bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Relationship between the Formation of Urea and Argininosuccinate in a Patient with Argininosuccinic Aciduria Studied with Labelled Precursors
Authors: Crane C. W. , Jenner F. A. , Pollitt R. J. 
Published: August 2015

1. The time-course of urinary excretion of [15N]urea and [15N]argininosuccinate or [15N]arginine after an oral dose of [15N]ammonium lactate has been followed in patients with argininosuccinic aciduria and cystine-lysinuria respectively. The labelled argininosuccinate and arginine appeared more slowly than expected on simple precursor-product models.
2. In the patient with argininosuccinic aciduria, simultaneous ingestion of [15N]-ammonium lactate and [carbamoyl-14C]citrulline gave very different ratios of labelling with the two isotopes for urinary urea and argininosuccinate. Urinary argininosuccinate had not been in equilibrium with the urea precursor in this patient, but the plasma [14C]citrulline bore a reasonable precursor-product relationship to the urinary [14C]argininosuccinate.
3. Intravenous [guanidino-14C]arginine given to the patient with argininosuccinic aciduria resulted in a much higher degree of labelling of the plasma globulins than the albumin. This is consistent with a considerable turnover of hepatic arginine, as would be expected with a functioning Krebs-Henseleit urea cycle.
4. These results can be explained with a compartmentation model in which most of the urea is synthesized in the liver, but most of the urinary argininosuccinate is peripheral in origin.
Rapid Transfer of Folic Acid from Blood to Bile in Man, and its Conversion into Folate Coenzymes and into a Pteroylglutamate with Little Biological Activity
Authors: Lavoie A. , Cooper B. A. 
Published: August 2015

1. [3H]Folic acid infused intravenously into patients with biliary fistulae appeared promptly in bile, coincident with 131I-labelled Rose Bengal injected simultaneously. The radioactivity was distributed among several fractions of biological folates present in bile and was associated with folic acid and with an unidentified folate which chromatographed on DEAE-Sephadex close to 10-formyltetrahydrofolyl monoglutamate.
2. Based on affinity for DEAE-Sephadex and support of growth of Lactobacillus casei, Streptococcus faecalis and Pediococcus cerevisiae, we have tentatively identified some of the folates of human bile as 10-formyltetrahydrofolate, 10-formylfolate, 5-formyltetrahydrofolate, 5-methyltetrahydrofolate and tetrahydrofolate or 5,10-methylene tetrahydrofolate. After infusion of folic acid, the formyltetrahydrofolates increased more rapidly than did 5-methyltetrahydrofolate.
3. The unidentified radioactive folate contained both the pteridine and p-aminobenzoate portions of folate. It appeared not to support growth of the test microorganisms and not to be bound to a protein or a chain of γ-glutamates. It was present in the bile of a dog injected with [3H]folic acid but was absent from extracts of liver. This material may be a transport form of folate or a special modification imposed on folic acid during transport across the liver.
Lipoprotein Lipase in Human Adipose Tissue
Authors: Elkeles R. S. 
Published: August 2015

1. The presence of lipoprotein lipase has been confirmed in acetone-ether extracts of human adipose tissue.
2. The properties of the enzyme appear to be similar to that in rat adipose tissue though it is less active on a weight basis.
3. The presence of a separate monoglyceride lipase has been demonstrated in human adipose tissue.
4. In eluates of human adipose tissue the activity of lipoprotein lipase is dependent on heparin, whereas that of the monoglyceride lipase does not require heparin.
5. No consistent effect of insulin in vitro on the enzyme in human adipose tissue has been demonstrated. Possible reasons for this are discussed.
Albumin and Creatinine Clearances in Renal Disease
Authors: Lavender S. , Bennett J. , Morse P. F. , Polak A. 
Published: August 2015

1. The ratio of albumin clearance to creatinine clearance (CA/CC) was determined on 129 occasions in forty patients with a wide variety of renal diseases, both 24 h collections of urine and random mid-morning samples being used. The clearance ratios derived from 24 h urine (24 h CA/CC) and random urine (R CA/CC) were compared with random urine protein concentration, 24 h urine protein excretion and 24 h urine albumin excretion.
2. From these measurements 24 h CA/CC could only be predicted accurately by R CA/CC, particularly when patients with postural proteinuria were excluded.
3. The diurnal variation of CA/CC was investigated in twelve patients with renal disease. The individual values for CA/CC obtained throughout the day were within the limits of prediction of 24 h CA/CC already established. The diurnal variation of CA/CC was considerably less than that of CA or CC alone and also less than that of the rates of protein and albumin excretion.
4. It is suggested that CA/CC is the best readily available measure of ‘glomerular leakiness’ and examples are given of its clinical value. In patients with renal disease 24 h CA/CC could be predicted, in this study, from the clearance ratio based on simultaneous random urine and blood samples.
Variations in Allopurinol Metabolism by Xanthinuric Subjects
Authors: Simmonds H. A. , Levin B. , Cameron J. S. 
Published: August 2015

