bluuebunny/crossref_metadata_2025 huggingface dataset:
The Eck Fistula Rat: Definition of an Experimental Model*,**
Authors: Herz R. , Sautter V. , Robert F. , Bircher J.
Published: March 2008

Abstract Fifty‐nine male Sprague‐Dawley rata were subjected to an end‐to‐side portacaval shunt and compared with appropriate controls. During the first ten days after the operation, the liver weights decreased from an average of 4.2 to 2.3% of the body weight and thereafter remained at this level. Testicular atrophy also occurred regularly but only after the tenth postoperative day. Three weeks after the operation, the body weight of shunted rats had decreased by an average of 20%, whereas sham operated controls gained 17%. These changes were related to food intake and coprophagy. Hyper‐ammonaemia developed gradually and levelled off at about 500 (μg/100 ml. Other alterations were more variable in severity. Spontaneous motor activity decreased to 12–77% of the preoperative value and was significantly correlated with changes in body weight. The electrocorticographic pattern was characterized by an average increase in rapid waves to 205% after five to six weeks, whereas the slow waves remained unchanged. These studies have established a standard of reference for further investigations with this animal model.
Mono‐ and Divalent Electrolyte Patterns, pCO2 and pH in Relation to Flow Rate in Normal Human Parotid Saliva*
Authors: Kreusser W. , Heidland A. , Hennemann H. , Wigand M. E. , Knauf H.
Published: March 2008

Abstract In parotid saliva of normal subjects the pH, pCO2 and concentrations of sodium, potassium, calcium, magnesium, bicarbonate and inorganic phosphate were determined continuously after stimulation of salivary secretion by pilocarpine. The electrolyte concentrations showed a marked dependence on salivary flow rate. Sodium, calcium and bicarbonate concentrations and pH increased with increasing flow rate but the concentrations of potassium, magnesium and inorganic phosphate decreased with increasing flow rate. In general salivary electrolyte concentrations showed a tendency to approach plasma concentrations with increasing flow rate with the exception of the salivary magnesium concentration, which fell below its plasma level and bicarbonate which exceeded the plasma concentration. The results will be considered as a basis of further investigations on electrolyte excretion patterns in patients with hormonal and metabolic disturbances.
Release of Immunoreactive Insulin from the Human Heart
Authors: Wahlqvist M. L. , Kaijser L. , Lassers B. W. , Löw H. , Carlson L. A.
Published: March 2008

Abstract Arterial‐coronary sinus differences in plasma immunoreaetive insulin concentration have been determined in 21 healthy men in the fasting state. Measurements were made both at rest and during prolonged exercise in all subjects and, in 9 of these, during an intravenous infusion of sodium nicotinate. Significant myocardial extraction of insulin could not be detected, but during prolonged exercise and also during the infusion of sodium nicotinate in resting subjects, net release of insulin from the myocardium took place. There was a positive linear relationship between arterial‐coronary sinus difference in insulin concentration and arterial insulin concentration. The most marked release of insulin from the heart occurred at the lowest arterial concentrations.
Cytochemical Population Analyses of Glycogen in Neutrophil Leukocytes of Chronic Myelocytic Leukaemia during Busulfan Treatment
Authors: Gahrton Gösta , Zetterberg Anders
Published: March 2008

Abstract A comparative investigation of glycogen content and glycogen synthesis in neutrophil leukocytes from patients with untreated chronic myelocytic leukaemia (CML) and CML in remission was undertaken using microspectrophotometry of the periodic acid‐Schiff (PAS) reaction and autoradiography after glucose‐H3 incorporation into glycogen of single cells. The glycogen content was low and the rate of glycogen synthesis high in neutrophils from untreated CML, indicating an increased glycogen turnover rate in these cells compared to normal neutrophils. Both glycogen content and rate of glycogen synthesis reached normal levels in CML neutrophils in busulfan induced remission. This normalization of glycogen metabolism was not observed until WBC approached normal values after several weeks of treatment. This indicates that the effect of busulfan on normalization acted at the level of the myeloid precursor cell. The mechanism of normalization may be due to busulfan partially or completely eradicating a cytochemically abnormal leukaemic cell population and thereby “unmasking” a cytochemically normal cell population.
Denervation Diuresis and Renin Secretion in the Anaesthetized Dog
Authors: Bencsáth P. , Szalay L. , Debreczeni L. A. , Vajda L. , Takács L. , Fischer A.
Published: March 2008

Abstract Simultaneous determinations of renal sodium excretion and renin secretion have been performed on 10 anaesthetized dogs, 1–2 weeks after unilateral splanchnicotomy (“renal denervation”). Under basal conditions, urine flow and sodium excretion were increased, renal venous renin activity (RVRA) and secretion decreased on the denervated side. During isotonic volume expansion a quantitative increase in denervation diuresis and natriuresis occurred while RVRA in denervated kidneys decreased further and the secretion rate became negative. Regardless of the absolute differences in water and sodium excretion between intact and denervated kidneys, RVRA and the output of the latter amounted to about 60 per cent of the intact kidney values. Both sodium reabsorption and renin production seem to be neurally regulated; their interrelationship is discussed.
Studies on Cholesterol Turnover in Normocholesterolaemic Subjects
Authors: Sandhofer F. , Bolzano K. , Sailer S. , Braunsteiner H.
Published: March 2008

