was maintained at a therapeutic level (for heparin, activated partial thromboplastin time 70 to 140 seconds; for warfarin, thrombotest 5 to 10%) for 10 days, and no bleeding episodes occurred. The baseline characteristics of the 2 study groups were well matched. In 7 patients in the placebo group and in none in the anticoagulant group, left ventricular thrombus developed during the study, as detected by serial 2-dimensional echocardiography. Early intervention with high-dose anticoagulant drugs may prevent the development of left ventricular thrombus in anterior wall AMI.

Respiring submitochondrial particles from which the F1 sector of ATP-synthase was displaced generated a membrane potential in the range of 115-140 mV. Addition of oligomycin raised the membrane potential by approximately 40 mV. The lower membrane potential in particles with F1 displaced is attributed to partial dissipation of the proton electrochemical gradient as a consequence of proton flow through the open proton channels provided by the F0 sectors of the ATP-synthase. The characteristics of proton flow through the open F0 channels were studied by varying the rate of electron transport-driven proton translocation which permitted the establishment of a range of steady-state membrane potentials. Open F0 channels appeared to have a gated response to the membrane potential such that they were inoperative when the potential fell below approximately 110 mV. The membrane potential was measured as a function of respiratory rate in intact Mg-ATP submitochondrial particles that had been treated with low concentrations of the protonophore carbonylcyanide-p-trifluoromethoxyphenylhydrazone. In general a linear dependence of membrane potential upon respiratory rate was observed except at the lowest concentrations of protonophore and highest respiratory rates, presumably because the effect of the protonophore was then offset by an increased rate of proton translocation driven by the respiratory chain. The effect of increasing concentrations of carbonylcyanide-p-trifluoromethoxyphenylhydrazone on the membrane potential of respiring submitochondrial particles was studied. It was found that equal amounts of the protonophore lowered the membrane potential to a lesser extent at lower values of the membrane potential. Treatment of Mg-ATP submitochondrial particles with oligomycin slightly increased (by approximately 10 mV) the size of the respiration-dependent membrane potential, but did not alter the profile of membrane potential as a function of succinate oxidation rate. The latter was controlled by titration with malonate. This result indicates that the F0 sector of the ATP-synthase does not significantly contribute to leak pathways in intact submitochondrial particles.

(1) The effects of membrane potential (delta psi) and nucleotides on the interaction between the F1-ATP synthase and its natural inhibitor protein (IF1) are studied in ox-heart submitochondrial vesicles. (2) Membrane potential causes displacement of IF1 from submitochondrial vesicles, as shown by measuring both delta psi-dependent stimulation of ATPase capacity and release of 125I-labelled IF1 from the vesicles. These effects are abolished if ATP is included in the incubation. (3) There is a linear increase in the steady-state ATPase capacity of oxidising vesicles as delta psi is increased from 100 mV to 135 mV. Increasing delta psi above 140 mV leads to no further change. (4) At a constant membrane potential, ATP suppresses the increase in ATPase capacity, with a concentration for half maximal effect of 140 microM. This value is close to the Km for ATP hydrolysis by membrane-bound F1. This suppression is related to ATP concentration rather than to delta Gp or ATP/ADP ratio. (5) The unidirectional on- and off-rates of IF1 were measured separately. The off-rate of IF1 is increased by membrane potential but unaffected by ATP. The on-rate, conversely, is increased by ATP. Thus, the suppression of the potential-dependent net release of IF1 from submitochondrial vesicles by ATP results from an increase of the IF1 on-rate above the off-rate.

In a prospective study, 20 patients with a first acute myocardial infarction and no current treatment with diuretics or cardioactive drugs were randomized to treatment with intravenous timolol (10 patients) or placebo (10 patients). Plasma adrenaline, noradrenaline, and serum potassium were estimated at baseline (mean +/- SD 3.6 +/- 0.8 hours after the onset of the infarction) and 4 hours after the start of treatment. The patient selection criteria embraced a low-risk study population. Before treatment, the serum potassium concentrations correlated inversely with plasma adrenaline but not with plasma noradrenaline concentrations. A rise of serum potassium (mean +/- SD mmol/L) from 4.1 +/- 0.3 to 4.4 +/- 0.4 (p less than 0.05) in the placebo group and from 4.0 +/- 0.4 to 4.5 +/- 0.5 (p less than 0.05) in the timolol group was in multivariate analysis associated with infarct size, estimated as cumulative creatine kinase release, in the placebo group, and with the mean individual plasma adrenaline concentrations in the timolol group. By reversing the effect of adrenaline from a decrease to an increase in the serum potassium concentrations, timolol changes the relationships between circulating adrenaline, potassium, and infarct size.