1. The metabolism of allopurinol was studied in a newly discovered patient with xanthinuria.
2. No oxipurinol was detectable in the urine during allopurinol administration, in direct contrast to the results in a patient previously studied by one of us.
3. Other equally discrepant effects of allopurinol on urinary purine and pyrimidine excretion in these two cases are compared with those in the three other recorded cases.
The Effect of Brain Extracts on Urinary Sodium Excretion of the Rat and the Intracellular Sodium Concentration of Renal Tubule Fragments
Authors: Clarkson E. M. , Koutsaimanis K. G. , Davidman M. , Du Bois M. , Penn W. P. , De Wardener H. E. 
Published: August 2015

1. Extracts were prepared from bovine hypothalamus and cerebral cortex by gel filtration on Sephadex G-25 and G-50.
2. The vasopressin in the hypothalamic extracts was inactivated with thioglycollate and the effectiveness of inactivation was tested in the alcohol-anaesthetized rat.
3. The inactivated hypothalamic extracts caused a significant rise, and the cortical extracts an insignificant fall, in the urinary sodium excretion of the conscious rat.
4. Incubation of tubule fragments in hypothalamic extracts caused a significant rise in intracellular sodium concentration of the tubules when compared with incubation in Ringer, whereas incubation in cortical extracts caused a rise which was not significant. Nevertheless the rise in intracellular sodium concentration produced by incubating the tubules in hypothalamic extracts was not significantly different from the rise produced by incubation in cortical extracts.
Blood Pressure Changes Produced by Kidney Cross-Transplantation between Spontaneously Hypertensive Rats and Normotensive Rats
Authors: Bianchi G. , Fox U. , Di Francesco G. F. , Giovanetti A. M. , Pagetti D. 
Published: August 2015

1. From a single strain of Wistar rats two lines of normotensive rats (NR) and two lines of hypertensive rats (SHR) were developed by selective breeding.
2. One line of normotensive rats and one of hypertensive rats were used as recipients and the remaining two were used as donors for cross-transplantation of kidneys from hypertensive to normotensive rats and vice versa. Transplantations between the two hypertensive lines and the two normotensive ones were carried out to provide animals for control studies.
3. Normotensive recipients of kidneys from SHR developed hypertension whereas the recipients of kidneys from NR remained normotensive. The serum urea changes were equal in both groups.
4. Transplantation of normotensive kidneys reduced the blood pressure of hypertensive recipients, but transplantation of hypertensive kidneys did not alter blood pressure. The serum urea concentrations were higher in the recipients of hypertensive kidneys. These results, obtained in 3–4-month-old rats, indicate that the kidneys of adult hypertensive rats are involved in the maintenance of hypertension.
5. To evaluate whether the kidneys from hypertensive rats may also initiate hypertension, young normotensive recipients were given kidneys taken from the NR or SHR strain while the latter were still normotensive. Transplantation of kidneys from these SHR donors resulted in significantly higher blood pressure values and serum urea concentrations than transplantation of kidneys from NR donors.
The Inhibition of Renin Secretion by Alpha-Adrenergic Stimulation in the Isolated Rat Kidney
Authors: Vandongen R. , Peart W. S. 
Published: August 2015