Abstract. In 16 subjects with a plasma cholesterol concentration below 282 mg/100 ml, various parameters of cholesterol turnover were estimated from the specific activity time curve of plasma cholesterol after an intravenous injection of labelled cholesterol. The calculations were based on a two‐exchangeable‐pool model. The size of the more rapidly exchangeable pool A was inversely related to the fractional removal rate of cholesterol from this pool. The size of the more slowly exchangeable pool B was positively related to the amount of cholesterol which was transferred from pool A to pool B per unit of time. The concentration of plasma cholesterol, which forms part of the rapidly exchanging pool A, was not related to the size of pool A nor to the fractional removal rate from pool A, but was positively correlated with the production rate (synthesis plus absorption) of cholesterol.
Effect of Cold Pressure Test and 2‐deoxy‐d‐glucose Infusion on Plasma Renin Activity in Man*
Authors: Peytremann A. , Favre L. , Vallotton M. B.
Published: March 2008

Abstract. It has been reported that catecholamines stimulate plasma renin activity (PRA) in vivo and in vitro. Yet the respective roles of endogenous epinephrine and norepinephrine are still debated. Therefore two tests were performed in human subjects: the cold pressure and the 2‐deoxy‐d‐glucose tests. During these tests and on a control day, blood samples were taken at short intervals for PRA; in some subjects the excretion of epinephrine (E) and norepinephrine (NE) was also measured. In 9 healthy males the cold pressure test induced an immediate NE response with increase of systolic and diastolic blood pressure without change in the blood glucose concentration. There was no significant change in the mean value of PRA although in four subjects some rise of PRA occurred. The 2‐deoxy‐d‐glucose induced, in response to an intracellular glucopaenia, an E discharge with a rise in the blood glucose concentration. In all 8 healthy males a striking rise of PRA was observed. Neither hyperglycaemia nor the concomitant decline of serum potassium could explain this rise of PRA, since the same changes during oral glucose test were not accompanied by a similar elevation. Patients with Addison's disease of tuberculous origin responded in a normal fashion to the cold pressure test, but failed to present a hyperglycaemia and a rise of PRA in response to 2‐deoxy‐d‐glucose. This indicates that an intact adrenal medulla was required for the last stimulus but not for the former. From these studies in man it would appear that endogenous epinephrine stimulates renin more strongly than norepinephrine.
Further Evaluation of the Role of Insulin in Sodium Retention Associated with Carbohydrate Administration after a Fast in the Obese*
Authors: Kolanowski J. , de Gasparo M. , Desmecht P. , Crabbé J.
Published: March 2008

Abstract. This study was aimed at elucidating the role which insulin was thought to play in the mechanism(s) underlying sodium retention associated with glucose intake after a week of total fast in the obese. Parenteral (I.V.) and oral (p.o.) administration of glucose proved equally effective in this respect, thereby ruling out a significant influence of enteric factor(s) involved in the metabolic response to glucose ingestion. Furthermore, the data indicated that the amplitude of the β‐cell secretory response was not critical for sodium retention, as it was much smaller when glucose was given I.V. rather than p.o. Attempts at raising blood glucose concentrations and insulin concentrations independently (by infusing epinephrine vs. insulin) after a few days of fasting, proved fruitless as neither situation was associated with sodium retention. Thus, variations in insulin concentrations appear to be insufficient to account for the changes in salt and water balance associated with starvation and carbohydrate refeeding. Glucagon, known to be natriuretic and to be secreted in increased amounts during starvation and insulin‐induced hypoglycaemia, was thought to be the additional factor to be considered. Indeed, injection of glucagon blocked the sodium retention usually observed upon glucose administration after a short fast.
The Use of Leucocytes as an Aid in the Diagnosis of a Variant of Glycogen Storage Disease Type II (Pompe's Disease)
Authors: Koster J. F. , Slee R. G. , Hülsmann W. C.
Published: March 2008

Abstract. By determining the ratio of the acid‐ and neutral maltase activities of leucocytes it is possible to detect muscle acid maltase deficiency (Variant of glycogen storage disease Type II). It is not possible to detect the heterozygotes with this ratio. However, this can be done by analyzing the kinetics of the inhibition by turanose of the acid maltase in the leucocytes. Electrophoresis of leucocyte homogenates shows separation of two distinct bands from the starting position in controls but only one band in patients.
The Prognostic Value of Right Atrium Monophasic Action Potential after Conversion of Atrial Fibrillation
Authors: Cotoi Simion , Gavrilescu Stefan , Pop Tiberiu , Vicas Elisabeta
Published: March 2008

Abstract. After conversion of atrial fibrillation right atrium monophasic action potentials have been recorded in 45 patients, using a bedside suction technique. In 30 patients who reached sinus rhythm after DC shock, a good correlation was, found between the duration of monophasic action potential and the sinus rhythm stability during a follow‐up period of six months. In 8 patients still in sinus rhythm after six months and in 15 patients who reached sinus rhythm spontaneously, the duration of monophasic action potential was in the normal range. In 22 patients who relapsed into atrial fibrillation during the follow‐up period, the maintenance of sinus rhythm was closely related with the duration of the monophasic action potential, which was shorter than in stable sinus rhythm. The duration of monophasic action potential after conversion of atrial fibrillation has a prognostic value for the maintenance of sinus rhythm, and when its duration is short a conservative treatment instead of repeated DC shocks may be considered.
Effect of Altitude on Erythropoiesis and Oxygen Affinity in Anaemic Patients on Maintenance Dialysis
Authors: Blumberg A. , Keller H. , Marti H.R.
Published: March 2008

