bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evidence for Postjunctional Vascular α2-Adrenoceptors in Peripheral Vascular Regulation in Man
Authors: Elliott H. L. , Reid J. L. 
Published: August 2015

1. Preliminary studies in healthy normotensive subjects with a selective α2−adrenoceptor antagonist 2 − {2 − (1,4 − benzodioxanyl)} − 2 − imidazoline (RX781094) in a dose of 0.2 μg/kg intravenously are described.
2. There was a transient increase in blood pressure, and plasma noradrenaline, 10–20 min after dosing and an associated reduction in heart rate. These observations are consistent with blockade of peripheral presynaptic α2−adrenoceptors in man.
3. The pressor responses to α−methylnoradrenaline, which has relatively selective agonist effects on α2−adrenoceptors, were markedly attenuated between 0.5 and 3.0 h after dosing (dose ratio &gt; 20).
4. The pressor responsiveness to intravenous phenylephrine, a selective α1−adrenoceptor agonist, was only slightly reduced (dose ratio 1.7 ±0.8), as was the blood pressure rise after intravenous noradrenaline (dose ratio 1.7 ± 0.7).
5. The differential effects on the agonist pressor responses are consistent with antagonism by RX781094 of post−junctional α2−adrenoceptors on vascular smooth muscle.
Role of Vasoconstrictor Systems in Experimental Glucocorticoid-Hypertension in Rats
Authors: Waeber Bernard , Gavras Haralambos , Bresnahan Margaret R. , Gavras Irene , Brunner H. R. 
Published: August 2015

1. The blood pressure effect of SKF 64139, a phenylethanolamine N-methyltransferase (PNMT) inhibitor acting both in the central and peripheral nervous system, was studied in conscious normotensive and glucocorticoid-hypertensive rats maintained for 2 weeks on a salt-deficient diet. On the day of the experiment, mean blood pressure was 119.2 ± 1.1 mmHg (mean ± sem) in the normotensive and 143.2 ± 1.9 mmHg (P &lt; 0.001) in the hypertensive rats. In all animals, the blood pressure was followed for 4 h after oral gavage by either SKF 64139 (50 mg/kg) or its vehicle (5% glucose solution).
2. In the vehicle-treated rats, no change in blood pressure occurred. However, after SKF 64139 administration, a 17.9 ± 3.8 mmHg (P &lt; 0.001) blood pressure fall was observed in the hypertensive rats whereas normotensive animals did not decrease their pressure.
3. Plasma catecholamines were determined in all these rats at the end of the observation period. No significant difference in plasma noradrenaline and adrenaline levels was observed between normotensive and hypertensive as well as vehicle- and SKF 64139-treated rats, though both catecholamines tended to be higher after administration of the PNMT inhibitor.
4. In two additional groups of glucocorticoid-hypertensive rats, the blood pressure effects of an infusion of saralasin, a competitive antagonist of angiotensin II, or of a bolus injection of a vasopressin analogue antagonizing the pressor action of vasopressin, were investigated over a 20 min period.
The vasopressin antagonist had no blood pressure effect whereas saralasin decreased mean blood pressure from 144 ±1.9 to 136 ± 3.2 mmHg (P &lt; 0.005).
5. These data suggest that the sympathetic nervous system is the main vasoconstrictor system involved in the maintenance of established glucocorticoid hypertension. Since SKF 64139 is also known to inhibit to some degree α-adrenoceptors, monoamine oxidase and neuronal uptake processes, it remains unclear, however, whether the blood pressure-lowering effect of this PNMT inhibitor can be attributed to central blockade of adrenaline synthesis.
Detection of Morquio a Syndrome Using Radiolabelled Substrates Derived from Keratan Sulphate for the Estimation of Galactose 6-Sulphate Sulphatase
Authors: Hopwood John J. , Elliott Helen 
Published: August 2015

