bluuebunny/crossref_metadata_2025 huggingface dataset:
Alterations of Adrenal and Uterine Angiotensin II Receptors during Variation of Sodium Intake and/or Experimental Hypertension
Authors: Devynck M. A. , Pernollet M. G. , MacDonald G. J. , Matthews P. G. , Raisman R. S. , Meyer P.
Published: August 2015

1. Angiotensin II receptors from rat adrenal gland and myometrium were studied during variation of sodium intake.

2. In both target-tissues low Na+ diet increased the number of receptors whereas a high Na+ diet did not modify the adrenocortical receptors but increased the number of uterine receptors.

3. Deoxycorticosterone and one kidney Goldblatt hypertension were associated with a decrease in the number of adrenal receptors.

4. Alterations of angiotensin II receptors alone cannot explain satisfactorily the variations of sensitivity of target-cells to angiotensin II during sodium balance changes.
Renal Prostaglandin Production in the Japanese (Kyoto) Spontaneously Hypertensive Rat
Authors: Dunn Michael J.
Published: August 2015

1. Renal venous and urinary prostaglandin E2 (PGE2) and prostaglandin F2α (PGF2α) were measured in spontaneously hypertensive (SH) rats and Wistar-Kyoto normotensive rats (WKy) of 4 different ages, ranging from 4 to 54 weeks.

2. Renal venous (plasma) PGE2 and PGF2α were similar in WKy and SH rats at all ages, except for greater PGF2α in 40–54 week old SH rats.

3. Urinary (24 h) PGE2 and PGF2α were similar in WKy and SH rats at all ages, except for greater PGE2 in 7–12 week old SH rats.

4. There was a significant trend for renal venous and urinary PGE2 and PGF2α to decrease with advancing age.

5. These experiments did not show evidence that the SH rat kidney, in vivo, has an abnormality of PGE2 or PGF2α production or degradation, which alters secretion or excretion of either prostaglandin.
Effects of Indomethacin Alone and during Diuretic or β-Adrenoreceptor-Blockade Therapy on Blood Pressure and the Renin System in Essential Hypertension
Authors: Lopez-Ovejero J. A. , Weber M. A. , Drayer J. I. M. , Sealey J. E. , Laragh J. H.
Published: August 2015

1. Indomethacin was administered alone or in addition to either diuretic or propranolol therapy to three groups of patients with essential hypertension on a free sodium diet.

2. Indomethacin administration reduced renin secretion by about 30% in untreated uncomplicated hypertensive patients and by about 75% in those whose renin secretion had either been stimulated or suppressed by maintained diuretic or β-adrenoreceptor-blockade therapy.

3. Indomethacin administration produced no net effect on blood pressure in untreated patients with uncomplicated hypertension but it blunted or reversed the antihypertensive effect of either diuretic or propranolol therapy.

4. Salt and water retention may be an important factor in the blood pressure-raising effect of indomethacin during diuretic or propranolol therapy: In addition, prostaglandin synthesis may be important in counteracting increased α-adrenergic tone, which may limit the blood pressure-lowering effect of β-adrenoreceptor-blockade.

5. Because of these interactions and their pressor potential indomethacin should be used with caution when combined with either diuretics or β-adrenoreceptor blockers.
Central Nervous System Pressor Responses in Rats Susceptible and Resistant to Sodium Chloride Hypertension
Authors: Ikeda T. , Tobian L. , Iwai J. , Goossens Patricia
Published: August 2015

1. The pressor responses to hypertonic saline and angiotensin II introduced into the left lateral ventricle were both significantly greater in salt-sensitive (S) rats compared with salt-resistant (R) rats, with all rats on a low Na diet.

2. When S rats were given thiazide to nullify the pressor effect of dietary NaCl, their blood pressure averaged only 5 mmHg higher than that of the R rats; nevertheless, these S rats had significantly higher central nervous system pressor responses to angiotensin II and hypertonic saline.

3. Thus, if excessive dietary Na increases blood pressure by way of action on the central nervous system, these heightened pressor responses could partially account for the NaCl hypertension in S rats. Alternatively, depressed central nervous system pressor responses in R rats could partially explain the resistance of R rats to NaCl hypertension.
Sodium and Renin in the Hypertension of Early Renal Disease
Authors: Wong S. F. , Mitchell M. I. , Robson V. , Wilkinson R.
Published: August 2015

1. Plasma renin activity, response to saralasin and exchangeable sodium have been measured in 43 patients with early renal disease.

2. Blood pressure was directly proportional to plasma renin activity. However, mean plasma renin activity was lower in patients with renal disease than in normal controls.