Abstract. Six anaemic patients with terminal renal failure on maintenance haemodialysis and three healthy control subjects were exposed to altitude hypoxia at Jungfraujoch (3450 m above sea‐level). In normal subjects plasma erythropoietin (ESF) as determined by the exhypoxie mouse assay exhibited the expected rise after 24 h (from 0.25 to 3.09%6*Fe incorporation). In the patients a smaller but still significant rise was demonstrable (from 0.39 to 2.18%MFe incorporation), indicating that even severely damaged kidneys with negligible exocrine function retain a definite endocrine reserve for ESF production. For this reason bilateral nephrectomy should be avoided in these patients if possible. 2,3‐DPG and P50 (as corrected to pH 7.4) as well as blood pH increased within 24 h after altitude exposure in the control subjects, as described previously. In the patients the two parameters were already elevated under baseline conditions. Upon hypoxic stimulation they rose further (from 44.7 to 56.5 (junoles/1011 Ec. and from 28.6 to 30.1 mmHg respectively), while a definite fall in whole blood pH occurred. High altitude exposure was tolerated remarkably well by the dialyzed patients in spite of the presence of anaemia and severe renal failure.
Effect of Insulin Induced Hypoglycemia on Thyroid Function and Thyroxine Turnover*
Authors: Blum C. , Cornette C. , Beckers C.
Published: March 2008

Abstract. The effect of long‐term hypoglycemia induced by insulin on thyroid metabolism has been investigated in 13 normal subjects. No modification of the uptake or release of radioactive iodine by the thyroid has been observed. A significant increase of circulating thyroxine was found for as long as 8 h after insulin injection. Turnover studies with radioactive thyroxine indicate that during the period of insulin administration, there is a slower disappearance rate of labelled thyroxine from the plasma which occurs simultaneously with a significant drop of the hepatic radioactivity. It seems likely that the enhanced concentration of serum thyroxine is related to the release of thyroxine molecules stored in the liver.
Positive Correlation of Serum Lecithin: Cholesterol Acyltransferase Activity with Relative Body Weight
Authors: Akanuma Y. , Kuzuya T. , Hayashi M. , Ide T. , Kuzuya N.
Published: March 2008

Abstract. The activity of serum lecithin:cholesterol acyltransferase (LCAT) was measured in 33 subjects who had no apparent diseases except obesity in some cases. Their liver function tests were all within normal limits. The correlations of serum LCAT activity with sex, age, glucose tolerance, relative body weight, basal immunoreactive insulin, and fasting serum cholesterol and triglyceride were studied. – The results indicate that an increase in serum LCAT activity is significantly correlated with increases in relative body weight, serum total cholesterol, serum unesterified cholesterol, serum basal immunoreactive insulin, and serum triglyceride. – At present the physiological significance of serum cholesterol es‐terification is not fully established. However, the present findings suggest an increased turnover of serum esterified cholesterol in obese subjects.
Secretion of Thyroxine and Non‐Thyroxine Iodine by the Normal Human Thyroid Gland. Influence of Carbimazole and Pharmacological Doses of Iodide
Authors: Bürgi H. , Andersen M. C. , Schwander J. , Kohler H. , Stude H.
Published: March 2008

Abstract. In order to measure the effect of antithyroid agents on thyroxine and non‐thyroxine iodine secretion by the normal human thyroid gland, 12 normal persons were given tracer amounts of iodide‐125I. 7 to 11 days later thyroxine‐131I was injected I.V. Two days later the following serial measurements were started: Serum protein‐bound labeled iodine (PB125 PB131I), serum total thyroxine, and excretion of 125I and 131I in urine.–In the control period (no drugs) the secretion rate for thyroxine was 83 μg/day. Carbimazole (15 mg three times daily) for 6 days did not affect thyroxine secretion despite a complete block of iodine uptake by the thyroid. Non‐thyroxine iodine secretion was 59 μg/day in the control period and rose to 183 μg under carbimazole.–Non‐thyroxine iodine includes triiodothyronine and any non‐hormonal iodine, such as iodide derived from the deiodination of iodotyrosines, secreted by the gland. Based on recently published estimates it was assumed that the triiodothyronine contribution was not more than 24 μg. This left a considerable efflux of non‐hormonal iodine even in the control period. Most of the non‐hormonal iodine produced, however, was recycled into thyroglobulin without leaving the gland. After blocking reutilization by carbimazole large amounts of non‐hormonal iodine were secreted by the gland. High doses of iodide (30 mg three times daily) in combination with carbimazole led to a rapid 45% decline in thyroxine secretion. Since a complete block of hormone synthesis by carbimazole alone had no such effect, high iodide doses must act at a different site, presumably by slowing down the release of hormone from preformed thyroglobulin stores. The findings indicate that carbimazole enhances the sensitivity of the normal thyroid gland toward pharmacological doses of iodide.–High doses of iodide together with carbimazole reduced the secretion of non‐hormonal iodine (which can be taken as an index of thyroglobulin hydrolysis) by only 31%. Moreover some subjects showed no reduction at all, despite of concomitant fall in hormone secretion. The lack of correlation between the decreases of thyroxine and of non‐hormonal iodine secretion does not support the generally held view that high doses of iodide block hormone release by interfering with the hydrolysis of thyroglobulin.
The Acute Parathyroid Hormone Response to Changes in Ionized Calcium during Phosphate Infusions in the Cow
Authors: Fischer Jan A. , Binswanger Ulrich , Blum Jürg W.
Published: March 2008

