bluuebunny/crossref_metadata_2025_split huggingface dataset:
Action of Angiotensin I Converting Enzyme Inhibitor on the Control of Renal Function in the Cat
Authors: Johns E. J. 
Published: August 2015

1. The renal responses to low level renal nerve stimulation and reduction in renal perfusion pressure within the autoregulatory range were measured before and after blockade of converting enzyme activity. Experiments were carried out using the unilaterally nephrectomized cat with the nerves of the remaining kidney acutely sectioned.
2. Renal nerves were stimulated to cause a 14% fall in blood flow for 15 min. Glomerular filtration rate was unchanged but sodium excretion and the ratio of sodium clearance to glomerular filtration rate fell significantly.
3. Renal nerve stimulation after blockade of converting enzyme activity was associated with a significant fall in glomerular filtration rate. The reductions in sodium excretion and in the ratio of sodium clearance to glomerular filtration rate were as large as in the absence of the blocking drug.
4. Reduction in renal perfusion pressure was associated with autoregulation of both renal blood flow and glomerular filtration rate but with large falls in sodium excretion and the ratio of sodium clearance to glomerular filtration rate.
5. After blockade of converting enzyme activity blood flow was still autoregulated in response to similar perfusion pressure reduction and glomerular filtration rate fell significantly. The ratio of sodium clearance to glomerular filtration rate, and sodium excretion, were reduced to the same extent as in the absence of the drug.
6. This information suggests that regulation of glomerular filtration rate associated with nerve stimulation or pressure reduction may be mediated by the intrarenal formation of angiotensin II, possibly acting at the efferent arteriole. They also indicate that angiotensin II is probably not involved in causing the increased sodium reabsorption.
Changes in Cholesterol Metabolism with Dietary Cholesterol in Children with Familial Hypercholesterolaemia
Authors: Martin Gillian M. , Nestel P. 
Published: August 2015

1. Possible defects in cholesterol metabolism were sought in children with familial hypercholesterolaemia.
2. In nine affected children (eight heterozygotes and one homozygote) and in five healthy children, cholesterol synthesis and bile acid synthesis were determined from the excretion of steroids in the faeces during a low cholesterol diet. Cholesterol synthesis of 10·1 ± 4·4 mg day−1 kg−1 in the hypercholesterolaemic children was similar to that in these and other normal children. Mean bile acid synthesis of 4·0 ± 2·1 mg day−1 kg−1 also resembled normal values though three severely affected heterozygotes excreted substantially less.
3. The response to 4 weeks' additional 450 mg of dietary cholesterol/day led to variable changes in the plasma cholesterol and in the sterol balance. On average the affected children showed a rise in plasma cholesterol which resembled that in healthy subjects. The sterol balance fell in most, suggesting a reduction in cholesterol synthesis, which is the normal response to dietary cholesterol.
4. The response to dietary cholesterol was therefore at least qualitatively similar in the hypercholesterolaemic children to that reported in healthy subjects.
Effect of Phenobarbitone on Plasma Apolipoprotein B and Plasma High-Density-Lipoprotein Cholesterol in Normal Subjects
Authors: Durrington P. N. 
Published: August 2015

1. Further observations from an earlier study in which phenobarbitone in a dose of 180 mg daily was administered to ten normal men and women for 3 weeks are reported. There was a significant increase in plasma high-denity-lipoprotein (HDL) cholesterol concentration and in the concentration of both total plasma and low-density-lipoprotein (LDL) apolipoprotein B.
2. There was no change in the ratios of the cholesterol: apolipoprotein B and triglyceride: apolipoprotein B in LDL.
3. There was no significant change in plasma very-low-density-lipoprotein (VLDL) apolipoprotein B concentration and the proportion of lipid and apolipoprotein B in VLDL remained unchanged.
4. There was no change in the ratio of HDL:LDL cholesterol concentrations.
Fractured Neck of Femur in the Elderly: An Attempt to Identify Patients at Risk
Authors: Wootton R. , Brereton P. J. , Clark M. B. , Hesp R. , Hodkinson H. M. , Klenerman L. , Reeve J. , Slavin G. , Tellez-Yudilevich M. 
Published: August 2015