3. Blood pressure fell in response to saralasin infusion in proportion to the pre-infusion plasma renin activity.

4. Exchangeable sodium in hypertensive patients with renal disease did not exceed that in normotensive patients in contrast to earlier reports. Discrepancies may arise from the difficulty in interpreting measured exchangeable sodium in relation to body build.
Sympathetic and Parasympathetic Components of Reflex Cardiostimulation during Vasodilator Treatment of Hypertension
Authors: in 't Veld A. J. Man , Wenting G. J. , Verhoeven R. P. , Schalekamp M. A. D. H.
Published: August 2015

1. Haemodynamic responses to diazoxide (300 mg intravenously) were studied in 15 hypertensive patients before and after chronic β-adrenoreceptor blockade by 320 mg of propranolol daily. After diazoxide alone, mean arterial pressure and total peripheral resistance were lowered by 24 ± 3 and 35 ± 5% (mean ± sem) respectively. Cardiac output and heart rate rose by 25 ± 9 and 21 ± 3%. During β-adrenoreceptor blockade, the percentage changes of mean arterial pressure, heart rate, cardiac output and total peripheral resistance after vasodilatation were not significantly different from those after diazoxide alone.

2. Atropine, 0·04 mg/kg body weight, was given to 12 hypertensive patients chronically treated with β-adrenoreceptor blockade, before acute vasodilatation by diazoxide. Diazoxide caused no increase in heart rate after combined β-adrenoreceptor and parasympathetic blockade. However, cardiac output rose by 14 ± 5%.

3. We conclude that withdrawal of parasympathetic tone is an important determinant of circulatory homeostasis after acute vasodilatation during β-adrenoreceptor blockade.
Relation between Prognosis and the Blood Pressure before and during Treatment of Hypertensive Patients
Authors: Beevers D. G. , Johnston J. , Devine B. L. , Dunn F. G. , Larkin H. , Titterington D. M.
Published: August 2015

1. A study was conducted amongst 1247 treated hypertensive patients to determine the predictive power of untreated baseline and achieved treated blood pressures in the development of the complications of hypertension. In addition the relative importance of systolic and diastolic pressures was calculated.

2. Statistical analysis was done by calculating univariate differences in blood pressure between cases with and without complications. The higher the univariate distance, the greater the predictive power.

3. Blood pressures achieved during treatment were more important than baseline pressures for predicting stroke in both men and women, confirming the benefits of antihypertensive therapy in preventing strokes.

4. There was some evidence of prevention of myocardial infarction in men and of angina in women as a result of therapy.

5. There was no evidence to suggest that any one group of drugs, including β-adrenoreceptor-blocking drugs and thiazides, conferred any extra benefit in preventing coronary heart disease.

6. The systolic blood pressures achieved during treatment predicted stroke better than diastolic pressure, but no consistent trends were found for coronary heart disease.
Side-Effects of Antihypertensive Treatment: A Placebo-Controlled Study
Authors: Bauer G. E. , Baker J. , Hunyor S. N. , Marshall P.
Published: August 2015

1. A questionnaire, modified from Bulpitt & Dollery (1973), inquired about 20 symptoms commonly associated with hypertension or its drug therapy in 1017 subjects (age 30–69 years). Groups consisted of (a) active therapy, (b) placebo, (c) no tablets, and (d) a non-study control group. The response rate was 96% in the first three groups and 92% in group (d).

2. The subjects in groups (a), (b) and (c) constituted part of a placebo-controlled, patient-blind intervention study in the treatment of mild hypertension (The Australian National Blood Pressure Study).

3. After age/sex adjustment of the data, only sleepiness and self-assessed depression were found to be more common in the actively treated group. Impotence, failure of ejaculation and nocturia were age-related symptoms. Generally, complaint rate was higher in females.

4. The knowledge of a mild hypertensive condition or its modern drug therapy lead to very few symptoms in a non-hospital population who already have a fairly high ‘complaint level’.
Fluorescent Lipid-Peroxidation Products in Synovial Fluid
Authors: Lunec J. , Dormandy T. L.
Published: August 2015

1. Samples and extracts from synovial effusions were examined for the presence of fluorescent degradation products of free-radical oxidation (peroxidation).

2. Two classes of fluorescent compounds were identified and their fluorescence and physical properties are described. The fluorescence in the aqueous methanol phase of the extracts had the characteristics of conjugated Schiff bases.

3. Changes in synovial fluid and synovial fluid extracts in vitro induced by u.v. irradiation, prolonged incubation and the enzymic generation of oxidizing free radicals, with or without admixed peroxidizing arachidonic acid, and in the absence and presence of antioxidants, suggest that the fluorescent material is derived from peroxidized polyunsaturated lipids in damaged synovial tissue.
Renal Sodium Retention in Cirrhosis: Relation to Aldosterone and Nephron Site
Authors: Wilkinson S. P. , Jowett T. P. , Slater J. D. H. , Arroyo V. , Moodie H. , Williams R.
Published: August 2015

1. In a group of patients with cirrhosis who showed a wide range of values for the rate of renal sodium excretion, the latter was found to be inversely related to both the plasma concentration and rate of renal excretion of aldosterone. However, for a given sodium excretion the values for aldosterone were significantly lower in the patients than for a group of healthy control subjects. These findings suggest either an increased renal tubular sensitivity to aldosterone or the participation of other factors in the pathogenesis of the sodium retention.