1. The following radiolabelled disaccharide and tetrasaccharide were prepared from keratan sulphate and evaluated as substrates for galactose 6-sulphate sulphatase present in cultured human skin fibroblasts: O-(β-d-6-sulphogalactosyl)−(1 → 4)−2,5-anhydro-d-[1-3H] mannitol 6-sulphate (Gal6S-anM6S) and the tetrasaccharide equivalent Gal6S-GlcNAc6S-Gal6S-anM6S. Radiolabelled trisaccharide substrates, N-acetylgalactosamine 6-sulphate (β, 1 → 4)-glucuronic acid-(β 1→3)-N-acetyl[l-3H]galactosaminitol 6-sulphate (GalNAc6S-GlcA-GalitolNAc6S), and N-acetylgalactosamine 6-sulphate (β, 1 → 4)-glucose-(β, 1 → 3)-N-acetyl-[1-3H]galactosaminitol 6-sulphate (GalNAc6S-GlcGalitol-NAc6S), were prepared from chondroitin 6-sulphate and used to assay N-acetylgalactosamine 6-sulphate sulphatase.
2. Sulphatase activity obtained with Gal6S-anM6S was approximately the same, 100 and 30–50 times less than values obtained with Gal6S-GlcNAc6S-Gal6S-anM6S, GalNAc6S-GlcA-Galitol-NAc6S and GalNAc6S-Glc-GalitolNAc respectively. Less than 5% of normal activity resulted when these substrates were incubated with fibroblasts from Morquio A patients. These results demonstrate that the trisaccharide substrates derived from chondroitin 6-sulphate although de-O-sulphated at a considerably higher rate than was observed for the de-O-sulphation of the disaccharide and tetrasaccharide derived from keratan sulphate, are acted upon by the same sulphatase.
3. Galactose 6-sulphate sulphatase activity in fibroblast homogenates assayed with Gal6S-anM6S as substrate clearly distinguished Morquio A patients from normal controls, and Morquio B and Sanfilippo D patients.
4. We recommend the use of both the radiolabelled disaccharide derived from keratan sulphate and the trisaccharide derived from chondroitin 6-sulphate to assess sulphatase activity in fibroblasts of atypical Morquio patients.
Kinetics of Proliferation of Rat Aortic Smooth Muscle Cells in Goldblatt One-Kidney, one-Clip Hypertension
Authors: Carlier P. G. , Rorive G. , Barbason H. 
Published: August 2015

1. Wistar female rats were made hypertensive by applying a silver clip to the left renal artery and removing the right kidney. In aortas, the proliferation fraction of smooth muscle cells, DNA synthesis and wet weight have been correlated with the blood pressure increase subsequent to the operation.
2. A wave of proliferation of smooth muscle cells in the aortic media is triggered immediately after the highest increased rate of blood pressure. When blood pressure stabilizes at high values, the metabolism of nucleic acid within the aortic media resumes its normal level but the arterial changes previously established persist.
3. The sequence of pathological events responsible for these changes could be: increment of blood pressure; increase in wall stress; proliferation of smooth muscle cells; thickening of arterial wall; correction of the wall stress; end of proliferation.
4. The consequence of this early proliferation of aortic smooth muscle cells is not clear but it is probably one of the mechanisms through which high blood pressure is sustained. It can also participate in atherogenesis, being in this way one of the bases of the well-known relationship between hypertension and atherosclerosis.
Decreased Liver δ-Aminolaevulinate Dehydratase Activity in Porphyria Cutanea Tarda and in Alcoholism
Authors: Kondo Masao , Urata Gumpei , Shimizu Yoshitaka 
Published: August 2015

1. δ-Aminolaevulinate dehydratase activity was measured in liver biopsy specimens from 13 patients with porphyria cutanea tarda, 13 alcoholics and 10 control subjects.
2. The mean enzyme activities in liver of porphyria cutanea tarda and alcoholics were 34% (P &lt; 0.001) and 49% (P &lt; 0.001) respectively of the control level.
3. Heat treatment of liver supernatant caused slight inhibition of the enzyme activity in porphyria cutanea tarda and in controls.
4. Addition of Zn2+ to liver supernatants slightly increased the enzyme activity in both porphyria cutanea tarda and controls.
5. The addition of liver supernatant from the porphyria cutanea tarda to purified bovine 6–aminolaevulinate dehydratase did not result in suppression of the enzyme activity.
6. The apparent Km value of δ-aminolaevulinate dehydratase was 4.3 × 10–4 mol/l for porphyria cutanea tarda livers and 3.3 × 10–4 mol/l for control livers. The difference between the two was not significant.
Renal Function in Pregnancy
Authors: Atherton J. C. , Green R. 
Published: August 2015