1. During a 15-month period, 110 elderly patients admitted with fractured neck of femur were studied in comparison with 72 elderly control patients undergoing elective surgery admitted over the same period to the same orthopaedic wards.
2. A striking finding was the marked similarity of all variables measured in the fracture and control groups. The principal differences between the two populations were that the fracture patients had a lower mean forearm bone mineral content, and that their serum concentrations of albumin, globulin and phosphate were reduced.
3. Neither measurements of radioisotopic calcium absorption, nor those of the serum concentrations of calcium, 25-hydroxy-vitamin D3 nor alkaline phosphatase provided satisfactory discrimination between the groups.
4. Several indices were devised, based on linear combinations of the test results obtained, in an attempt to predict the liability to future fractures of patients being considered for prophylactic therapy with oestrogens or other drugs. However, further work is required to define an index of improved predictive power and to evaluate it prospectively.
Effect of Decrease in Bicarbonate Concentration on Metabolism of the Isolated Perfused Rat Kidney
Authors: Ross B. D. , Tannen R. L. 
Published: August 2015

1. An isolated perfused rat kidney preparation which responds to acidification of the perfusion medium with the production of an acid urine and increased ammonia production was used to study the metabolic regulation of ammonia production from glutamine.
2. An inhibitor of gluconeogenesis at phosphoenolpyruvate carboxykinase(GTP), mercaptopicolinate, completely prevented the increase in ammoniagenesis, without preventing acidification of the urine.
3. Acidification of the perfusion medium from pH 7·4 to 7·0 reduced the renal concentrations of malate and 2-oxoglutarate.
4. Malate concentration was restored by inhibition of phosphoenolpyruvate carboxykinase(GTP), but 2-oxoglutarate content remained low. This indicates that accelerated gluconeogenesis in acute acidosis cannot be the explanation for the fall in 2-oxoglutarate concentration.
5. The fall in 2-oxoglutarate content is taken to indicate an important fall in tissue pH or in the redox ratio (NAD+/NADH) or both during acute metabolic acidosis.
6. From these studies with lowered bicarbonate two separate stimuli to ammoniagenesis in acute metabolic acidosis are postulated: urinary trapping of ammonia and increased disposal of glutamine carbon atoms via the pathway of glucose synthesis.
Effects of β-Adrenoreceptor Antagonists on Sino-Aortic Baroreflex Sensitivity and Blood Pressure in Hypertensive Man
Authors: Watson R. D. S. , Stallard T. J. , Littler W. A. 
Published: August 2015

1. Sensitivity of the sino-aortic baroreflex was investigated before and after acute (23 patients) and chronic (23 patients) β-adrenoreceptor antagonism in patients with essential hypertension.
2. Sensitivity was inversely related to age (r = −0·60) and systolic blood pressure (r = −0·46); a positive relationship was noted between sensitivity and initial pulse intervals (r = 0·40).
3. Sensitivity increased significantly in patients less than 40 years of age after chronic treatment. No change occurred after acute treatment or in older patients treated chronically.
4. The fall in ambulatory intra-arterial blood pressure after chronic treatment was unrelated to alteration of baroreflex sensitivity.
Effect of Age on Hypertensive Stimuli and the Development of Hypertension in Brattleboro Rats
Authors: Dlouhá H. , Křeček J. , Zicha J. 
Published: August 2015

1. In rats with inherited diabetes insipidus, unilateral nephrectomy plus drinking of 0·6% NaCl solution (saline) did not influence blood pressure in adult rats. However, when these factors applied before puberty, they produced hypertension.
2. We therefore analysed whether saline administration before puberty or unilateral nephrectomy before puberty was more important for this hypertensive response.
3. Saline drinking was found to be necessary for the response because hypertension was elicited by unilateral nephrectomy in adult rats only if saline consumption began before puberty.
Peptiduria in Experimental Fanconi Syndrome in Rats
Authors: Asatoor A. M. , Bending M. R. , Milne M. D. 
Published: August 2015

1. The plasma concentrations and urinary output of proline and hydroxyproline contained in peptides were measured in normal rats and in rats with Fanconi syndrome produced by injection of sodium maleate. All animals received a prior injection of 10 mg of the dipeptide l-prolyl-l-hydroxyproline to increase plasma and urinary peptide content. There was a significant increase of urinary output of the two imino acids contained in peptides and a fall in their plasma concentrations.
2. It is concluded that increased output of peptides derived from collagen degradation in the experimental Fanconi syndrome in rats is at least in part due to diminished tubular reabsorption of these compounds from the glomerular filtrate. The results are claimed to be relevant to the increased output of urinary peptides in the Fanconi syndrome in man.
The Role of Dietary Lipid in the Regulation of Unconjugated Hyperbilirubinaemia in Gunn Rats
Authors: Gollan J. L. , Hole D. R. , Billing Barbara H. 
Published: August 2015