2. Based on measurements of the rate of urine flow and the clearances of free water and inulin during a maximal water diuresis, the fractional reabsorption of sodium by the ‘proximal’, ‘diluting segment’ and ‘distal’ segments of the nephron was estimated. For patients retaining sodium the enhanced reabsorption occurred at both proximal and distal sites, the latter being quantitatively more important. There was no significantly enhanced sodium reabsorption in the diluting segment.
Subcellular Distribution of Radio-Labelled Iron during Intestinal Absorption in Guinea-Pig Enterocytes with Special Reference to the Mitochondrial Localization of the Iron
Authors: Hopkins J. M. P. , Peters T. J.
Published: August 2015

1. 59Fe-labelled ferric chloride was introduced into tied loops of guinea-pig jejunum.

2. After 5–30 min the loop was removed, the enterocytes were isolated, homogenized and subjected to analytical subcellular fractionation.

3. Uptake of 59Fe was extremely rapid and after 5 min 45% of the radioactivity sedimented in the mitochondrial fraction.

4. Density gradient centrifugation indicated that approximately 80% of this radioactivity was associated with the mitochondria themselves; the remainder was in brush-border fragments.

5. Selective disruption of the mitochondria demonstrates that the iron is localized to the matrix and the inner membrane, indicating transport of the absorbed iron into the organelle.

6. It is suggested that mitochondria are actively implicated at an early stage in the intestinal transport of iron.
The Effect of Different Pharmacological Agents on Respiratory Reflexes in Normal and Asthmatic Subjects
Authors: Thomson N. C.
Published: August 2015

1. The bronchial response to an anaesthetic aerosol of 4% bupivacaine hydrochloride has been investigated in normal and asthmatic subjects.

2. No significant changes in specific conductance were seen in normal subjects. In asthmatic subjects a significant fall in specific conductance occurred which was significantly reduced by prior treatment with ipratropium bromide.

3. Aerosols of bupivacaine, sodium cromoglycate and saline were tested on the cough reflex elicited by citric acid aerosol in normal and asthmatic subjects. Bupivacaine, but not the other agents, abolished the cough reflex in both groups of subjects.

4. Ipratropium bromide and bupivacaine were tested on methacholine-induced bronchoconstriction in normal and asthmatic subjects. Ipratropium bromide significantly prevented the fall in specific conductance in both groups of subjects whereas bupivacaine (normal subjects only tested) had no protective effect.

5. Ipratropium bromide, bupivacaine and sodium cromoglycate were tested on histamine-induced bronchoconstriction in normal subjects. Half the normal subjects had an upper respiratory tract infection. Ipratropium bromide significantly reduced the fall in specific conductance at 1 min after histamine but not at 5 or 10 min. Bupivacaine and sodium cromoglycate had no protective effect on histamine-induced bronchoconstriction at 1, 5 and 10 min.

6. Ipratropium bromide and bupivacaine were tested on prostaglandin F2α-induced bronchoconstriction in normal subjects. Neither drug prevented the change in specific conductance after prostaglandin F2α.

7. The possible significance of these results is discussed in relation to vagal mechanisms in the control of airways calibre in normal and asthmatic subjects.
Effect of the Exercise of Seven Consecutive Days Hill-Walking on Fluid Homeostasis
Authors: Williams E. S. , Ward M. P. , Milledge J. S. , Withey W. R. , Older M. W. J. , Forsling M. L.
Published: August 2015

1. The effect of 7 consecutive days of strenuous exercise, hill-walking, on water balance and distribution was studied in five subjects. The exercise was preceded and followed by 3 control days. The diet was fixed throughout but water was allowed ad libitum.

2. Packed cell volume was measured daily. Serum electrolytes and arginine vasopressin were measured twice daily. Daily water, sodium and potassium balances were calculated.

3. During exercise there was a fall in packed cell volume, reaching a maximum of 11% by day 5 and a retention of sodium reaching a cumulative maximum of 358 mmol by day 6. During and immediately after exercise there was a retention of potassium, reaching a total of 120 mmol by day 3 after stopping exercise.

4. There was a loss of 650 ml of water on day 1 of exercise, followed by a modest retention reaching a cumulative maximum of 650 ml on day 5 of exercise.

5. Neither arginine vasopressin nor serum electrolyte concentrations were affected by exercise.

6. From the packed cell volume, sodium and water balances it was calculated that by day 5 of exercise there was an increase in plasma volume of 0·68 litre (22%), an increase in interstitial fluid volume of 2·0 litres (17%) and a decrease in intracellular fluid volume of 1·8 litres (8%).

7. These changes, together with the clinical observation of facial and ankle oedema during the experiment, suggest that continuous exercise may cause oedema and thus may be a factor in the aetiology of high-altitude oedema.
Age-Dependent Changes in the Rate of Myofibrillar Protein Degradation in Humans as Assessed by 3-Methylhistidine and Creatinine Excretion
Authors: Tomas F. M. , Ballard F. J. , Pope L. M.
Published: August 2015

1. Urinary excretion of 3-methylhistidine and creatinine have been measured in normal male and female humans ranging in age from pre-term neonates to 68 years to assess changes in the rate of muscle protein degradation and in muscle mass.

2. The 3-methylhistidine excretion by six adult men was measured before and after subjects were transferred to meat-free diets. It was established that a meat-free diet should be eaten for a minimum of 3 days before urine collection to eliminate exogenous sources of 3-methylhistidine.

