bluuebunny/crossref_metadata_2025_split huggingface dataset:
Implications of Prostacyclin Generation for Modulation of Vascular Tone
Authors: Dusting G. J. , Moncada S. , Mullane K. M. , Vane J. R. 
Published: August 2015

1. The biotransformation of arachidonic acid and prostacyclin in the circulation was studied in anaesthetized dogs, using the blood-bathed organ technique.
2. In passage through the lungs, arachidonate (50–800 μg kg−1 min−1) was transformed into prostacyclin. No thromboxane A2 or prostaglandin E2 could be detected in arterial blood.
3. In dogs treated with indomethacin (5 mg/kg), intravenous infusions of arachidonate had no cardiovascular effects and no prostacyclin was produced. Therefore, the vasodilator effects of arachidonate in vivo may be attributable to prostacyclin formation.
4. Prostacyclin, unlike prostaglandin E2, is not inactivated by passage across the lungs, and only about 50% disappears in one passage through peripheral vascular beds.
5. Thus prostacyclin released from the lungs could function as a circulating vasodilator and contribute to the regulation of blood vessel tone and blood pressure.
Endogenous Prostaglandin Synthesis Inhibitor in the Renal Cortex. Effects on Production of Prostacyclin by Renal Blood Vessels
Authors: Terragno Norberto A. , Terragno Alicia , Early Judith A. , Roberts Mary A. , McGiff John C. 
Published: August 2015

1. The capacity of various tissues of the porcine kidney to convert [1-14C]arachidonic acid into radiolabelled prostaglandins was studied.
2. Only after removal from the cortical matrix, were renal blood vessels able to convert arachidonic acid into prostaglandins (primarily prostacyclin). In contrast, convoluted tubules showed a low capacity to metabolize arachidonic acid.
3. The failure to demonstrate prostaglandin synthesis by renal cortical slices is related to the presence of an inhibitor of cyclo-oxygenase. Thus, the addition of renal cortical incubate to isolated vascular tissues and ram seminal vesicles inhibited their ability to synthesize prostaglandins.
4. Slices of renal medulla metabolized arachidonic acid primarily to prostaglandin F2α; lesser amounts of prostaglandin E2 and prostacyclin were generated.
5. The large capacity of the renal vasculature to generate prostacyclin is consistent with an important role for this prostaglandin in regulation of renin release and renal haemodynamics.
Intrarenal Control of Urine Concentration by Angiotensin II
Authors: Imbs J. L. , Schmidt M. , Schwartz J. 
Published: August 2015

1. The intrarenal role of angiotensin II in the recovery of urinary concentration after frusemide was examined in anaesthetized dogs by the intrarenal infusion of angiotensin II antagonists.
2. Renin secretion and renal inner medullary blood flow (tissue clearance of intraparenchymatously injected 133Xenon) were simultaneously measured before and 3 h after frusemide injection.
3. Intrarenal angiotensin II blockade delayed the recovery of urinary osmolality after frusemide.
4. An inverse relationship was found between renin secretion and renal inner medullary blood flow.
The Role of Vasopressin in Blood Pressure Control and in Experimental Hypertension
Authors: Pullan P. T. , Johnston C. I. , Anderson W. P. , Korner P. I. 
Published: August 2015

1. The role of vasopressin in blood pressure control and in the pathogenesis of one-kidney Goldblatt hypertension in the conscious dog was investigated.
2. Infusion of synthetic arginine vasopressin to elevate plasma levels approximately five-fold caused bradycardia in normal dogs and increase in mean arterial blood pressure in dogs with pharmacological autonomic blockade.
3. A similar degree of elevation of plasma vasopressin concentration was observed after mild non-hypotensive haemorrhage.
4. Renal artery constriction in unilaterally-nephrectomized dogs caused a rise in plasma renin activity and only a doubling of plasma vasopressin concentration, but a marked rise in mean arterial blood pressure.
5. Vasopressin may play a role in normal cardiovascular homeostatic responses, but its role in the pathogenesis of this form of hypertension is unlikely to be significant.
Pharmacokinetics of Intravenous and Oral Pindolol in Hypertensive Patients with Chronic Renal Failure
Authors: Safar M. E. , Chau N. Ph. , Levenson J. A. , Simon A. Ch. , Weiss Y. A. 
Published: August 2015