Although our understanding of many renal mechanisms has been advancing rapidly over the past few years, there is still a dearth of information about changes that occur in renal function during pregnancy — surely one of the greatest physiological disturbances possible. It is difficult in many instances to find a description of the changes that occur quite apart from the underlying alterations in mechanisms that are responsible for them.
Part of the difficulty has arisen because of the ethical and methodological problems that arise when women are used as ‘experimental animals’ until recently there has not been a suitably documented animal model, though whether this was because of technical difficulties or lack of interest on the part of investigators is not known. Recently, however, it has become apparent that many changes in renal function in the rat are similar to those occurring in women and some aspects of renal function in the rat have been investigated in detail. Since not all aspects of renal function can be covered in this review we shall concentrate on three of the more important areas, namely haemodynamics, sodium and water handling and glucose excretion, and discuss how these are changed during pregnancy; comments on the possible mechanisms involved in these changes are presented where appropriate.
The Assessment of Nocturnal Oxygen Saturation
Authors: Meanock C. I. , Guyatt A. R. , Cumming G. 
Published: August 2015

1. Existing methods of assessing nocturnal episodic hypoxaemia are either insensitive or ignore the majority of the available data.
2. We describe a method of analysis using offline digital processing. A distribution of oxygen saturation (Sao2) with time is produced from all the available data, and subjected to moment analysis to produce a simple index which describes an entire night's Sao2.
3. Our results suggest that the mean and the coefficient of skew fully described a night's Sao2. However, in subjects with chronic air-flow obstruction, the third moment about 100% oxygen saturation (M3100), a single figure, has the same descriptive power as mean and skew.
4. In 17 subjects with chronic air-flow obstruction a significant correlation was found between both daytime Sao2 and Paco2 when plotted against either the M3100 or the skew.
5. Measurements made on two occasions in seven subjects showed good reproducibility for the skew and M3100 indices.
Effect of Hypoxia and Hypercapnic Acidosis on Renal Autoregulation in the Dog: Role of Renal Nerves
Authors: Anderson Robert J. , Pluss Richard G. , Pluss William T. , Bell Jon , Zerbe Gary G. 
Published: August 2015

1. Previous studies suggest that hypoxia and hypercapnic acidosis exert a renal nerve mediated adverse effect on renal haemodynamic function. We therefore examined the effect of hypoxia and hypercapnic acidosis on renal blood flow and glomerular filtration rate responses to lowering renal perfusion pressure from 125 to 75 mmHg in the anaesthetized dog. To study the role of renal nerves in these responses, paired innervated and denervated kidneys were studied in each animal.
2. Hypoxia (Po2 43 ± 3 mmHg) affected neither renal blood flow nor glomerular filtration rate responses to decreasing renal perfusion pressure.
3. Hypercapnic acidosis (Pco2 71 ±2 mmHg; pH 7.03 ± 0.01) significantly decreased both renal blood flow and glomerular filtration rate as renal perfusion pressure was lowered. This effect of hypercapnic acidosis could be abolished by renal denervation.
4. These findings suggest that hypercapnic acidosis results in renal nerve stimulation, which prevents the usual decrease in renal afferent arteriolar tone that occurs in response to lowering of renal perfusion pressure.
Serum Amyloid a Levels in Human Renal Allograft Rejection
Authors: Maury C. P. J. , Teppo A. M. , Eklund B. , Häyry P. , Ahonen J. 
Published: August 2015

1. Serum amyloid A (SAA) levels were studied in 35 recipients of cadaveric renal transplants. Marked SAA elevations were seen during all acute allograft rejection episodes. The mean peak SAA level in well-documented rejections was 446 mg/l (median 415 mg/l, range 132–1040 mg/l; controls &lt; 1 mg/l).
2. Rejections in patients receiving cyclosporin-A alone as post-transplantation immunosuppressive medication were characterized by a significantly higher peak SAA level than rejections in patients receiving cyclosporin-A in combination with methylprednisolone (539 ± 53 mg/l, mean ± sem, vs 226 ± 9 mg/l, P &lt; 0.01).
3. Excluding surgery-induced SAA elevations in the immediate postoperative period, seven significant SAA peaks not related to allograft rejection were observed. These were associated with surgical complications and infections, and in one case probably with the underlying rheumatic disease, which was complicated by amyloidosis.
4. The results show that acute renal allograft rejection induces a dramatic acute phase SAA response. Since SAA is an easily measured serum component and the rejection-induced elevation is an early event, monitoring of SAA in kidney transplant patients-5-have considerable clinical significance.
Proteins of the Kidney Microvillar Membrane; Analysis by Sodium Dodecyl Sulphate-Polyacrylamide Gel Electrophoresis and Crossed Immunoelectrophoresis
Authors: Abbs Michael T. , Kenny A. John 
Published: August 2015