3. The 3-methylhistidine/creatinine excretion ratio declined about twofold between normal full-term birth and maturity. The ratio in pre-term neonates was higher than for full-term neonates.

4. The variability of 3-methylhistidine/creatinine ratios between individual untimed urine samples within a subject is similar to the variability between different subjects with total daily collections.

5. The 3-methylhistidine content of human muscle averaged 3·63 ± 0·06 μmol/g for subjects aged between 4 and 65 years with protein accounting for 20·4 ± 0·8% of muscle weight. These values are used to relate 3-methylhistidine excretion to muscle protein degradation.

6. It is concluded that control groups must be matched by age and sex to the group being examined. Where creatinine excretion is not perturbed it can be used as a reference base for comparisons of 3-methylhistidine excretion to indicate the average fractional degradation rates of muscle protein.
Neurogenic Activity–Angiotensin II Interaction during the Development and Maintenance of Renal Hypertension in the Rat
Authors: Bellini G. , Fiorentini R. , Fernandes M. , Onesti G. , Hessan H. , Gould A. B. , Bianchi M. , Kim K. E. , Swartz C.
Published: August 2015

1. Pentolinium tartrate (a ganglionic blocker) was injected in conscious rats during the early and late phases of two-kidney renal hypertension produced by aortic ligation.

2. In the early phase (5 days after aortic ligation), ganglionic blockade resulted in a decrease in blood pressure equal to that obtained in normotensive rats. Later, at days 12 and 40, for equally severe hypertension, ganglion blockade resulted in a greater decrease in blood pressure.

3. A 30 min infusion of [Sar1, Ala8]angiotensin II during the pentolinium-induced nadir in blood pressure resulted in a further decrease in blood pressure at day 5. Later, at days 12 and 40, this effect was smaller.

4. A 300 min infusion of [Sar1, Ala8]angiotensin II normalized the blood pressure in hypertensive rats at day 40. This delayed response may be secondary to a central effect of the antagonist, reducing neurogenic tone or peripheral antagonism of locally generated angiotensin II in the blood vessel walls.

5. At day 40, removal of the small left kidney resulted in a greater decrease in blood pressure. This suggests the presence of a renal factor other than renin in the chronic phase of this hypertension.
A Comparison of Chromium Sesquioxide and [51Cr]Chromic Chloride as Inert Markers in Calcium Balance Studies
Authors: Hesp R. , Williams D. , Rinsler M. , Reeve J.
Published: August 2015

1. Chromium sesquioxide (Cr2O3; 1·5 g/day) and [51Cr]chromic chloride [31CrCl3 (0·3 μCi/day)] were compared as continuously administered non-absorbed markers for the correction of faecal recoveries in 14 calcium balance studies each lasting at least 18 days.

2. The mean recoveries of each, 98·4% for Cr2O3 and 101·9% for 51CrCl3, were not significantly different from 100.

3. The two markers reduced the uncertainty in a typical 3 × 6 day calcium balance study to a similar extent (sd = 1·4 mmol/day for Cr2O3 and sd = 1·5 mmol/day for 51CrCl3).

4. 5lCrCl3 is a convenient and satisfactory alternative to Cr2O3 when the laboratory hazards associated with estimating the latter cannot easily be eliminated.
Characteristics of Renal Handling of Human Immunoglobulin Light Chain by the Perfused Rat Kidney
Authors: Smith J. F. Falconer , Van Hegan R. I. , Esnouf M. P. , Ross B. D.
Published: August 2015

1. The renal handling of purified human immunoglobulin light chain has been studied with an isolated perfused rat kidney preparation.

2. Human immunoglobulin light chain was freely filtered and largely reabsorbed. Fractional reabsorption was characteristic for each of four light chains and varied between 56% and 86%. No renal tubular maximum for human light chain was obtained.

3. Light chains at concentrations up to 10 times those seen in human myeloma were without effect on glomerular filtration rate or sodium and potassium reabsorption in experiments lasting up to 2h.

4. Filtered and reabsorbed light chain returned ultimately to the perfusion medium, indicating a unique property of the tubular handling of this protein. None of the inhibitors tested (ouabain, frusemide, acetazolamide, probenicid) influenced light chain reabsorption.

5. The results are taken to indicate that light chain reaches the site of the transport enzyme, Na+, K+−dependent ATPase, at concentrations which vary with the nature of the light chain. This may provide a mechanism for renal damage in patients with myeloma, after prolonged exposure.
Distribution of Endogenous Cobalamin between the Transcobalamins in Various Mammals
Authors: Linnell J. C. , Collings Lena , Down Margaret C. , England J.M.
Published: August 2015

1. Plasma samples from ten mammals were chromatographed on Sephadex G-200 columns and the total cobalamin content of each fraction was determined.