1. The respective role of alpha-adrenergic and beta-adrenergic receptors in mediating the effect of catecholamines on renin secretion was examined in the isolated perfused rat kidney.
2. Noradrenaline, which has combined alpha- and beta-adrenergic activity, stimulated renin secretion only in the presence of the alpha-receptor blocking agent phenoxybenzamine. This stimulatory effect was largely prevented by the addition of the beta-blocking agent, propranolol. The vasoconstrictor action of noradrenaline, and thus the rise in mean renal perfusion pressure, was abolished by phenoxybenzamine. Our previous finding that noradrenaline alone stimulated renin release was inconclusive (Vandongen, Peart & Boyd, 1973).
3. Noradrenaline stimulated renin secretion when calcium was excluded from the perfusion fluid, to which disodium EDTA (25 mmol/l) was added. The vasoconstrictor action of noradrenaline was considerably attenuated under these conditions.
4. Methoxamine, which has only alpha-adrenergic activity, did not increase renin secretion when infused alone or with phenoxybenzamine. The increase in renin secretion after beta-adrenergic stimulation with isoproterenol was significantly suppressed by methoxamine, although this was associated with an increase in mean renal perfusion pressure.
5. These findings indicate the importance of intrarenal beta-adrenergic receptors in the stimulation of renin secretion and suggest that an opposite inhibitory effect on renin secretion follows alpha-adrenergic activity.
6. Although the results do not exclude a direct effect of vascular tone and renal perfusion pressure, it is suggested that the stimulation and inhibition of renin secretion is related to smooth muscle activity by the involvement of a calcium-dependent process similar to that involved in contraction and relaxation. This would accord with the common derivation of the renin-producing and vascular smooth muscle cells
Human Erythrocyte Glutathione Reductase and Glucose 6-Phosphate Dehydrogenase Activities in Normal Subjects and in Persons Exposed to Lead
Authors: Howard J. K. 
Published: August 2015

1. Blood lead and erythrocyte glutathione reductase (GSSG-R) and glucose 6-phosphate dehydrogenase (G6P-D) activities were measured in normal subjects and in those with occupational exposure to lead.
2. With increasing blood lead concentration, GSSG-R activity increases and that of G6P-D decreases.
3. It is suggested that these changes represent part of a compensatory mechanism to overcome the reduction of sulphydryl groups by lead ions.
Human Parathyroid Hormone: Immunological Properties of the Amino Terminus and of Synthetic Fragments
Authors: Hendy G. N. , Barling P. M. , O'Riordan J. L. H. 
Published: August 2015

1. Immunological assay systems specific to the amino-terminal region of parathyroid hormone were used to study the properties of human parathyroid hormone (HPTH 1-84) and of synthetic peptides. One of these peptides (HPTH 1-34A) had the sequence proposed by Niall, Sauer, Jacobs, Keutmann, Segre, O'Riordan, Aurbach & Potts (1974). The others (HPTH 1-34B and C, synthesized by different methods) had the sequence proposed by Brewer, Fairwell, Ronan, Sizemore & Arnaud (1972).
2. HPTH 1-84 and HPTH 1-34A behaved identically in a number of these systems. In some systems, especially those using antisera obtained by immunizing with HPTH 1-34A, differences were, however, found. These may be due to conformational or other physical differences or to the presence of an immunologically incomplete site in the fragment.
3. In systems in which HPTH 1–84 and HPTH 1-34A behaved identically the peptides with the sequence proposed by Brewer et al. (1972) were of low reactivity by 100–2000-fold.
Uranyl Nitrate Acute Renal Failure in the Dog: Early Changes in Renal Function and Haemodynamics
Authors: Kleinman J. G. , McNeil J. S. , Flamenbaum W. 
Published: August 2015

1. Sodium excretion, plasma renin activity (PRA), inulin clearance, total renal blood flow (RBF), renal cortical radiomicrosphere distribution and systemic haemodynamics were examined during the first 3 h after intravenous administration of uranyl nitrate (19.9 μmol/kg body wt.; 10 mg/kg) in the dog.
2. During the 3 h of study after uranyl nitrate, urine flow remained stable or increased, sodium excretion increased approximately fivefold, renal vascular resistance increased threefold, and concordant decreases in RBF and inulin clearance to 40–50% of control values occurred. At 3 h total cortical RBF decreased to 35% of control values and the ratio of blood flow in outer to inner cortical zones also decreased, reflecting outer cortical ischaemia. PRA increased in the first hour after uranyl nitrate and slowly declined thereafter, though not to control values.
3. Respiratory rate, heart rate, mean systemic blood pressure and cardiac output were unchanged after uranyl nitrate, demonstrating that the changes in renal vascular resistance occurred without a change in peripheral vascular resistance.
4. It is postulated that increased renin-angiotensin system activity mediates the change in renal haemodynamics and the consequent fall in glomerular filtration.
Plasma Adenosine 3′:5′-Cyclic Monophosphate Response to Glucagon in Thyroid Disease
Authors: Elkeles R. S. , Lazarus J. H. , Siddle K. , Campbell A. K. 
Published: August 2015