Abstract. The concentration of plasma immunoreactive parathyroid hormone ([IPTH]) increased within one minute after the plasma ionized calcium concentration ([Ca++]) had been lowered by phosphate infusions in 8 cows. The decrease in [Ca++] could be accounted for by a rise in nonultrafiltrable calcium. The plasma total calcium concentration ([CaTot]) remained unchanged during the first 4 minutes of the phosphate infusion. Until this time [IPTH] was inversely related to [Ca++] and directly related to plasma phosphorus concentrations, but not to [CaTot]. Peak levels of [IPTH] were attained at 4 minutes, before the nadir of [Ca++] was reached and prior to a significant fall in [CaTot]. The data suggest that initial decreases in ionized but not in total calcium stimulate parathyroid hormone secretion. They provide evidence for a model of parathyroid hormone secretion which includes a small storage pool available for immediate release in response to a lowering of the [Ca++]. Between 4 and 12 minutes [IPTH] remained approximately constant in association with a continued fall in [Ca^], whereas between 13 and 16 minutes (the end of the phosphate infusions) [IPTH] was decreasing in association with still falling [Ca++]. It can be speculated that the synthesis of PTH is insufficient to account for a sustained increase in [IPTH], or that abrupt decreases of [Ca++] inside the parathyroid cells inhibit the secretion coupling mechanisms. Finally after 16 minutes [IPTH] continued decreasing in relation to the rising [Ca++].
Simultaneous Quantitative Measurement of 131I‐Iodine and 99mTc‐Pertechnetate Uptake by Human Salivary Glands Using Scintiscanning with Validation by Direct Estimation in Biopsy Samples
Authors: Lazarus J. H. , Stephen K. W. , Harden R. McG. , Robertson J. W. K. , Lister G.
Published: March 2008

Abstract.
131I‐iodide and 99Tc‐pertechnetate concentration in human salivary glands has been measured simultaneously in vivo by quantitative scintiscanning in 7 thyrotoxic subjects. The mid scan times were 5, 12 and 20 min. and the gland to plasma ratio (G/P) of 131I rose to 4.03±0.82 (s.e.) in the parotid and 10.7 ±3.1 (s.e.) in the submandibular glands. Corresponding values for G/P 99mTcO4‐were 2.70 ±0.34 in the parotid and 5.3 ± 1.2 in the submandibular glands. Values obtained at parotidectomy 1 h after intravenous administration of a mixture containing 125I‐ and 99mTcO4‐ to 6 patients were 4.13 ± 0.85 for G/P 125I‐ and 2.50 ± 0.62 for G/P99mTcO4‐. G/P131I‐ (or G/P125I‐) and G/P 99mTeO4‐, derived by both methods, were significantly correlated in parotid and submandibular glands. There was a significant correlation between G/P 131I‐/G/P 99mTcO4‐ in the parotid glands and G/P131I‐/G/P99mTcO4‐ in the submandibular glands. ‐It is concluded that 1. salivary gland values of 131I‐ and 99mTcO4,‐as measured by scintiscanning are very close to values obtained by direct counting of excised human salivary gland tissue and 2. that the secretion processes in both glands are physiologically related.
The Effect of the β‐Receptor Blockade (Propranolol) on the Endocrine and Exocrine Pancreatic Function in Man after the Administration of Intestinal Hormones (Secretin and Cholecystokinin‐Pancreozymin)
Authors: Raptis S. , Dollinger H. , Chrissiku M. , Rothenbuchner G. , Pfeiffer E. F.
Published: March 2008

Abstract. The effect of propranolol on the induction of endocrine and exocrine pancreatic function by secretin (SC) and cholecystokinin‐pancreozymin (CCK/PZ) was investigated in 35 metabolically normal subjects. Insulin secretion could be inhibited by propranolol after administration of glucose or SC. On the other hand it was not possible to inhibit the CCK/ P2 induced insulin secretion by propranolol. Exocrine pancreatic function was not influenced by the administration of propranolol. Our results suggest that the action of SC on the islet system, like that of glucose, is linked to the β‐adrenergic system.
Metabolic Activity in Rat Skeletal Muscle:Effect of Intermittent Hypoxia
Authors: Holm J. , Bjorntorp P. , Schersten T.
Published: March 2008

Abstract. In order to determine whether hypoxia is a trigger for changed metabolic activity in muscle tissue, rats were exposed to intermittent hypoxia of varying degree (5% 02, 8% 02, 10% 02, 12% 02, 15% 02 in N2) 3 h per day for 1–4 weeks. The effects of hypoxia on the rate of incorporation of glucose‐carbon into glycogen, lipids, carbon dioxide and lactate and on succinic oxidase activity in skeletal muscle tissue were determined. Rats intermittently exposed to 5% oxygen in nitrogen for one week showed a significant decrease of the rate of incorporation of glucose‐carbon into lipids and carbon dioxide and a significant decrease in succinic oxidase activity. In rats exposed to 8 and 10% 02 a significant increase of the incorporation rate of glucose‐carbon into glycogen, lipids and carbon dioxide was found after 1 and 4 weeks and succinic oxidase activity increased after 4 weeks. The phospholipid concentration in muscle tissue decreased after 8 and 10% 02 exposure for 4 weeks. In the rats exposed to 8% oxygen for 4 weeks the protein concentration of muscle tissue increased significantly.–Based on these results it is suggested that the change of the glycolytic activity and succinic oxidase activity in muscle tissue after physical training and in arterial insufficiency are induced by hypoxia in the muscles.
The Relationship between Plasma Catecholamine Concentration and Pulse Rate during Exercise and Standing
Authors: Christensen Niels Juel , Brandsborg Ole
Published: March 2008