2. Unlike the situation in man, the bulk of the endogenous plasma cobalamin was found attached to a transcobalamin II-like protein in all ten animals. Transcobalamin 0 carried between 3 and 20%and this proportion appeared to be inversely related to the plasma total cobalamin. No endogenous cobalamin peak corresponding to transcobalamin I was detected in any species, though in the rabbit 5·3% of the plasma total cobalamin was attached to a protein of apparent molecular weight 176 000.
Haemodynamic Alterations after Reversal of Renal Hypertension in Rats
Authors: Hallbäck-Nordlander Margareta , Noresson E. , Lundgren Y.
Published: August 2015

1. Cardiac output, heart rate and mean arterial pressure were determined in two-kidney Goldblatt hypertensive rats of 4 weeks' duration, in matched normotensive controls and in declipped renal hypertensive rats 2 h-28 days after renal artery declipping.

2. After declipping mean pressure fell rapidly due to a corresponding reduction in total peripheral resistance, this being normalized after 1 day. Cardiac output and heart rate remained initially unchanged, but 1 day after declipping the former was significantly increased compared with output in renal hypertensive rats.

3. The initial normalization of total peripheral resistance must be ascribed to a subnormal vascular smooth muscle tone. The reason is that the hypertensive structural vascular changes are not yet significantly reduced and their presence implies an elevated flow resistance, even when vascular smooth muscle activity equals that in normotension.

4. This considerable ‘overshoot’ in vascular relaxation and lack of reflexogenic tachycardia, despite resetting of baroreceptors, suggest that peripheral as well as central mechanisms contribute to the rapid normalization of mean arterial pressure in two-kidney Goldblatt hypertension in rats, later stabilized by reversal of structural vascular changes.
Evidence for the Local Occurrence of Angiotensin II in Rat Kidney and its Modulation by Dietary Sodium Intake and Converting Enzyme Blockade
Authors: Mendelsohn F. A. O.
Published: August 2015

1. Angiotensin II (ANG II) was measured in acid-ethanol homogenates of rapidly frozen rat kidneys by a method involving ion-exchange and immunoadsorbent purification of peptides before radioimmunoassay.

2. Concentrations of ANG II found in kidney were 10–20 times that in plasma.

3. Perfusion of the kidneys via the renal artery with isotonic sodium chloride solution or with disodium EDTA solution did not alter the concentrations of intrarenal ANG II.

4. Animals fed on a sodium-deficient diet for 8 days had markedly higher concentrations of intrarenal ANG II, plasma renin activity and kidney renin concentration than sodium-replete animals.

5. After oral sodium loading for 3 weeks, rats had suppressed plasma renin activity and kidney renin concentration but unchanged intrarenal ANG II when compared with animals on a normal sodium intake.

6. One hour after the administration of a converting enzyme inhibitor (SQ 20881) plasma renin activity was elevated, kidney renin concentration unchanged and intrarenal ANG II was depressed.

7. These results demonstrate the presence of ANG II in the extravascular compartment of the kidney. They further suggest that its quantity is influenced by sodium intake and that angiotensin I converting enzyme is essential for its formation.
Cysteine—Homocysteine Mixed Disulphide: Differing Plasma Concentrations in Normal Men and Women
Authors: Wilcken D. E. L. , Gupta V. J.
Published: August 2015

1. The mixed disulphide of cysteine and homocysteine is known always to be present in the plasma of patients with homocystinuria, an abnormality of methionine metabolism. Recently we have shown that it is also detectable in low concentration in the plasma of normal fasting man. In the present study we measured mixed disulphide concentrations after an overnight fast in 24 normal men and compared the findings with those obtained in 24 normal premenopausal women of similar age.

2. The mean value for men (± sd) of 3·3 ± 0·8 μmol/l was significantly higher than that for women (2·4 ± 0·7 μmol/l; P < 0·001). Of the other neutral and acidic amino acids measured mean values for leucine, isoleucine and valine (P < 0·001) and cystine (P < 0·01) were also higher in the men but methionine concentrations were not significantly different.

3. The higher branched-chain amino acid concentrations in men could be related to larger muscle bulk and protein intake, but the higher cysteine—homocysteine mixed disulphide concentrations are consistent with differences in methionine metabolism between men and women under the age of 50 years.
Changes in Blood Glucose and Plasma Insulin after Intravenous Galactose in Human Injury
Authors: Elia M. , Oppenheim W. L. , Smith R. , Ilic Vera , Williamson D. H.
Published: August 2015

1. The increase in blood glucose after intravenous galactose was measured at 6−8 h and 14 days after hip replacement (14 patients) and accidental injury (14 patients).

2. After hip replacement there was a greater rise of glucose after galactose on the day of the operation than on recovery, despite basal hyperglycaemia. This earlier period was also associated with inappropriately low insulin concentrations for the prevailing glucose concentration, and hyperketonaemia (13 out of 14 patients).

3. After accidental injury patients with initial hyperketonaemia (nine out of 14) also had a greater rise of blood glucose after galactose than on recovery and had relative insulin deficiency; in contrast those who were initially normoketonaemic (five out of 14) showed a rise in glucose comparable with that after recovery and basal insulin concentrations more appropriate to the existing glucose concentration.

4. It is concluded that in most subjects after injury hepatic glucose release after galactose administration is not suppressed despite hyperglycaemia.
Effect of Vitamin D Deficiency on Sarcoplasmic Reticulum Function and Troponin C Concentration of Rabbit Skeletal Muscle
Authors: Pointon Jennifer J. , Francis M. J. O. , Smith R.
Published: August 2015

1. Weanling rabbits were made rachitic either by a vitamin D-deficient diet or by parenteral administration of ethane 1-hydroxy-1,1-diphosphonate (EHDP) in amounts sufficient in other species to block the formation of 1,25-dihydroxycholecalciferol [1,25-(OH)2D,].