Determination of vitamin-B12-binding capacity and gel filtration of human pancreatic juice (HPJ) and rat pancreatic juice (RPJ) demonstrated a vitamin B12 binder different from gastric intrinsic factor (IF). The results also indicated the presence of the pancreatic B12 binding in human duodenal juice. The binder in RPJ had no significant effect on the uptake of 57CoB12 and 57CoB12 bound to rat IF by perfused rat intestinal segments (p greater than 0.5; p greater than 0.1). The binder in HPJ had no effect on the uptake of unbound 57CoB12 or 57CoB12 bound to human IF by guinea pig intestinal brush borders (p greater than 0.05; p greater than 0.1). The results indicate that the pancreatic vitamin B12 binder does not influence the intestinal uptake of vitamin B12.

Resistance to the metabolic effects of insulin has been reported with regard to glucose disposal in type I diabetic patients (IDDM) even when they were euglycemic. Our aim was to study glucose, lipid, and amino acid metabolism during glucose clamping at multiple levels of insulin in 10 normal (N) and 6 IDDM patients. Blood glucose was maintained constant (4.7 mmol/liter) at three insulin plateaus (160 min each) [42 +/- 6 (SD) 89 +/- 11, and 1255 +/- 185 microU/ml in N and 36 +/- 4, 80 +/- 13, and 1249 +/- 107 microU/liter in IDDM]. Mean glucose disposal was 34 +/- 11, 69 +/- 10, and 84 +/- 22 mumol kg-1 min-1 in N and 16 +/- 5, 40 +/- 18, and 65 +/- 27 in IDDM, respectively. Baseline concentrations of blood lactate, pyruvate, alanine, and branched chain amino acids were 560 +/- 130, 36 +/- 9, 212 +/- 44, and 451 +/- 19 mumol/liter, in N and 793 +/- 179 (P less than 0.05), 45 +/- 14, 195 +/- 50, and 439 +/- 33 in IDDM, respectively. The maximum percent change of lactate during the euglycemic clamp was +147 +/- 23% in N and +75 +/- 15% (P less than 0.05) in IDDM; that of branched chain amino acids was -61 +/- 5% in N and -48 +/- 7% (P less than 0.01) in IDDM. Baseline concentrations of glycerol, FFA, and adipate were 44 +/- 15, 449 +/- 152, and 8 - 8 mumol/liter in N and 39 +/- 14, 473 +/- 44, and 41 +/- 14 (P less than 0.01) in IDDM. The maximum percent change of glycerol during the euglycemic clamp was -50 +/- 8% in N and -16 +/- 8% (P less than 0.01) in IDDM, that of FFA -98 +/- 3% in N and -70 +/- 4% in IDDM (P less than 0.05). No significant differences were found between N and IDDM with regard to blood concentrations of ketone bodies, citrate, ketoglutarate, and hydroxymethylglutaryl coenzyme A both before and during the euglycemic clamp. The lactate percent increase was significantly correlated to glucose disposal rate (P less than 0.001). The lactate turnover rate increased during the euglycemic clamp and was lower in IDDM than in N. We conclude that during euglycemic-multiple insulin clamp studies the greater lactate increase suggests that the flux of glycolysis is higher in N than in IDDM, tricarboxylic acid concentrations are comparable in N and IDDM, and FFA, glycerol, and branched chain amino acid decreases were less in IDDM than in N, suggesting that IDDM patients are resistant to insulin with regard to lipid and protein metabolism. The higher adipate basal values demonstrate enhanced omega-oxidation in IDDM.