1. The pharmacokinetics of intravenous and oral pindolol were determined in 24 hypertensive patients with normal or impaired renal function.
2. In patients with normal renal function, the total clearance of the drug was the sum of both the renal and non-renal clearances in equal parts. The non-renal clearance was found to equal the hepatic clearance directly measured from the hepatic extraction ratio and hepatic blood flow.
3. Compared with patients with normal renal function, patients with chronic renal failure exhibited (i) unchanged transfer rate constants and distribution volumes, (ii) decreased total body clearance with decreased renal clearance and unchanged non-renal clearance.
4. Analysis of data obtained after oral administration of the drug by the Loo—Riegelman method showed that the pindolol absorption kinetic was non-linear. Compared with patients with normal renal function, patients with chronic renal failure exhibited (i) a significantly decreased fraction of dose effectively absorbed, (ii) an increased initial rate of absorption. The initial rate of absorption was inversely correlated with creatinine clearance.
5. The study provided evidence that in patients with renal insufficiency, (i) no increase in the metabolism of the drug accompanied the decrease in renal function, and (ii) decreased bio-availability was associated with a reduced fraction of the dose effectively absorbed and an increased rate of absorption.
Maximal Discrimination of Renovascular from Essential Hypertension by the Saralasin Test
Authors: Maxwell M. H. , Varady P. , Zawada E. T. , Burkhalter J.-F. , Waks U. , Marks L. 
Published: August 2015

1. Thirty-four patients with essential hypertension and 37 with proven renovascular hypertension were tested with saralasin after frusemide-induced diuresis.
2. Variables used for analysis were: pre-saralasin plasma renin activity (PRA), post-saralasin PRA, and ratios of systolic and diastolic blood pressures (saralasin blood pressure/control blood pressure).
3. Stepwise linear discriminant analysis demonstrated that the most significant variables were diastolic ratio, systolic ratio, and post-saralasin PRA.
4. Minimal misclassification (14·1%) was achieved by combining diastolic ratio, baseline supine PRA and post-saralasin PRA; but using post-saralasin PRA alone resulted in misclassification of only 15·5% (7 essential hypertension and 4 renovascular hypertension).
5. Thus, PRA increased disproportionately after saralasin in renin-dependent renovascular hypertension because of the fall in blood pressure and/or interruption of the short, negative angiotensin II feedback loop.
6. It is concluded that the rise in PRA after the combined stimuli of volume depletion and saralasin is more sensitive than the fall in blood pressure in discriminating between essential hypertension and renovascular hypertension, although minimal misclassification is achieved by analysing baseline PRA, diastolic ratio and post-saralasin PRA simultaneously.
Treatment of Mild Hypertension
Authors: Morgan T. , Adam W. , Gillies A. , Carney S. 
Published: August 2015

1. A total of 206 patients, elderly males with hypertension (diastolic blood pressure 95–110 mmHg) were followed for periods varying from 1 to 5 years, 107 patients with diastolic blood pressure <95 mmHg were followed over the same period, and 101 patients with diastolic blood pressure ≥110 mmHg were also followed.
2. The mortality of each group and the effect of therapy for hypertension on mortality has been compared.
3. The incidence of myocardial infarct in the group treated with thiazide diuretics is greater than in the other groups.
4. It would appear unlikely that therapy will improve the prognosis in elderly people with mild hypertension.
Increased Ratio between Serum β- and α-Lipoproteins during Diuretic Therapy: An Adverse Effect?
Authors: Glück Z. , Baumgartner G. , Weidmann P. , Peheim E. , Bachmann C. , Mordasini R. , Flammer J. , Keusch G. 
Published: August 2015

1. The effect of diuretic therapy on serum lipids and lipoprotein fractions was evaluated in 16 normal or labile hypertensive subjects who received in cross-over fashion chlorthalidone, frusemide or mefruside, each for 4 weeks (group A); and in 13 patients with essential hypertension treated with chlorthalidone for 6 weeks (group B).
2. All three diuretics significantly increased the ratio between serum β- and α-lipoprotein fractions. This was due to an increase of the serum β-lipoprotein fraction while the α-lipoprotein fraction was not changed significantly (group A) or decreased (group B). Serum cholesterol or triglycerides tended to be increased, but mean changes were often not significant.
3. The observed alterations in serum lipoproteins are consistent with the possibility of an increased risk for coronary heart disease which could offset partly the beneficial effects of a lowered blood pressure in diuretic-treated patients with hypertension.
Effects of Prazosin on Blood Pressure and Plasma Renin Activity in Man
Authors: Rosenthal J. , Jaeger H. , Arlart I. 
Published: August 2015