2. The uptake of calcium into the isolated sarcoplasmic reticulum from mixed striated quadriceps muscle, and the amount of troponin C (the calcium-binding component of the troponin complex) in relation to other proteins from the same muscle, were measured.

3. In muscle from animals made rachitic by a dietary deficiency of vitamin D, the rate of uptake of calcium by the sarcoplasmic reticulum and the troponin C concentration were both significantly less (P < 0·02) than in control littermates. In EHDP-treated animals no significant differences from controls were found.

4. These results show that dietary deficiency of vitamin D in such animals can affect muscle physiology. Since no changes are found in animals made rachitic with EHDP, who presumably have a selective deficiency of 1,25-(OH)2D3, it is possible that the effect of vitamin D on muscle is mediated through metabolites other than 1,25-(OH)2D3 such as 25-hydroxycholecalciferol.
The Role of the Colon in the Pathogenesis of Hyperchloraemic Acidosis in Ureterosigmoid Anastomosis
Authors: McConnell J. B. , Murison J. , Stewart W. K.
Published: August 2015

1. The composition of urine-faeces mixture in seven patients with ureterosigmoid anastomosis has been studied by a dialysis in vivo method using cellulose bags. Urine—faeces dialysate obtained from these patients contained much greater amounts of both bicarbonate and total ammonia than has been reported for faecal dialysate in normal subjects.

2. Total ammonia concentrations in urine– faeces specimens obtained by catheter suggest that urine excreted by the kidneys in these patients becomes increasingly acid with increasing systemic acidosis. The highly alkaline nature of urine-faeces mixtures, especially in acidotic patients, indicates rapid alkalinization of the mixture in the colon. It appears that colonic secretion of bicarbonate is a direct consequence of the acidity of urine excreted by the kidney and draining into the colon.

3. The study suggests that the development of hyperchloraemic acidosis in patients with ureterosigmoid anastomosis is due to bicarbonate secretion by the colonic mucosa, with concomitant chloride absorption. With the development of metabolic acidosis, rapid alkalinization of the urine still occurs in the colon, but during further retention of the urine-faeces in the colon some reabsorption of bicarbonate occurs, probably in part by ionic diffusion since chloride concentration in the lumen increases.

4. Evidence suggestive of non-ionic diffusion of ammonia was found in only one patient. It seems probable that higher rates of urea breakdown in other patients mask the expected relationship between total ammonia and bicarbonate.
Sensitivity to Noradrenaline in Isolated Tail Arteries from Spontaneously Hypertensive Rats
Authors: Webb R. C. , Vanhoutte P. M.
Published: August 2015

1. The sensitivity of isolated tail artery strips from adult spontaneously hypertensive (SH) and normotensive rats to endogenously released and exogenously applied noradrenaline was compared. Release or displacement of endogenous noradrenaline was obtained with electrical stimulation, tyramine, elevated potassium and potassium-free solution. Isometric contractile responses were measured before and after acute denervation with 6-hydroxydopamine or before and after treatment with phentolamine.

2. The sensitivity to exogenous noradrenaline of innervated arterial strips was similar for SH and normotensive rats. Acute denervation produced a significant shift to the left in the concentration-response curve to noradrenaline only in SH rat arterial strips.

3. Contractile responses to electrical stimulation and tyramine were similar in both groups before denervation. Contractile responses to potassium-free solution were greater in SH than in normotensive arterial strips. After denervation the SH and normotensive vessels responded similarly to these interventions. Contractile responses to elevated potassium were similar in both groups before and after treatment with phentolamine.

4. The results suggest that the sensitivity of vascular smooth muscle cells to noradrenaline is greater in denervated arterial strips from SH rats than in those from normotensive rats. Under most experimental conditions, the junctional concentration of noradrenaline released or displaced from the adrenergic nerve endings is less in arterial strips from SH than in those from normotensive rats. Apparently, the adrenergic neuroeffector nerve terminals in hypertensive blood vessels can modulate the junctional concentration of noradrenaline so that the contractile response to this agent is similar to that in normotensive blood vessels.
Biochemical Alterations of Connective Tissue Metabolism in the Arterial Walls of Stroke-Prone Spontaneously Hypertensive Rats
Authors: Ooshima A. , Yamori Y. , Ohta K. , Nara Y. , Horie R.
Published: August 2015

1. The chemical characteristics of the vascular connective tissue components were determined in stroke-prone (SP), stroke-resistant (SR) spontaneously hypertensive (SH) rats and normotensive Wistar-Kyoto (WK) rats.

2. The ratio of hydroxylysine to hydroxylysine plus lysine in the vascular collagen was increased in 6-month-old SP—SH rats and SR—SH rats as compared with WK rats.

3. An age-related increase in uronic acid and hexose content of the aorta was noted in SP—SH, SR—SH and WK rats. However, the increase was more prominent in SH rats, especially SP—SH rats at the stages examined (11 weeks and over 8 months of age).