1. The purpose of this study was to characterize the mechanisms of diet-induced hyperbilirubinaemia in Gunn rats with emphasis on the role of lipids, and to examine their relationship with regard to fasting hyperbilirubinaemia.
2. A lipid-free normocaloric diet produced a threefold increase in plasma bilirubin concentration (baseline 109.4 μmol/l), which was maximal by 10 days and thereafter remained constant. The level of hyperbilirubinaemia attained was not influenced by fasting or phenobarbitone, and returned to baseline concentration within 10 days of resuming a normal diet.
3. Determination of hepatic bilirubin showed that the magnitude of the hepatic bilirubin pool was increased by the lipid-free diet but was unchanged by fasting. Hepatic ligandin concentrations were comparable in fasted Gunn rats and those fed normal or lipid-free diets, although total hepatic ligandin was reduced in the fasted animals.
4. The hyperbilirubinaemic effect of the lipid-free diet was largely reversed by the inclusion of 10% lipid in the diet and was affected to a lesser extent by 5% lipid. Similar reductions in plasma bilirubin concentration were observed with a variety of other lipids (10%), regardless of their fatty acid chain length or degree of saturation.
5. In fasting animals a direct correlation was observed between plasma bilirubin and free fatty acid concentrations and insulin levels were greatly depressed, whereas in those fed on the lipid-free diet no significant changes were evident in plasma concentrations of free fatty acids or insulin.
6. Plasma bilirubin concentration was unrelated to alterations in plasma triglycerides produced by the administration of clofibrate. However, an unexplained decrease in plasma bilirubin (40%) without a significant change in triglycerides was noted when clofibrate was added to the lipid-free diet.
7. Analysis of kinetic data obtained from [14C]bilirubin clearance studies revealed that hyperbilirubinaemia associated with the lipid-free diet reflected a marked reduction (60%) in plasma clearance with no change in bilirubin turnover. This was accompanied by a relative redistribution of bilirubin from the extravascular pool to the plasma pool.
8. Although these studies indicate that fasting and the withdrawal of dietary lipid have some similar effects on bilirubin metabolism, it seems likely that different mechanisms are responsible for the hyperbilirubinaemia.
A Micropuncture Study of Proximal Tubular Function after Acute Hydrochlorothiazide Administration to Brattleboro Rats with Diabetes Insipidus
Authors: Walter S. J. , Laycock J. F. , Shirley D. G. 
Published: August 2015

1. Renal function in anaesthetized Brattleboro rats with hereditary hypothalamic diabetes insipidus was studied with micropuncture techniques before, and 1–3 h after, a single injection of hydrochlorothiazide.
2. In rats given hydrochlorothiazide and kept in sodium and water balance, total glomerular filtration rate and superficial nephron filtration rate were similar to values in control animals, whereas fractional fluid reabsorption in the proximal tubule (as evidenced by tubular fluid/plasma inulin concentration ratios) was slightly, but significantly, reduced. This suggests that hydrochlorothiazide may have a small direct inhibitory effect on proximal tubular reabsorption.
3. When rats were given hydrochlorothiazide and the resultant extra urinary sodium losses were not replaced, there was a marked antidiuresis. In these animals total glomerular filtration rate was reduced by 23% and superficial nephron filtration rate by 27% when compared with values in control rats. Fractional proximal tubular fluid reabsorption increased significantly whereas absolute proximal fluid reabsorption was unaffected.
4. It is concluded that the reduction in body sodium which follows acute hydrochlorothiazide administration over-rides any inhibitory effect of the drug on proximal tubular reabsorption, and leads instead to an increase in fractional fluid reabsorption at this site. This effect, combined with the fall in glomerular filtration rate, results in a greatly reduced delivery of fluid to the more distal nephron segments, and is probably largely responsible for the observed antidiuresis.
Study of the Oligosaccharide Units from Mucus Glycoproteins of Meconium from Normal Infants and from Cases of Cystic Fibrosis with Meconium Ileus
Authors: Clamp J. R. , Gough M. 
Published: August 2015

1. The mucus glycoproteins in meconium from normal infants and from infants having cystic fibrosis with meconium ileus have been studied.
2. Whereas normal meconium contained about 50% protein-bound carbohydrate, the meconium from cystic fibrosis contained only about 10%.
3. Glycopolypeptides were prepared from the mucus glycoproteins. The oligosaccharide units from this material were released and fractionated. The fractions ranged widely in size and composition.
4. The fractions from cystic fibrosis specimens had a significantly higher content of fucose than those from normal specimens.
Lactoferrin Turnover in Man
Authors: Bennett R. M. , Kokocinski Theresa 
Published: August 2015