Abstract. Plasma catecholamine concentrations (PCA) were measured during standing and exercise using a precise and sensitive double‐isotope derivative technique. By plotting the increase in PCA in the standing position on the y‐axis of a coordinate system against the increase in pulse rate, PCA was resolved into two components: one corresponding to the intercept of the y‐axis where rise in pulse rate equals zero (CAP) while the other (CAH) was calculated by multiplying the slope of the regression line by the mean increase in pulse rate.–The rise in PCA, mainly noradrenaline, was considerably less during light to moderate exercise than during standing. Thus there was no rise in PCA during exercise until the increase in pulse rate exceeded approximately 30 beats/min and there was no rise in the CAP component during exercise. When PCA began to rise during exercise the increase in PCA per increment in pulse rate was similar to that observed in the standing experiments. There was no difference between the increments in PCA observed during exercise in the supine and the sitting positions but resting PCA was doubled in the sitting position.–It is suggested that 1. the initial rise in pulse rate during exercise is due to withdrawal of parasympathetic activity on the heart 2. the increase adrenergic in vasoconstrictor activity is considerably less during moderate exercise than during standing 3. the increase in plasma noradrenaline during moderate exercise is of cardiac origin.
Effect of Volume Expansion by Hyperosmolar and Hyperoncotic Solutions under Constant Infusion of Angiotensin II on Plasma Aldosterone in Man and its Counterbalance by Potassium Administration
Authors: Birkhäuser M. , Gaillard R. , Riondel A. M. , Scholer D. , Vallotton M. B. , Muller A. F.
Published: March 2008

Abstract. The influence on plasma aldosterone of plasma volume expansion by hyperosmolar and hyperoncotic solutions and its counterbalance by potassium administration was studied in man. All experiments were done during constant infusion of angiotensin II (All) which consequently excluded changes of the endogenous renin. Hyperosmolar infusion of NaCl, mannitol and NaHCO3 provoked an immediate fall in plasma aldosterone levels and presumably a shift of intracellular potassium to the extracellular compartment. Hyperoncotic solutions of dextran in 0.9% NaCl provoked an immediate fall in plasma aldosterone while dextran in 5% glucose provoked a delayed fall. Administration of minute amounts of potassium could prevent the fall in plasma aldosterone which followed administration of dextran solutions. The same minute amount of potassium, administered without volume expansion, increased plasma aldosterone markedly above the high levels induced by AII. – The data presented add further evidence for the important role of potassium as a mediator in aldosterone regulation. They indicate that intracellular potassium changes at the adrenal level, rather than plasma potassium concentration, probably exert the regulatory function in aldosterone biosynthesis.
Praecordial Accelerometry: An Indirect Assessment of Left Ventricular Performance
Authors: Reuben S.R. , Littler W.A.
Published: March 2008

Abstract. 1. Praecordial acceleration was measured by a “pixie” strain gauge transducer in 14 dogs in whom an electromagnetic flow probe and pacing electrodes had been implanted. Peak acceleration of blood from the left ventricle (aortic max. dv/dt) was derived from the flow signal by differentiation. – 2. The amplitude of the major systolic complex (DE) of the praecordial accelerogram and aortic max. dv/dt were measured during stimulation of the heart with calcium gluconate and isoprenaline and depression of the heart with propranolol and halothane inhalation. – 3. Close linear correlations were found between the percentage change in the DE complex and the percentage change in aortic max. dv/dt during stimulation and depression of the heart. – 4. The amplitude of the DE complex was found to be sensitive to changes in left ventricular end‐diastolic pressure, systemic vascular resistance and increase in heart rate up to 150 beats per minute. – 5. It is concluded that changes in the amplitude of the DE complex of the praecordial accelerogram may be a useful index for non‐invasive assessment of changes in left ventricular function in the dog.
Metabolism of the Vitamin A Transporting Protein Complex
Authors: Vahlquist A. , Peterson P. A. , Wibell L.
Published: March 2008

Abstract. Biological turnover studies of the human vitamin A transporting protein complex and its individual components, prealbumin and retinol binding protein (RBP) have been performed in normal persons and in patients with severely impaired kidney function. The metabolic behaviour of prealbumin was very similar in the two groups of subjects studied, and it was concluded that prealbumin eatabolism can be dependent to only a minor extent on normally functioning kidney glomeruli.–RBP is present in several molecular forms in plasma. In normal conditions virtually all PRB is bound to prealbumin, but small amounts of RBP also occur in free form. The concentration of the free RBP is greatly increased in patients with grossly impaired glomerular filtration. The biological half‐life for free RBP was short in normal persons (about 4 hours) whereas in the patients this parameter was increased 10 to 15 fold. These findings suggest that most if not all free RBP in plasma is catabolized by the kidney. RBP complexed with prealbumin has a considerably longer half‐life than its free counterpart in normal persons but the absolute synthetic rate of the two components of RBP is similar. Thus it is proposed that most RBP is catabolized from the pool of the uneomplexed species.–From the data it can be calculated that as much as one third of the plasma vitamin A may be deposited in the kidney tubuli on degradation of RBP, since the mechanism for the renal eatabolism of this small protein seems to involve glomerular filtration followed by tubular reabsorption.
Failure of Phenobarbital and Marijuana to Stimulate the Smooth Endoplasmic Reticulum in the Human Intestinal Absorptive Cell
Authors: Tytgat G. N. , Saunders D. R. , Rubin C. E.
Published: March 2008