4. The ratio of galactosyl-hydroxylysine to glucosyl-galactosyl-hydroxylysine in the aortic collagen was decreased in 6-month-old SH rats, especially SP—SH rats as compared with WK rats.

5. A relative increase in β and γ components in aortic collagen was noted in 6-month-old SP—SH rats when compared with SR—SH rats.

6. The increased content of uronic acid and hexose and the structural changes of vascular collagen as demonstrated in SP—SH rats might be releated to the fragility of the arterial wall and/or to the pathogenesis of stroke-proneness.
Changes in Arterial Blood Gases during and after a Period of Oxygen Breathing in Patients with Chronic Hypercapnic Respiratory Failure and in Patients with Asthma
Authors: Rudolf M. , Turner J. A. McM. , Harrison B. D. W. , Riordan J. F. , Saunders K. B.
Published: August 2015

1. Ten patients with chronic hypercapnic respiratory failure (group 1) and eight patients with asthma (group 2) breathed pure O2 from an MC mask for 60 min. Blood gases were measured during this period and for the subsequent 45 min.

2. In nine of ten patients in group 1 and in all eight patients in group 2 arterial O2 tension (Pa,o2) fell to values lower than had been obtained before O2 was given.

3. These undershoots in Pa,o2 are unrelated to changing CO2 stores or to hypoventilation, and are more likely due to persistence of altered ventilation-perfusion ratios associated with O2 breathing.

4. Magnitude of the undershoots is usually small, and periods of less than 15 min off O2 are unlikely to be harmful.
Studies on the Renin-Angiotensin-Aldosterone System in Elderly Hypertensive Patients with an Angiotensin II Antagonist
Authors: Ogihara T. , Hata T. , Maruyama Anna , Mikami H. , Nakamaru M. , Mandai T. , Kumahara Y.
Published: August 2015

1. To characterize the renin-angiotensin-aldosterone system in elderly hypertensive patients, an angiotensin II antagonist, [Sar1,Ile8]angiotensin II, was infused into individuals 60 years old and older with and without hypertension.

2. After infusion of [Sar1,Ile8]angiotensin II in all of the elderly patients and subjects an agonistic pressor response was observed that was greater than in middle-aged hypertensive patients.

3. Pre-infusion plasma renin activity and plasma aldosterone concentration in hypertensive and normotensive elderly groups were suppressed in comparison with those in middle-aged hypertensive subjects. The increased agonistic effects of [Sar1,Ile8]angiotensin II infusion on blood pressure in the elderly are presumably due to their hyporeninaemia.

4. The angiotensin-aldosterone system in elderly essential hypertensive patients is suppressed and is presumably not responsible for their elevated blood pressures.
Direct Radioimmunoassay and Immunocytochemical Localization of Renin in Human Kidneys
Authors: Ménard J. , N'goc P. W. , Bariety J. , Guyenne P. T. , Corvol P.
Published: August 2015

1. Highly specific antibodies to human renin were prepared in rabbits and used for the preparation of a renin-free substrate, the direct radioimmunoassay of renin in plasma and kidneys, and the localization of renin with fluoresceinated antibodies.

2. In a patient with a partially infarcted kidney, plasma renin activity was increased, and could be activated by acid. The direct measurement of plasma renin by radioimmunoassay gave identical values before and after acidification.

3. In the ischaemic part of the kidney, renin content was high, both by the enzymatic and the direct method of measurement. It was low in the non-ischaemic part of the kidney.

4. All afferent and some interlobular arteries of the obsolescent glomeruli were stained with fluoresceinated anti-renin antibodies. In the non-ischaemic area, the juxtaglomerular apparatus did not stain.

5. Renin can now be measured in human plasma and kidney as an entity, by a specific radioimmunoassay. A direct investigation of this intrarenal hormone is now possible at the renal tissue level.
Acute and Chronic Effects of Nifedipine on Plasma Renin Activity and Plasma Adrenaline and Noradrenaline in Controls and Hypertensive Patients
Authors: Corea L. , Miele N. , Bentivoglio M. , Boschetti E. , Agabiti-Rosei E. , Muiesan G.
Published: August 2015

1. Nifedipine, a calcium antagonist drug, was given sublingually (10 mg) to seven normal subjects and 19 patients with essential hypertension. In addition, 12 of the hypertensive subjects then received nifedipine (10 mg thrice daily) for 3 weeks.

2. Sublingual administration of nifedipine in hypertensive patients induced a prompt and sustained reduction of blood pressure, without a significant increase of heart rate; in normotensive subjects blood pressure did not change, and heart rate was significantly increased. After chronic treatment, blood pressure remained reduced and heart rate did not rise.

3. Plasma catecholamines and plasma renin activity increased significantly in normotensive subjects after acute administration.

4. After both acute and chronic administration, only plasma noradrenaline was significantly increased in hypertensive patients; in long-term treatment, it was increased in both the lying and standing positions.