1. The effects of oral administration of 4·5 mg of prazosin/day on blood pressure and on plasma renin activity were assessed in patients with essential hypertension and in healthy normotensive volunteer subjects.
2. Mean blood pressure in the hypertensive group fell significantly within 2 weeks of treatment, whereas heart rate was little affected. None of the parameters measured in the normotensive subjects during treatment with prazosin revealed significant changes.
3. Sub-classification of the hypertensive patients into low-, normal- and high-renin categories revealed significant decreases of renin in all six patients with high renin- and in four out of 12 patients with normal renin- but not in the two patients with low renin-essential hypertension.
4. The results indicate that prazosin exerts its hypotensive action and suppresses plasma renin activity particularly in patients with high renin-essential hypertension. These may be considered to have increased sympathetic drive.
5. Conceivably, the blood pressure-lowering effect of prazosin is effected by peripheral vasodilatation and also by a decreased venous return to the heart.
The Hypertension Register of the North Karelia Project
Authors: Nissinen A. , Tuomilehto J. , Puska P. 
Published: August 2015

1. One major subprogramme of the North Karelia Project was the hypertension programme which aimed at lowering of the high blood pressure among the whole population, and especially among middle-aged men. The hypertension programme consisted of intervention integrated with the existing health care structure of the county of North Karelia.
2. The hypertension register, which was the major tool of the programme, aimed to maintain patients in treatment and to get information about the development of the programme. Registration of hypertensive subjects was continuous between 1972 and 1977 and registered patients had annual follow-up examinations.
3. After 5 years of the programme, there were approximately 17 000 registered patients which is 9·7% of the total population.
4. Proportion of drop-outs at the annual follow-up examinations was less than 10%. 83% of the registered hypertensive subjects were under drug treatment after 3 years intervention. The percentage of normotensive subjects increased significantly year by year.
5. Preliminary results from the stroke register of the North Karelia Project indicate that the incidence of stroke decreased as hypertension control was improved.
Familial Hypertension and Hormonal Profile, Renal Haemodynamics and Body Fluids of Young Normotensive Subjects
Authors: Bianchi G. , Picotti G. B. , Bracchi G. , Cusi D. , Gatti M. , Lupi G. P. , Ferrari P. , Barlassina C. , Colombo G. , Gori D. 
Published: August 2015

1. Almost all the factors that may cause a rise in blood pressure are, in turn, influenced by the increase in blood pressure per se. Thus any primary involvement of one or more of these factors in the pathogenesis of essential hypertension must be evaluated before or during the development of hypertension.
2. Young normotensive subjects both of whose parents are hypertensive have a much higher probability of developing hypertension than those whose parents are both normotensive.
3. The following measurements were made in 56 subjects of the first group (both parents hypertensive) and 35 of the second group (both parents normotensive), matched for age, sex and body surface area: renal plasma flow and glomerular filtration rate, using p-aminohippurate and inulin clearance; 24 h urinary excretion of aldosterone, protein and electrolytes; plasma renin activity; plasma volume. Plasma catecholamines and cardiac index were also measured in 26 subjects of the first group and 25 subjects of the second group using a radioenzymic method and echocardiography.
4. All these factors were similar in the two groups except that renal plasma flow was higher in the first group (767·2 ± 30 versus 650·7 ± 17 ml/min, P < 0·01). Plasma renin activity tended to be lower in subjects with a higher renal plasma flow, but there was no significant negative correlation between the two factors.
5. The possibility that the higher renal plasma flow in subjects with a high probability of developing hypertension is a compensatory mechanism for a primary intrarenal defect is discussed.
Are Racial Differences in Essential Hypertension Due to Different Pathogenetic Mechanisms?
Authors: Sever P. S. , Peart W. S. , Meade T. W. , Davies I. B. , Gordon D. , Tunbridge R. D. G. 
Published: August 2015