1. A microvillar fraction was prepared from human kidney cortex. This fraction was seven to 10 times enriched in aminopeptidases N and A, γ-glutamyltransferase, dipeptidyl peptidase IV, neutral endopeptidase and alkaline phosphatase.
2. Dipeptidyl peptidase IV activity of human renal microvilli could be inhibited by di-isopropylphosphorofluoridate and neutral endopeptidase activity by phosphoramidon.
3. Nearly all the activity of aminopeptidases A and N could be removed from the membrane by treatment with papain, but only 19% and 33% of dipeptidyl peptidase IV and γ-glutamyltransferase activities were released under the same conditions. Neutral endopeptidase and alkaline phosphatase were not solubilized by papain. Treatment with elastase gave results similar to papain, except that γ-glutamyltransferase was not released.
4. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis under reducing conditions of microvilli revealed 36 polypeptide bands, 12 of which contained carbohydrate. A band of apparent Mr 130 000 was labelled with [3H]di-isopropylphosphorofluoridate and hence identified as dipeptidyl peptidase IV.
5. Antibodies raised to human kidney microvilli produced 11 precipitates with detergent solubilized proteins and six with papain released proteins. Several of the precipitates were identified histochemically.
6. Microvilli prepared from human kidney are very similar to microvilli from pig and rabbit kidney with respect to enzymology, response to papain treatment, sodium dodecyl sulphate-polyacrylamide gel patterns and immunochemistry.
Allogeneic Kidney Transplantation after Active Immunological Enhancement: A Model to Study Post-Transplantation Hypertension in Rats
Authors: De Keijzer M. H. , Provoost A. P. , Van Aken M. , Weyma I. M. , Kort W. J. , Wolff E. D. , Molenaar J. C. 
Published: August 2015

1. A model was developed to study post-transplant hypertension after allogeneic kidney transplantation between two inbred normotensive rat strains. Prolongation of graft survival was achieved by ‘active immunological enhancement’.
2. Renal function, systolic blood pressure and plasma renin concentration were determined.
3. The systolic blood pressure started to rise in the second week after allogeneic transplantation. The glomerular filtration rate was impaired to a greater extent than the effective renal plasma flow.
4. Histopathological changes occurred indicating immunological reactions in the renal graft.
5. The plasma renin concentration was lower in transplant recipients than in controls.
6. We hypothesize that retention of sodium is mediately involved in the post-transplant hypertension observed in this model.
Effects of Smoking on Oral Fat Tolerance and High Density Lipoprotein Cholesterol
Authors: Elkeles R. S. , Khan S. R. , Chowdhury V. , Swallow M. B. 
Published: August 2015

1. Changes in serum triglyceride and high density lipoprotein (HDL) cholesterol after a fatty meal have been studied in smokers and non-smokers.
2. Average serum triglyceride during the study was higher in smokers than in non-smokers.
3. In non-smokers there was a rise in the HDL2/HDL3 cholesterol ratio after oral fat, but not in smokers.
4. These findings are compatible with the hypothesis that smoking interferes with the lipolysis of triglyceride rich lipoproteins and the conversion of HDL3 into HDL2.
Vascular Angiotensin-Converting Enzyme Activity in Man and other Species
Authors: Miyazaki Mizuo , Okunishi Hideki , Nishimura Kazuo , Toda Noboru 
Published: August 2015

1. Angiotensin-converting enzyme (ACE) activity in blood vessels of different species was determined.
2. ACE was solubilized by Nonidet P-40, and assayed by reversible phase high performance liquid chromatography. Approximately 98% ACE was recovered in the liquid phase by the use of the detergent.
3. The ACE activity varied with chloride ion (Cl−) concentrations; the maximum activities in dog, human, monkey and rabbit tissues were obtained at the concentrations of 800, 600, 600 and 300 mmol/l respectively. The optimal Cl− concentration was quite similar in different tissues and plasma obtained from the same species.
4. The ACE activity in the cerebral, mesenteric, pulmonary and renal arteries was in a range between 1.01 and 1.60 m-units/mg of protein in dogs and between 0.43 and 0.94 m-unit/mg of protein in monkeys. The activity in dog aortae was 0.20 ± 0.02 m-unit/mg of protein, and the activity in aortic endothelial cells was 2.61 ± 0.65 m-units/mg of protein. ACE activities in the dog lung, kidney cortex and cerebral cortex were 28.6 ± 2.6, 15.7 ± 3.0 and 3.5 ± 0.6m-units/mg of protein respectively. SA-446, a captopril-like ACE inhibitor, reduced the ACE activity in arteries in a dose-dependent manner.
5. Vascular ACE appears to be concentrated in the endothelium and may contribute to regulate vascular muscle tone and local blood flow by a conversion of angiotensin I into II.
The Relationship between Oxygen Delivery and Consumption in the Conscious Rat before and after Expansion of Body Fluid Volumes
Authors: Ledingham J. M. , Gofford S. , Evans S. J. W. 
Published: August 2015