1. The plasma adenosine 3′:5′-cyclic monophosphate (cyclic AMP) response to intravenously administered glucagon has been studied in nine hyperthyroid, five hypothyroid and ten euthyroid patients.
2. Concentrations of the nucleotide rose to a peak at 15 min and declined to near basal values by 120 min, the response being greatest in hyperthyroid and least in hypothyroid subjects. The mean peak concentrations were 1028 nmol/l in the hyperthyroid group, 252 nmol/l in the hypothyroid group and 534 nmol/l in the euthyroid group.
3. These results could not be accounted for by differences in serum insulin response.
4. It is suggested that the response of plasma cyclic AMP to glucagon may serve as an index of tissue thyroid status.
Renal Circulatory Responses to General Anaesthesia in the Rabbit: Studies Using Radioactive Microspheres
Authors: Warren D. J. , Ledingham J. G. G. 
Published: August 2015

1. Total renal blood flow and its cortical distribution were measured by the radioactive microsphere technique in conscious rabbits and after anaesthesia with pentobarbitone, chloralose-urethane or ether.
2. Pentobarbitone anaesthesia caused a fall of 26% in total renal blood flow, of 26% in superficial cortical flow, and of 24% in deep cortical flow. Sodium excretion rate fell by 33%.
3. Chloralose-urethane anaesthesia caused no change in total or regional renal blood flow, or in sodium excretion.
4. Ether anaesthesia caused an insignificant fall in total renal blood flow, but superficial cortical flow fell by 13 % and deep cortical flow rose by 21 %. Urinary sodium excretion fell by 65%.
5. Possible mechanisms for these changes in response to anaesthesia are discussed.
6. The effects of anaesthetic agents may influence the interpretation of published work on control mechanisms in the renal circulation.
Detection of Low-Renin Hypertension; Evaluation of Out-Patient Renin-Stimulating Methods
Authors: Drayer J. I. M. , Kloppenborg P. W. C. , Benraad T. J. 
Published: August 2015

1. Three renin-stimulating methods for detection of low-renin hypertension have been compared. First, renin activity was measured in hospital patients after 5 days of sodium restriction and 3 h ambulation. Secondly, renin activity was measured after frusemide stimulation [0.42 mmol (140 mg) in 18 h] and 3 h ambulation. Thirdly, renin activity was measured after 5 days of chlorthalidone treatment [0.3 mmol (100 mg)/day] and 3 h ambulation. The last two tests were done with the subjects as out-patients without any dietary regimen.
2. In eleven normotensive control subjects and twenty hypertensive patients the results after frusemide were not comparable with those after sodium restriction since the frusemide test did not identify the same renin-suppressed hypertensive subjects as the sodium-restriction procedure.
3. After 5 days of chlorthalidone treatment the renin values in eleven control subjects as well as in thirty-eight hypertensive patients were significantly higher than after sodium restriction. The values obtained after each procedure were closely correlated.
4. Thus the out-patient chlorthalidone procedure identified similar sub-groups of patients as having low- or normal-renin hypertension as did the in-patient sodium-restriction test.
The Assessment of Acid-Base Disturbance in Man by the Use of Carbon Dioxide Titration Curves
Authors: Stoker J. B. , Kappagoda C. T. , Snow H. M. , Linden R. J. 
Published: August 2015

1. Carbon dioxide titration curves were determined in vivo in dog and man at various degrees of acute non-respiratory acidaemia and alkalaemia.
2. The slope of the CO2 titration curve (Δlog Pco2/ΔpH) was found to increase with the severity of the acute non-respiratory acidaemia. In states of acute non-respiratory alkalaemia the slope (Δlog Pco2/ΔpH) tended towards unity.
3. A simple scheme based on the CO2 titration curves determined in vivo has been proposed for the assessment of acute acid-base disturbances in man.
4. Carbon dioxide titration curves were also determined in vivo in patients with chronic respiratory and non-respiratory acidaemia and it was found that these curves were not significantly different from those obtained in states of acute acid-base disturbances. It is therefore suggested that the scheme described in this paper is applicable to all acid-base disturbances.
Inhibition of the Pressor and Aldosterone-Releasing Effects of Angiotensin II
Authors: Bumpus F. M. , Khosla M. C. 
Published: August 2015