Abstract. Administration of phenobarbital or marijuana to healthy volunteers did not induce changes in the small intestinal microsomal fraction, as estimated by electron microscopy and by protein quantification. These results are in contrast to the susceptibility of the hepatocyte to smooth endoplasmic reticulum induction by phenobarbital.
Renal and Cardiovascular Effect of Prostaglandin A2 in Hypertensive Patients
Authors: Hornych Antonin , Safar Michel , Papanicolaou Nicolas , Meyer Philippe , Milliezy Paul
Published: March 2008

Abstract. The haemodynamic and renal effects of synthetic prostaglandin A2 (PGA2) have been studied in 10 hypertensive subjects during a) a short lasting infusion of hypotensive doses of 3–9μg/kg min. of PGA2; b) a continuous infusion starting with subdepressive doses and extended with hypotensive doses.—The rapid hypotensive effect observed with high doses was accompanied by an increase in cardiac output and renal blood flow without significant changes in the peripheral vascular bed. Hepatic blood flow was decreased. These observations show a preferential renal redistribution of cardiac output. During the administration of subdepressive doses of PGA., a marked renal effect was observed, consisting in an increase in free water clearance and diuresis with no significant modifications of general haemodynamics. The natriuretic effect was much less pronounced suggesting that PGA2 is not a specific natriuretic hormone.—The haemodynamic and renal effects of endogenous PGs may play an important role in renal functions and in blood pressure regulation.
Plasma Cholesterol Esterification in Patients with Secondary Hypocholesterolaemia
Authors: Miller J. P. , Thompson G. R.
Published: March 2008

Abstract. Plasma lecithin cholesterol acyltranaf erase (LCAT) activity was found to be significantly reduced in patients with intestinal malabsorption. Despite this the proportion of esterified cholesterol in plasma was relatively normal. LCAT activity was correlated with the amount of cholesterol carried in high density lipoproteins (HDL) but not with whole plasma cholesterol. Plasma from the patients with malabsorption appeared to be as effective a substrate for a “standard” LCAT source as control plasma, and administration of Intralipid to replenish the reduced proportion of linoleic acid in plasma lecithin did not improve the efficacy of malabsorber plasma as an LCAT substrate. Treatment of patients with pernicious anaemia with vitamin B12 was followed by marked increases in plasma concentrations of free and ester cholesterol and also in plasma LCAT activity, but there was relatively little change in the proportion of the plasma cholesterol which was esterified.—The results are compatible with the hypothesis that the concentration of free cholesterol in plasma, or some related variable, is a determinant of circulating LCAT activity.
Enzymatic and Circulatory Adjustments to Physical Training in Middle‐Aged Men*
Authors: Bergman H. , Björntorp P. , Conradson T.‐B. , Fahlén M. , Stenberg J. , Vamauskas E.
Published: March 2008

Abstract. Eleven men aged 54–55 years and free of major cardiovascular abnormalitieswere trained on a bicycle ergometer for 25 minutes three times a week for six weeks. Estimated maximal oxygen uptake increased significantly by 18 per cent. Succinic oxidase activity in muscle tissue increased significantly from 21.4 to 36.4 μl · mg protein‐1· min.‐1 (on average 77 per cent) while muscular blood flow during exercise decreased significantly from 42.8 to 31.9 ml · 100 g‐1· min.‐1 (on average 23 per cent). Discontinuation of the training activities resulted in a return of the enzymatic activity to the pretraining values while the muscular blood flow appeared to remain low as long as five months after the training was stopped. Enzymatic adjustment to training appears to explain, at least partly, the haemodynamic changes observed during training.
Depletion of Liver Adenosine Phosphates and Metabolic Effects of Intravenous Infusion of Fructose or Sorbitol in Man and in the Rat*,**
Authors: Bode J. Ch. , Zelder O. , Rumpelt H. J. , Wittkampy U.
Published: March 2008

Summary. 1. The effect of parenteral administration of fructose and sorbitol on hepatic adenosine phosphates (AP) and intermediates of carbohydrate metabolism was examined in man and rat.—2. Intravenous injection of fructose rapidly decreases ATP, total adenosine phosphates (AP), and inorganic phosphate in the liver of fed male and female rats. The depletion in hepatic ATP and total AP is also observed in the regenerating rat liver following partial hepatectomy. Equimolar administration of sorbitol has the same effect on liver AP has that observed following fructose, while glucose administration produces no significant changes.—3. In man i.v. infusion of 0.6–0.8 g/kg body weight of fructose or sorbitol reduces hepatic ATP to about 50 %, and total AP to about 65 % of initial values. Glucose has no effect. Blood AP content is not affected by intravenous infusion of 500 ml of 10 % fructose in man.—‐4. Fructose distinctly increases the content of various hexose phosphates and triose phosphates in the liver of man. Fructose‐1‐phosphate accumulates 4‐to 5‐fold and α‐glycerophosphate 3‐fold during infusion of 0.6–0.8 g/kg body weight of fructose within 30 minutes.—5. RNA‐synthesis in the regenerating rat liver following partial hepatectomy as neasured by incorporation of 6‐14C‐orotic acid is distinctly inhibited by i. v. injection of 1.6 g of fructose kg. The incorporation rate of 1‐14C‐D, L‐leucine into rat liver protein drops to 35 % of initial levels within 10 minutes after the same amount of fructose, whereas glucose has no inhibitory effect.—6. Both ATP and Pi are important inhibitors of AMP degradation. Thus the drop in total AP content can be explained by the increased breakdown of the latter. This assumption is supported by the observation that injection of fructose plus equimolar amounts of Pi reduces the decrease in total AP, but not in ATP content. The concentration of the final product of AMP degradation, uric acid, increases distinctly following i. v. fructose administration in man.—7. These results indicate that in clinical medicine infusion of large doses of fructose or sorbitol have more disadvantages than advantages compared to glucose.
Effect of Nicotinamide on Carbohydrate Metabolism in the Rat Liver during Starvation
Authors: Talke H. , Maier K. P. , Kersten M. , Gerok W.
Published: March 2008