1. Oxygen consumption and delivery (defined as the product of cardiac output, haemoglobin concentration and arterial oxygen saturation) and haemodynamic variables were examined in the conscious resting rat throughout the day and after the expansion of body fluid volumes. Cardiac output was measured in arbitrary units by electromagnetic flowmetry and oxygen consumption by respirometry.
2. The variability of blood pressure in the basal state was significantly less than that of cardiac output.
3. Oxygen consumption was significantly correlated with cardiac output and oxygen delivery.
4. In studies undertaken throughout the day, both oxygen consumption and delivery fell in the afternoon and there was evidence that the relationship between these two variables was curvi- rather than recti-linear.
5. During oral sodium chloride administration for 7 days, blood pressure rose and some evidence was found for an alteration in the relationship between oxygen consumption and delivery, with an excess of delivery relative to consumption, particularly on the first day of salt loading.
6. Intravenous injection of sodium chloride solution (0.171 mol/l) did not alter the relationship between oxygen consumption and delivery.
7. Expansion of blood volume, while the packed cell volume was maintained nearly constant, raised oxygen delivery transiently and evidence was obtained that the relationship between oxygen consumption and delivery was altered, with oxygen delivery rising relatively more than oxygen consumption.
8. The findings are discussed in relation to the autoregulatory hypothesis of circulatory control and for the role of autoregulation in hypertensive states. The importance of relating oxygen delivery to metabolic requirements in studies of the role of autoregulation is emphasized.
The Antihypertensive Effect of Dietary Potassium Chloride Loading in Rats with Adrenal Regeneration Hypertension
Authors: Milmer K. E. , Bennett T. , Gardiner S. M. 
Published: August 2015

1. Adrenal regeneration hypertension was induced in male Wistar rats by unilateral adrenal enucleation, contralateral adrenalectomy and the provision of a 1% (w/v) NaCl solution for drinking.
2. A fivefold increase in dietary KCl content caused a significant reduction in the systolic blood pressure of hypertensive rats but not of control rats.
3. During the increase in potassium intake there was a marked polydipsia. When 1% NaCl solution was the drinking fluid, the resultant increase in sodium intake was associated with an abolition of the antihypertensive effect of potassium loading, but when the sodium intake was held constant, the antihypertensive effect was maintained.
4. In rats with adrenal regeneration hypertension, plasma volume was significantly higher, and packed cell volume and plasma protein concentrations were significantly lower than in control rats. These differences were abolished after 4 days of dietary KCl supplementation.
5. Increased dietary potassium intake was associated with significantly lower serum aldosterone concentrations and significantly higher plasma potassium concentrations in adrenal enucleated rats compared with controls.
6. The possibility that a reduction in extracellular fluid volume (due to a natriuresis) and/or a peripheral vasodilatation contributed to the antihypertensive effect of KCl loading is discussed.
The Influence of Acute Starvation on the Cardiovascular Responses to Lower Body Subatmospheric Pressure or to Standing in Man
Authors: Bennett T. , MacDonald I. A. , Sainsbury R. 
Published: August 2015

1. The cardiovascular responses to lower body subatmospheric pressure or to standing were measured in the same nine normal male subjects after a 12 h and after a 48 h fast.
2. After the 48 h fast there was a significant reduction in diastolic blood pressure and forearm vascular resistance (relative to the values after a 12 h fast) when subjects were supine.
3. During exposure to lower body subatmospheric pressure, subjects who had fasted for 48 h showed an inability to maintain systolic blood pressure, accompanied by an impairment of forearm vasoconstriction and an exaggerated tachycardia (relative to their responses after a 12 h fast). Similar disorders of cardiovascular homoeostasis were seen on standing.
4. The results are consistent with an inhibition of sympathetic nervous activity after a 48 h fast, but other possibilities are discussed.