The activity of the microsomal 3-hydroxy-3-methylglutaryl-coenzyme A reductase was assayed with a procedure based on the extraction of the product mevalonolactone in a benzene phase. Diamide is an uncompetitive inhibitor of the reaction, while coenzyme A disulfide and tetraethylthiouram disulfide act as non-competitive inhibitors. Diamide inhibition cooperatively increases with the inhibitor concentration. HMG produces a decrease in enzyme activity that combines with that of coenzyme A disulfide. Both CoASH and coenzyme A esters strongly inhibit the reductase activity. Three new synthetic compounds with either thio-ether or thio-ester groups also show inhibitory effect on the enzyme activity.

(1) The kinetics of the release of the mitochondrial inhibitor protein (IF1) is studied in bovine heart submitochondrial vesicles supplemented with 125I-labelled IF1, using a method for rapidly 'freezing' the state of F1-IF1 interaction. It is shown that generation of a protonmotive force leads to release of IF1 from F1 into solution, following an exponential process. (2) In one set of experiments the rate of IF1 release, in IF1 supplemented vesicles generating a protonmotive force, is correlated with the induction of ATP hydrolytic capacity. It is found that, even under different metabolic states (phosphorylating and non-phosphorylating conditions), both processes follow the same time-course (half-time of around 40 s) and that there is a direct correlation between induced ATPase capacity and IF1 released. This finding rules out the possibility of a non-inhibitory binding site for IF1 on the membrane. (3) In a second set of experiments, also using IF1 supplemented vesicles, the induction of the ATP hydrolytic capacity after energisation is correlated with the induction of the ATP synthetic capacity. Initial rates of both processes are monitored using firefly luciferase, keeping the assay systems as similar as possible. It is shown that the induction of each capacity follows an exponential time-course, with a half-time of around 40 s. This is in good agreement with the half-times obtained for the induction of ATP hydrolytic capacity and the rate of IF1 release, using the quench-stop method. (4) If the induction of ATP hydrolytic and synthetic capacities is followed in untreated submitochondrial vesicles, i.e., vesicles not supplemented with IF1, the extent and time-course of the change in both hydrolytic and synthetic capacities remain correlated, but the half-time of the transient falls to around 10 s. It is suggested that the length of the transient, observed in IF1 supplemented vesicles, results from partial loss of coupling during repeated centrifugations. (5) These results demonstrate that energy-dependent release of IF1 from F1 into solution results in a concomitant increase in both ATP synthetic and hydrolytic capacities of the ATP synthase complex, and that the time-course of this process is sensitive to the degree of coupling of the vesicles.

A method for the measurement of organic acids in human plasma is presented. The analytical procedure consists of plasma protein precipitation with acetonitrile, acid extraction by chromatography through a DEAE-cellulose column eluted with 100 mM perchloric acid, HPLC by cation-exchange column Aminex HPX-87 eluted with 6.5 mM sulfuric acid. Adipic, 3-hydroxy-3-methylglutaric, 2-oxoglutaric, and citric acids were determined in the plasma of diabetic patients. The concentrations of all the measured acids, but particularly those of adipic and 3-hydroxy-3-methylglutaric acids, were significantly higher than those of healthy controls. These results suggest that in diabetics the omega-oxidation of fatty acids is enhanced.

Total ketone bodies and 3-hydroxy-3-methylglutaric acid (HMG) were determined in urines of full-term and pre-term newborns from the first day after birth to an age of 17. Significantly higher levels of the two catabolites were observed in the first two weeks of life of the pre-term newborns. A peak of excretion of both ketone bodies and HMG was found between the 7th and the 10th day after birth in both groups of newborns. After the 3rd month there is no significant difference between full-term and pre-term children as far as the excretion of the two analytes is concerned.

Pancreatic extract (PE) reduced the uptake of rat intrinsic factor (IF)-bound 57CoB12 by perfused rat intestinal segments (p is less than 0.02) as well as by isolated rat intestinal brush borders (p is less than 0.01). The inhibition was concentration-dependent. Preincubation of the brush borders with PE recular weight of the 57CoB12-IF complex, as well as the uptake of the complex by isolated intestinal brush borders, was unchanged after prolonged preincubation with PE. PE also inhibited the uptake of glucose by perfused intestinal segments (p is less than 0.01), but the morphology and idsaccharidase activity (p is greater than 0.5) of the intestinaleptihelium was unaltered. The results indicate that the inhibition may be due to interaction between the intestinal epithelium and PE.