1. Plasma noradrenaline concentration and plasma renin activity were measured in a control, British, urban population (n = 115) in which blacks were matched for age and sex with whites.
2. Similar measurements were made in subjects with essential hypertension (77 white and 23 black), and 48 healthy normotensive white civil servants.
3. In controls blood pressure was significantly higher in blacks; it correlated with age in both races and with pulse rate in blacks. There were no significant racial differences in plasma noradrenaline which was positively correlated with age in both blacks and whites. Mean plasma renin activity was 55% lower in blacks, and this difference was not related to urinary sodium excretion.
4. In hypertensive subjects plasma noradrenaline positively correlated with age in blacks. This relationship was not found in whites in whom 20% of young hypertensive subjects (<45 years) had significantly raised plasma noradrenaline. Plasma renin activity was again significantly lower in blacks. In white hypertensives plasma noradrenaline and renin activity were significantly correlated.
5. There may be racial differences in the pathogenesis of essential hypertension.
Kinetics of Mucosal Influx of Glycylsarcosine, Glycine and Leucine into Hamster Jejunum and Ileum in Vitro
Authors: Schedl H. P. , Burston D. , Taylor E. , Matthews D. M. 
Published: August 2015

1. This paper describes an investigation of the kinetics of influx of the dipeptide glycylsarcosine and the amino acids glycine and l-leucine into rings of everted hamster small intestine in vitro, in proximal and distal small intestine (jejunum and ileum). Results were expressed per unit wet weight of intestine.
2. At all concentrations studied (0·1–100 mmol/l), influx of glycylsarcosine was more rapid in the jejunum than in the ileum. In contrast, at all concentrations studied, influx of glycine and leucine was more rapid in the ileum than the jejunum.
3. Estimates of the simple diffusion component in total influx were made. This component became increasingly large as the substrate concentration was raised. After correction for simple diffusion, transport of all three substrates conformed to Michaelis-Menten kinetics in both jejunum and ileum. Values for simple diffusion, apparent Kt and Vmax. are reported.
4. Possibly physiological implications of the results are discussed, and it is pointed out that under experimental conditions similar to our own, simple diffusion is too large a component in total influx to be ignored.
Arterial Wall Renin and Renal Venous Renin in the Hypertensive Rat
Authors: Garst Josephine B. , Koletsky S. , Wisenbaugh P. E. , Hadady Magdalena , Matthews D. 
Published: August 2015

1. Infusion of sufficient renin to raise the blood pressure of normal rats to hypertensive levels resulted in increased renin in the arterial wall.
2. Arterial wall renin and renal venous renin were normal in younger spontaneously hypertensive rats, but in older spontaneously hypertensive rats arterial wall renin was significantly increased and renal venous renin was significantly decreased.
3. Arterial wall renin in rats with either acute or chronic two-kidney Goldblatt renal hypertension was significantly increased, whereas circulatory renin was elevated in the former, but depressed in the latter.
4. Arterial wall renin may play a role in the maintenance of acute and chronic renal hypertension and also perhaps of spontaneous hypertension of long duration in older rats.
Binding of Human Serum Ferritin to Concanavalin A
Authors: Worwood M. , Cragg S. J. , Wagstaff M. , Jacobs A. 
Published: August 2015

1. A high proportion of the ferritin in normal serum binds to concanavalin A. Binding is prevented by the addition of α-d-methylglucoside to the reaction mixture.
2. Ferritin in extracts of normal heart, liver and spleen or serum ferritin from patients with massive hepatic necrosis does not bind to concanavalin A.
3. Isoelectric focusing of preparations of serum ferritin from patients with primary haemochromatosis shows that the ferritin fraction binding to concanavalin A consists, predominantly, of the more acidic isoferritins.
4. These findings suggest that carbohydrate residues may be added to ferritin during its secretion into the plasma. Glycosylation may account for the heterogeneity of serum ferritin on isoelectric focusing.
5. Direct release of intracellular ferritin from damaged tissue may be indicated by an increase in the proportion of circulating ferritin which does not bind to concanavalin A. Such an increase has been found in sera from patients with iron overload.
Structural and Functional Alterations in the Mucosa of Self-Filling Intestinal Blind Loops in Rats
Authors: Menge H. , Köhn R. , Dietermann K.-H. , Lorenz-Meyer H. , Riecken E. O. , Robinson J. W. L. 
Published: August 2015