1. The turnover of 125I-labelled lactoferrin was measured in ten adults. Simultaneous organ radioactivity counting was performed.
2. Ferrokinetic studies were performed in three adults after the intravenous injection of [59Fe]lactoferrin.
3. Lactoferrin was rapidly eliminated from the plasma with a mean fractional catabolic rate of 5·7/day. Apolactoferrin (one subject) was eliminated at a slower rate (fractional catabolic rate 1·22/day).
4. Of the administered 125I label 99% was recovered in the urine, as free iodine, within the first 24 h. In the 59Fe studies no appreciable activity was found in the urine.
5. Organ radioactivity counting showed that lactoferrin was rapidly taken up by the liver and spleen. In the 125I studies the rapid excretion of free 125I suggested catabolism at these sites. In the 59Fe studies, the radioactivity persisted in the liver and spleen for several weeks and was slowly transferred to the bone marrow before appearing in circulating erythrocytes.
6. From the values of fractional catabolic rate, plasma lactoferrin, neutrophil lactoferrin and plasma volume, a ‘derived neutrophil turnover’ was calculated for each subject. The mean value was 8 × 108 neutrophils/day. This is about 1% the value obtained from the actual measurement of labelled cells. It is postulated that this ‘derived value’ represents only that portion of neutrophil turnover accounted for by intravascular senescence.
The Effect of Pentobarbitone on Plasma and Intracellular Sodium, Potassium and pH in Rabbit Cardiac and Skeletal Muscle
Authors: Hall R. J. C. , Cameron I. R. 
Published: August 2015

1. Pentobarbitone anaesthesia, in rabbits, produces (i) hypokalaemia, (ii) increased intracellular potassium and reduced intracellular sodium in cardiac and skeletal muscle.
2. These changes suggest that the hypokalaemia which accompanies anaesthesia results from movement of potassium between the extracellular and intracellular compartments.
Angiotensin II Blockade during Combined Thiazide—β-Adrenoreceptor-Blocker Treatment
Authors: Ibsen H. , Leth A. , McNair A. , Giese J. 
Published: August 2015

1. Sixteen patients (11 male, five female), median age 41 years, with essential hypertension insufficiently controlled by hydrochlorothiazide (75 mg/day; diastolic blood pressure ≥ 100 mmHg), were studied.
2. Plasma renin concentration [renin], plasma angiotensin II concentration ([ANG II]), plasma volume and exchangeable sodium (NaE) were determined, and a saralasin infusion (5·4 nmol min−1 kg−1) was carried out while the patients were on thiazide alone and, in 14 cases, 3 months after addition of a β-adrenoreceptor blocker (propranolol, six, metoprolol, six, and atenolol, two patients).
3. On thiazide alone, saralasin caused a significant decrease in mean arterial blood pressure in 12 out of 16 patients. The saralasin response was closely related to pre-saralasin plasma [ANG II] (r = −0·73, P &lt; 0·01). Plasma [renin] and [ANG II] were higher than normal in the group as a whole.
4. After addition of a β-adrenoreceptor blocker systolic and diastolic blood pressure decreased from 164/109 mmHg to 136/94 mmHg. Plasma [renin] and [ANG II] decreased by 40 and 58% respectively. At this point, saralasin caused no significant change in mean arterial pressure. No close correlation was found between plasma [renin] or [ANG II] or saralasin response on thiazide treatment and changes in blood pressure during subsequent thiazide/β-adrenoreceptor-blocker treatment. Plasma volume and NaE did not change significantly.
5. In patients with thiazide-induced stimulation of the renin—angiotensin system, addition of a β-adrenoreceptor blocker leads to suppression of the system and, at the same time, ANG II-dependence of blood pressure disappears. This contributes to the antihypertensive effect of β-adrenoreceptor blockers in this particular situation.
Captopril in Hypertension with Renal Artery Stenosis and in Intractable Hypertension; Acute and Chronic Changes in Circulating Concentrations of Renin, Angiotensins I and II and Aldosterone, and in Body Composition
Authors: Atkinson A. B. , Brown J. J. , Fraser R. , Leckie B. , Lever A. F. , Morton J. J. , Robertson J. I. S. 
Published: August 2015