Abstract. A single high dose of nicotinamide (500 mg/kg body weight) results in an eight‐hour long inhibition of lipolysis in adipose tissue by transformation to nicotinic acid. In the present paper the effect of inhibited lipolysis on carbohydrate and amino acid metabolism after forty‐eight hours starvation was examined in vivo. Within two hours after the injection of nicotinamide (Nam) the plasma level of FFA declines from 900 μval/l to 300 μval/l. The FFA level rises again between 8–12 h after Nam injection. The reduced supply of FFA to the liver leads to a reduced oxidation rate, characterized by a fall in the acetyl‐CoA content of the liver and of ketone bodies in liver and blood. Simultaneously there is an increase in protein catabolism. This increase is characterized by increased urinary excretion of urea up to 10 h after Nam injection and by a higher urea production rate in liver slices of rats pretreated with Nam. In the liver the levels of the following amino acids rise very sharply SER (100%), CIT (400%), ORN (250%), ALA (300%), α‐AB (470%), VAL (350%), LEU (250%), ILE (370%). The content of THR is reduced to 63%, and GLY to 50%. In comparison to the values of the control groups the contents of ASP, GLU, TYR, LYS, HIS and ARG are unchanged.

The result of the increased precursor supply for gluconeogenesis is a higher rate of glucose production, characterized by an increase in blood glucose by 40 mg/100 ml, by an increase in liver glycogen content, by an increase in the concentrations of intermediates of the Embden‐Meyerhof‐pathway (mainly the concentrations of PEP (870%), 3PGA (480%), FDP (150%), G6P (250%) and glucose (220%). In liver slice experiments the glucose production rate from L‐ALA rises significantly, compared to the control group, after pretreatment of the animals with Nam. The results show that a stimulation of gluconeogenesis is obtainable in vivo, although the oxidation rate of FFA is reduced. Thus, they support the assumption, that an increased fatty acid oxidation rate is not a primary condition of stimulated gluconeogenesis.
Postheparin Plasma Lipase in Human Subjects.: Studies with Chylomicrons, Very‐Low Density Lipoproleins and a Fat Emulsion
Authors: Huttunen Jussi K. , Nikkilä Esko A.
Published: March 2008

Abstract. The properties of human postheparin lipolytic activity (PHLA) have been studied using an artificial triglyceride emulsion (Intralipid®), chylomicrons and endogenous lipoproteins as substrates. The assay system used requires only small amounts of plasma as the enzyme source and so reduces interference from the various activators and inhibitors present in plasma.

The pH‐activity curves of PHLA were characteristically flat for all three substrates used, the optimum being between 8.4 and 9.0. The apparent Km (as triglyceride) was lower for chylomicrons than for very low density lipoproteins (VLDL) or Intralipid°. Wide variation was found, in the effects of protamine sulphate and 1 M NaCl on PHLA. This variation depended both on the donor of PHLA and on the type of substrate used.

When the peak PHLA towards different substrates was compared in normal and hyperglyceridaemic subjects, an excellent correlation was found between the activities against chylomicrons and VLDL. The correlation between the activities towards endogenous substrates and Intralipid° was not so good. A significant negative correlation was observed between the fasting triglyceride level and lipolytic activity towards endogenous lipoproteins but not towards Intralipid°.

No difference was found in the rates of disappearance of the lipolytic activities towards chylomicrons and VLDL after injection of heparin, when the results from 20 subjects were pooled. After a change from a high‐fat to a high‐carbohydrate diet PHLA decreased on average by 40%, irrespective of the substrate used.

The results provide some further evidence for the presence of several triglyceride lipases in postheparin plasma. These upases may differ from each other both in substrate specificity and in their behaviour in the presence of various inhibitors.
Mercury‐Induced Renal Vascular Shut‐Down: Observations in Experimental Acute Renal Failure
Authors: Sherwood T. , Lavender J. P. , Russell S. B.
Published: March 2008

Abstract. Mercuric chloride introduced into the systemic circulation or directly into the renal artery in dogs leads to an immediate and lasting fall in renal blood flow. On arteriography severe cortical ischaemia is seen. These findings were studied in 32 animals. Renal vascular shut‐down induced by mercuric chloride appears concentration dependent, and is not mediated by glomerular filtration. It is possible to protect the kidney from shut‐down by an infusion of hyperosmolar mannitol given before mercuric chloride. This suggests that the ‘no‐reflow phenomenon’, already documented in the ischaemic kidney and brain, has a counterpart in mercury induced acute renal failure. Endothelial cell swelling may be an important primary vascular disorder underlying many acute renal failure states.
Metabolic Activity of Skeletal Muscle in Patients with Peripheral Arterial Insufficiency
Authors: Dahllöf Ann‐Gret , Björntorp P. , Holm J. , Scherstén T.
Published: March 2008

Abstract. 18 patients with intermittent claudication were studied to find some explanation for the beneficial effect of physical training on their symptoms. The patients were randomly allocated to a training group and a placebo‐treated control group. The effect of treatment on serum lipids, muscle lipids and glycogen, walking tolerance, calf blood flow, muscle succinic oxidase activity and the in vitro incorporation rate of glucose‐carbon into various metabolites were studied.