1. Self-filling blind loops of jejunum were constructed in three groups of rats; in the first, blind loops were created without further manipulation; in the second the bile was diverted permanently into the lower ileum below the blind loop, whereas in a third neomycin was added to the drinking water throughout the experiment. Two weeks after the creation of the blind loops, they were used for structural and functional studies.
2. Morphometric and microdissection techniques demonstrated that the surface area of the individual villi of the mucosa of ‘ordinary’ blind loops had increased fourfold in comparison with corresponding control jejunum, whereas the increase was only twofold in rats with bile diversion or in the series treated with neomycin. There were proportional increases in crypt length and mitotic activity of the crypts in all three series, which suggest that the alterations in the mucosa were due to hyperplasia in both villus and crypt compartments.
3. Sucrase, succinate dehydrogenase, alkaline phosphatase and non-specific esterase activities, determined biochemically or histochemically, were reduced in the mucosae of all blind loops, though the changes were most pronounced in the ‘ordinary’ blind loops. The accumulation of l-phenylalanine by mucosal slices in vitro was depressed, although the decrease was less marked in the series treated with neomycin.
4. These results suggest that both bacteria and deconjugated bile acids play a role in the development of the hyperplastic changes of the blind-loop mucosa, but that another factor might also be involved: as a possible candidate, stasis of the intestinal contents was considered.
5. To test this hypothesis, loops of rat colon were transposed into the jejunum. Above the transposed loop, the jejunal mucosa developed hyperplasia of both villus and crypt compartments, with a reduction in its ability to accumulate l-phenylalanine. It is argued that these changes, probably caused by stasis of the intestinal contents, are triggered off by the dilatation of the gut, which may also be implicated in the mucosal alterations in blind loops.
Carbohydrate-Containing Materials in Urine from Normal and Diabetic Subjects
Authors: Clamp J. R. , Hartog M. , Shelley J. H. 
Published: August 2015

1. Abnormalities in glycoprotein metabolism are believed to play a role in diabetic microangiopathy. We have therefore measured the urinary excretion of carbohydrate-containing materials in normal and diabetic subjects.
2. Diabetic subjects were found to excrete excessive quantities of such material, which may parallel the increases observed in plasma and structural glycoproteins found in previous studies.
3. Systemic administration of a synthetic derivative of vasicine, which is known to affect mucus glycoprotein, was shown to restore these elevated urinary concentrations seen in diabetic subjects to values close to normal, but this drug had no significant effect on urinary concentrations of such materials in normal subjects.
Diuretics, Hepatic and Thoracic Duct Lymph Flows in the Dog
Authors: Szwed J. J. , Maxwell D. R. 
Published: August 2015

1. Simultaneous thoracic duct and hepatic lymph flows were measured in 29 mongrel dogs before and after the intravenous administration of mannitol, ethacrynic acid, frusemide and chlorothiazide in separate experiments.
2. Thoracic duct lymph flow increased significantly after each diuretic agent was administered.
3. Hepatic lymph flow increased only after ethacrynic acid and mannitol administration. Frusemide and chlorothiazide did not alter hepatic lymph flow.
4. These data show that increases in thoracic duct lymph flow after ethacrynic acid and mannitol arise partly from the liver, as well as from other organs.
Plasma Renin Activity in Diabetes Mellitus
Authors: Burden A. C. , Thurston H. 
Published: August 2015

1. The plasma renin activity (PRA) was measured in 76 diabetic patients who were attending an outpatients clinic. Of these patients 16 had untreated hypertension and 28 had diabetic complications, which ranged from microaneurysms to renal failure and blindness.
2. Compared with age- and sex-matched normotensive control subjects, both normotensive and hypertensive diabetic patients had significantly higher PRA (P &lt; 0·001).
3. Hypertensive diabetic patients also showed a higher PRA than matched hypertensive control subjects (P &lt; 0·005). There were no significant differences between diabetic patients with hypertension or complications compared with those without these features.
4. Although this elevation of PRA could be due to a change in another component of the renin—angiotensin system, hypersecretion of renin is the most likely explanation.
Sites of Clearance of Leucocyte Pyrogen in the Rabbit
Authors: Townsend Yvonne , Cranston W. I. 
Published: August 2015

1. The dose—response curve for sustained infusions of leucocyte pyrogen has been demonstrated, and an optimum dose indicated for leucocyte pyrogen clearance experiments.
2. The lungs, liver and small bowel are not significantly involved in removal of leucocyte pyrogen from the circulation in conscious rabbits.
3. A single circulation through one kidney removes up to half of the infused dose of leucocyte pyrogen.