1. Competitive or non-competitive inhibition of the myotropic and pressor response of angiotensin II is dependent on the nature of the substituent in position 8 of the antagonist peptide analogue. Substituents in other positions of the molecule, particularly position 1, contribute greatly to the potency of these antagonists.
2. As is evidenced after adrenalectomy or after blockade with phentolamine and phenoxybenzamine, the initial pressor activity observed with all the antagonistic peptides is partially due to the release of catecholamines and partially to a direct myotropic effect.
3. [Sar1, Thr8]angiotensin II has been found to possess the lowest agonist to antagonist ratio of all antagonists tested.
4. [Des-Asp1, Ile8]angiotensin II selectively and specifically inhibits the release of aldosterone from adrenal cortex. Thus, unlike angiotensin II, this heptapeptide has pronounced organ specificity, suggesting that the heptapeptide (angiotensin III) is the aldosterone-releasing hormone.
The Effect of 1,25-Dihydroxycholecalciferol on Renal Tubular Reabsorption of Phosphate, Intestinal Absorption of Calcium and Bone Histology in Hypophosphataemic Renal Tubular Rickets
Authors: Russell R. G. G. , Smith R. , Preston C. , Walton R. J. , Woods C. G. , Henderson R. G. , Norman A. W. 
Published: August 2015

1. 1,25-Dihydroxycholecalciferol (1,25-(OH)2-D3) was given at a dose of 5.0 nmol (2.1 μg) daily by mouth for 4–12 days to three patients with hypophosphataemic (type I), vitamin D-resistant rickets.
2. 1,25-(OH)2-D3 increased intestinal absorption and urinary excretion of calcium without significant effect on the renal handling of phosphate or its plasma concentration.
3. It is concluded that in this type of vitamin D-resistant rickets the renal phosphate abnormality is unlikely to be due to diminished endogenous production of 1,25-(OH)2-D3.
4. The difference between this condition and other hypophosphataemic states is discussed.
Comparative Pharmacology of New Specific Angiotensin Antagonists
Authors: Schoelkens B. A. 
Published: August 2015

1. The angiotensin II antagonism by newly synthesized 8-C-phenylglycine analogues of [5-isoleucine]angiotensin II in different preparations was investigated in vitro and in vivo.
2. All analogues competitively inhibited the myotropic effect of angiotensin II on the isolated colon ascendens of the guinea-pig and the stomach of the rat.
3. In normotensive dogs, cats, rabbits, guinea-pigs and rats the blood pressure response to infused angiotensin II was inhibited by the antagonists. The angiotensin II-induced fall in renal blood flow in the dog was blocked during infusion of the analogues. Acute renal hypertension in rats was significantly decreased. Of conscious rats variously with normal blood pressures, spontaneous hypertension and chronic renal hypertension, only in the last group could a marked uniform fall in blood pressure be demonstrated. The central pressor effect of angiotensin II was also inhibited in conscious rats.
4. 8-C-Phenylglycine analogues of [5-isoleucine]-angiotensin II exhibit a specific antagonistic activity to endogenous and exogenous angiotensin II.
Effect of Single and Combined Infusions of Angiotensin II and Aldosterone on Colonic Potential Difference, Blood Pressure and Renal Function, in Patients with Adrenal Deficiency
Authors: Efstratopoulos A. D. , Peart W. S. 
Published: August 2015

1. The effect of single and combined infusions of angiotensin and aldosterone on colonic potential difference, blood pressure and renal function was studied in two normal male subjects and four female patients with adrenal deficiency maintained only on cortisone.
2. Aldosterone had its usual effect on colonic potential difference and it was possible to show that angiotensin had a small but definite effect of its own in the absence of aldosterone. The two hormones produced a summation response when given together.
3. The effects on renal function in two normal young male subjects were similar to those known previously. The response of the patients was different and probably reflected a number of factors, such as age, sex and long-standing adrenal deficiency.
4. Although the numbers were small, both normal subjects and patients showed a significantly greater rise of blood pressure with combined infusions of angiotensin and aldosterone than with angiotensin alone. The plasma concentrations of angiotensin were similar with both types of infusion, and so increased sensitivity to angiotensin in the presence of aldosterone is postulated.
Feedback Regulation of 25-Hydroxycholecalciferol Metabolism by Vitamin D3
Authors: Evans I. M. A. , Colston K. W. , Galante L. , MacIntyre I. 
Published: August 2015

1. In vitamin D-deficient chicks both vitamin D3 and 1α-hydroxycholecalciferol markedly decrease renal 1-hydroxylase activity and induce 24-hydroxylase activity.
2. Actinomycin D abolishes both effects.
3. These results are consistent with feedback regulation of vitamin D3 metabolism by a direct nuclear action of the vitamin or its metabolites on the kidney cells.