1. The converting-enzyme inhibitor captopril has been given in doses up to 450 mg daily to hypertensive patients with renal artery stenosis and to patients resistant to other therapy.
2. Captopril alone was effective in controlling hypertension in renal artery stenosis, irrespective of whether pretreatment plasma angiotensin II was raised or normal, except in one man with overall renal impairment.
3. In one woman with the hyponatraemic hypertensive syndrome secondary to renal artery thrombosis, captopril restored depleted exchangeable sodium and potassium to normal. In the other cases of renal artery stenosis with normal renal function, exchangeable sodium and total body potassium were not significantly altered, and there were no marked changes in plasma sodium and potassium.
4. The combination of captopril with a diuretic controlled blood pressure long-term in every case of previously resistant hypertension.
5. Within 2 h, captopril induced highly significant falls in arterial pressure, in plasma angiotensin II and aldosterone, with converse increases in plasma active and total renin and blood angiotensin I.
6. The initial fall in plasma angiotensin II was closely related to the concomitant fall in diastolic pressure.
7. The pattern of change in circulating renin, angiotensins I and II and aldosterone was maintained during long-term therapy, whether or not a diuretic was added. There was no tendency for plasma angiotensin II to increase despite sustained elevation of active renin and angiotensin I.
Effect of Baroreceptor Deafferentation on Central Catecholamines in the Rat
Authors: Petty Margaret A. , Chalmers J. P. , Brown M. , Reid J. L. 
Published: August 2015

1. Sinoaortic deafferentation in the rat leads to increased blood pressure and heart rate.
2. Early increases in tyrosine hydroxylase activity both in brain stem and hypothalamus suggest that increased noradrenaline synthesis may contribute to the development of neurogenic hypertension.
3. After 4 weeks, phenylethanolamine-N-methyltransferase activity was reduced in the hypothalamus.
4. Noradrenaline- and adrenaline, but not dopamine-containing neurones may participate in regulation of sympathetic efferent activity.
The Kallikrein—Kinin System in Blood Pressure Homeostasis
Authors: Lee T. C. , Kushiro T. , Gassia J.-P. , Girolami J.-P. , Lupu A. N. , Maxwell M. H. 
Published: August 2015

1. The acute effects of the kallikrein inhibitor aprotinin (498 ki.u./min), and the kininase II inhibitor SQ 14 225 (250 μg), given intravenously during saralasin-induced angiotensin blockade, were studied in conscious sham-operated rats and rats with benign and malignant two-kidney, one-clip Goldblatt hypertension during dietary sodium restriction.
2. The blood pressure of conscious sham-operated rats increased significantly in response to aprotinin. It remained unchanged after SQ 14 225 in contrast to the significant vasodepressor effect seen when SQ 14 225 was given to the same rats under surgical stress and pentobarbital anaesthesia.
3. Benignly hypertensive rats showed a consistent vasopressor response to aprotinin and a marked vasodepressor response to SQ 14 225. The effects of both inhibitors were markedly and significantly blunted in malignantly hypertensive rats.
4. Our demonstration that two agents with known opposite actions on the kallikrein—kinin system produced predictable and opposite effects on blood pressure may indicate that this system is involved in the homeostatic regulation of blood pressure. It may play an important antihypertensive role in benign two-kidney, one-clip Goldblatt hypertension, a role which might be impaired in malignant hypertension.
Studies on the Mechanism of Mineralocorticoid-Induced Blood Pressure Increase in Man
Authors: Distler A. , Philipp T. , Lüth B. , Wucherer G. 
Published: August 2015

1. To gain insight into the mechanism of mineralocorticoid-induced blood pressure rise in man we performed haemodynamic studies in six normotensive volunteer subjects before and during administration of the synthetic steroid 9α-fluorocortisol (0·8 mg daily) for a period of 6 weeks. In a further study, performed in seven subjects, plasma noradrenaline concentration and reactivity to exogenous noradrenaline were determined before and during administration of the mineralocorticoid.
2. Within the first week of steroid administration an increase in mean arterial blood pressure could be demonstrated, which was due to an increase in cardiac output. After the sixth week the elevated blood pressure was the consequence of an increased total peripheral resistance.
3. Plasma noradrenaline concentration decreased and reactivity to exogenous noradrenaline increased during steroid administration.
4. The mechanism underlying the increase in total peripheral resistance during long-term mineralocorticoid administration remains unclear. Increased sympathetic tone does not seem to be a factor since plasma noradrenaline decreased considerably. Pressor response to noradrenaline increased probably due to decreased sympathetic tone.