The mean absorption of vitamin B12 (Schilling test) was 13.1 +/- 1.0 (% +/- S.E.M.) in 21 patients with chronic pancreatic insufficiency and 17.6 +/- 1.4 in 13 control patients (p less than 0.01). There was no correlation between pancreatic bicarbonate production after secretion stimulation and vitamin B12 absorption in the patient group (r = 0.117). Human duodenal juice reduced the uptake of 57CoB12-rat intrinsic factor (IF) by perfused rat small intestinal segments in vivo (p less than 0.01) as well as the uptake of 57CoB12-human IF by purified guinea-pig intestinal brush borders in vitro (p less than 0.01). The results confirm reduced absorption of vitamin B12 in chronic pancreatic insufficiency, but the mechanism remains uncertain.

This is a subproject of the Norwegian timolol myocardial infarction study carried out at one of the clinical centers. High risk patients surviving either a reinfarction or large initial infarction were randomized to placebo (44 pts) or timolol (37 pts). A 24 hour ECG was obtained the day before randomization (at baseline, 7-28 days after the acute attack) then 3 days, 1 month and 6 months after start of therapy. During this period the number of patients with one or more of ventricular couplets, bigemini, ventricular tachycardia or early cycle premature ventricular contractions (PVC) (i.e. complex ventricular arrhythmias) and the average number of PVC per hour increased significantly in the placebo group but not in the timolol group. The results indicate that there is an increased severity and incidence of ventricular arrhythmias in the first 6 months after myocardial infarction. Timolol effectively inhibited this trend. The importance of timolol as an antiarrhythmic agent may therefore be to prevent subclinical infarction extension and secondary ventricular arrhythmias related to the size of the myocardial damage.

The effect of prazosin in congestive heart failure was assessed in 10 patients (age 39--69) years) with ischemic heart disease or cardiomyopathy in functional class II-IV (NYHA). All patients were treated with digitalis and diuretics in optimal doses. Mean (+/- S.E.M.) cardiac index (CI) was 2.2 +/- 0.2 l/min/m2 before and 2.3 +/- 0.1 one hour after oral administration of 2--4 mg prazosin (given as tablets) (p less than 0.10). Mean pulmonary capillary wedge pressure (PWP) fell from 24 +/- 4 to 20 +/- 4 mmHg (p greater than 0.10). Prazosin seemed to have a more beneficial effect on patients with markedly elevated PWP or reduced CI before prazosin administration. The effect of prazosin on heart rate and systolic blood pressure was insignificant. During a follow-up period of 1--20 months (mean 7.3), 2 of 7 patients treated with prazosin (2--4 mg daily) improved their clinical condition, one patient was unchanged and 4 patients died in progressive cardiac failure. The results indicate that some patients with severe heart failure may benefit from prazosin when conventional treatment has failed.

Urinary levels of 3-hydroxy-3-methylglutaric acid (HMG) were measured by gas-liquid chromatography (GLC) after an extraction with tetrahydrofuran in normal rats, streptozotocin-diabetic rats and starved rats. The analysis was also carried out in the urine of three diabetic patients after suspending the insulin treatment. Detectable amounts of HMG are excreted in urine by normal humans and rats and such an excretion increases in the diabetic condition. Starved rats present only traces of HMG in the urine.

To determine the mechanism by which pancreatic extract (PE) corrects the malabsorption of vitamin B12 in chronic pancreatic insufficiency (CPI), the following hypotheses were investigated: Firstly, PE might stimulate the absorption of vitamin B12 by changing the intestinal pH, secondly PE might stimulate the intestinal uptake of unbound vitamin B12, thirdly PE might abolish the inhibitory effect of vitamin B12 binders on the intestinal uptake of vitamin B12 bound to intrinsic factor (IF). PE had no effect on the pH in the small intestine and did not stimulate the uptake of unbound 57CoB12 by perfused rat intestinal segments. Preincubation of 57CoB12-IF with a non-IF B12-binder from human saliva (R-binder) reduced the uptake of 57CoB12 from 18.5 pg per cm intestine +/- 3.4 S.E.M. to 7.8 +/- 1.6 (p less than 0.02). PE abolished this inhibitory effect (p less than 0.05). The results indicate that PE corrects the malabsorption of vitamin B12 in CPI by an effect on non-IF B12- binders.