In the control group none of these parameters were changed.

In the trained group the following significant changes were found: Walking tolerance improved; muscle contents of cholesterol and phospholipids increased, as did succinic oxidase activity and the incorporation rate of glucose‐carbon into glycogen, lipids and carbon dioxide. Incorporation of glucose‐carbon into lactate decreased.

The improvement in walking tolerance was correlated with the altered pattern of metabolic activity but was not associated with increased calf blood flow. It is concluded that metabolic changes in skeletal muscles may be important in explaining the beneficial effects of physical training in patients with peripheral arterial insufficiency.
Inhibition of Active Hexose and Amino Acid Transport by Conjugated Bile Salts in Rat Ileum*
Authors: Caspary W.F.
Published: March 2008

Abstract. The effect of conjugated trihydroxy bile salts, tauro‐ and glycocholate, and of deoxycholate on tissue uptake and mucosal to serosal transfer of actively transported hex‐oses and amino acids has been examined in rat small intestine in vitro.

Conjugated trihydroxy bile salts and deoxycholate markedly inhibited active transport of hexoses and amino acids in the ileum of rat small intestine, whereas in the jejunum, deoxycholate alone was inhibitory. The inhibitory effect of tauro‐ and glycocholate increased with incubation time. It persisted after washing of the tissue and reincubation with hexoses in a bile salt free medium, and could be observed with only 2 × 10‐4 M taurocholate. Taurocholate was able to evoke an increase of transmural potential difference (PD) in the ileum, but did not affect PD in the jejunum. Prein cubation of ileal small intestine with taurocholate depressed subsequent glucose‐induced PD‐increments. In the jejunum, however, taurocholate did not affect PD‐increments induced by D‐glucose.

It is concluded that conjugated trihydroxy bile salts have to enter intestinal mucosal epithelial cells to an appreciable extent in order to affect other active, energy‐requiring transport systems in rat small intestine. Previous results showing a failure of conjugated bile salts to inhibit active transport of hexoses and amino acids are explained by the fact that only jejunal transport had been examined.
Isozymes of Aspartate Aminotransferase in Rat Liver during Acute Uraemia
Authors: Maier K. P. , Herz E. , Herz G. , Hoppe‐Seyler G. , Talke H. , Frohlich J. , Schollmeyer P. , Gerok W.
Published: March 2008

Abstract. Total activity of aspartate‐aminotransferase (GOT; EC 2.6.1.1) and activities of the cytoplasmic (c‐GOT) and mitochondrial (m‐GOT) isozymes were measured in rat liver 24 and 48 h after bilateral nephrectomy.

24 h after nephrectomy no significant differences in enzyme activities could be detected between uraemic animals and sham‐operated controls. However 48 h after nephthrectomy the total activity of GOT increased significantly. Fractional tissue extraction revealed an elevation of only the cytoplasmic isozyme (c‐GOT), due to a selective increase of this enzyme fraction. No significant change could be noticed of the mitochondrial isozyme (m‐GOT). These results are discussed with regard to an increased gluconeogenesis in rat liver 48 h after bilateral nephrectomy.
Abnormal Property of Human Mutant Hypoxanthine‐Guanine Phosphoribosyltransferase: Insensitivity of Fibroblast Enzyme to Stabilization against Freezing and Thawing by 5‐Phosphoribosyl‐1‐Pyrophosphate
Authors: Zoref E. , Sperling O. , de Vries A.
Published: March 2008

Abstract. Freezing and thawing of dilute normal human fibroblast suspensions causes partial inactivation of hypoxanthine‐guanine phosphoribosyltransferase (HGPRT) and adenine phosphoribosyltransferase (APRT). Phosphoribosyl‐pyrophosphate (PRPP) stabilizes both phosphoribosyltrans‐ferases against this inactivation. Mutant HGPRT enzymes from a patient with the Lesch‐Nyhan syndrome and from a gouty patient with partial HGPRT deficiency were similarly inactivated by freezing and thawing, but only the former mutant enzyme could be stabilized by PRPP. The insensitivity of the mutant HGPRT from the patient with partial enzyme deficiency to PRPP stabilization indicates a structural enzyme alteration. The different sensitivity of the two HGPRT mutants to PRPP stabilization reflects the heterogeneity of HGPRT mutations in man.
Bile Salt Sulphates in Cholestasis
Authors: Stiehl A.
Published: March 2008

Abstract. Bile salt sulphates were determined in serum and urine of 40 patients with severe cholestasis due to extrahepatic obstruction, hepatitis, cirrhosis and metastases of the fiver. Mono‐, di‐ and tri‐sulphates of bile salts were identified by column chromatography following intravenous administration of 14C‐cholate. Quantitative analysis was done by gas‐liquid chromatography following solvolysis. In our patients more than 50% of the bile salts excreted by the urine were sulphated (76.9% mono‐sulphates, 21.3% di‐sulphates, 1.8% tri‐sulphates). In contrast less than 10% of serum bile salts were sulphated. Therefore the renal clearance of bile salt sulphates was more than 15 times greater than the clearance of non‐sulphated bile salts. There were no significant differences in patients with extrahepatic obstruction, hepatitis, cirrhosis and metastases of the liver. – It is concluded that urinary excretion of mono‐ and di‐sulphates of bile salts represents an important excretory mechanism in patients with cholestatic liver disease. In most patients only trace amounts of tri‐sulphated bile salts were excreted in the urine.