5. Nifedipine is an active antihypertensive drug, which may induce some degree of sympathetic activation.
Contribution of the Kidneys but not Adrenal Glands to the Acute Antihypertensive Effects of Captopril in Spontaneously Hypertensive Rats
Authors: Antonaccio M. J. , High J. P. , Rubin B. , Schaeffer T.
Published: August 2015

1. Captopril (100 mg/kg, orally) decreased blood pressure in spontaneously hypertensive (SH) rats.

2. Bilateral adrenalectomy either before or after captopril administration did not alter the antihypertensive effect of captopril.

3. Bilateral nephrectomy reversed the established antihypertensive effect of captopril and prevented any change in blood pressure to a subsequent dose of captopril.

4. It is concluded that kidneys but not adrenal glands are essential to the antihypertensive actions of captopril in SH rats.
Does the Renin—Angiotensin System Maintain Blood Pressure in Both Hypertensive and Normotensive Subjects? a Comparison of Propranolol, Saralasin and Captopril
Authors: MacGregor G. A. , Markandu N. D. , Roulston J. E.
Published: August 2015

1. Propranolol, saralasin and captopril changed blood pressure in normotensive as well as hypertensive subjects.

2. The percentage change in blood pressure with these three drugs for a given plasma renin activity was similar in normotensive and hypertensive subjects.

3. This suggests that when the renin-angiotensin system is maintaining blood pressure, it maintains the blood pressure to the same extent in percentage terms in normotensive and hypertensive subjects for a given plasma renin activity.

4. Saralasin has marked agonist activity, and probably underestimates the participation of the renin—angiotensin—aldosterone system in the maintenance of blood pressure. The fall in blood pressure that occurred with captopril in normal subjects on their normal sodium intake suggests that the renin—angiotensin—aldosterone system may have an important role in the control of blood pressure in normal subjects on their normal sodium intake. If it does, our results suggest that the renin—angiotensin—aldosterone system plays no greater role in maintaining blood pressure in patients with essential hypertension than normotensive subjects for a given plasma renin activity.
Effects of an Angiotensin Converting Enzyme Inhibitor on Psychosocial Hypertension in Mice
Authors: Henry J. P. , Vander A. J. , Stephens P. M.
Published: August 2015

1. Renin-associated, chronic psychosocial hypertension of 150–160 mmHg develops in groups of mice interacting socially in complex population cages.

2. The blood pressures of 16 males in a cage were measured and an intraperitoneal injection of the angiotensin coverting enzyme inhibitor captopril (SQ 14 225) was given. Three hours later blood pressures were measured again.

3. During the first 3 weeks of psychosocial hypertension SQ 14 225 was without effect. But at 1 month and subsequently up to 7 months, SQ 14 225 reduced blood pressure to the normal range of 120–130 mmHg.

4. Plasma renin activities were not related to the extent of blood pressure reduction by SQ 14 225. Hence other factors in addition to the renin—angiotensin mechanism play a part in maintaining chronic psychosocial hypertension.
A Sympathetic Pressor Reflex in the Conscious Dog
Authors: Pagani M. , Bergamaschi M. , Malliani A.
Published: August 2015

1. The effects of mechanical activation of aortic sympathetic sensory fibres have been studied in conscious dogs.

2. A cannula covered by an inflatable rubber balloon, previously implanted in the descending thoracic aorta, was used to stretch the aortic walls without obstructing blood flow.

3. Aortic stretch significantly increased mean arterial blood pressure and heart rate from control values in the absence of pseudo-affective reactions.

4. This response indicates that positive feedback sympathetic reflexes are operative in the conscious, fully innervated animal.
Noradrenaline Clearance in Hypertensive Patients with Various Degrees of Renal Function
Authors: Masuyama Yoshiaki , Nishimura Takuzo , Nishio Ichiro , Kuchii Masato
Published: August 2015

1. Hypertensive patients with normal renal function showed significantly higher plasma urinary noradrenaline than the normotensive controls, and the hypertensive patients with mild to moderate disturbance of renal function showed the same noradrenaline concentration as the controls.

2. Hypertensive patients with severe renal function disturbance showed significantly higher plasma noradrenaline concentrations and lower urinary noradrenaline excretion than the controls.

3. Noradrenaline clearance calculated by free plasma noradrenaline and total urinary noradrenaline was significantly decreased in those subjects with severe renal dysfunction.

4. Conjugated plasma noradrenaline was increased in the hypertensive patients with the severe disturbance of renal function, and conjugated urinary noradrenaline increased in those without severe renal dysfunction.
Is Blood Pressure Variability Related to Activity of the Sympathetic System?
Authors: Clement D. L. , Mussche M. M. , Vanhoutte G. , Pannier R.
Published: August 2015

1. In 70 patients with untreated essential hypertension, blood pressure variability was correlated to plasma catecholamines and to the response of blood pressure and peripheral flow to cold pressure and handgrip tests.

2. Supine blood pressure was recorded every 5 min, during 3 h. Variability was defined as the standard deviation of the mean of the readings in that period.

3. Blood pressure variability is positively and significantly correlated to the level of pressure and to age.

4. No significant correlation could be found with plasma catecholamines and sympathetic function tests.

5. It is concluded that blood pressure variability is related to the level of pressure but not to activity of the sympathetic nerves.
The Effect of Mental Stress on Prostaglandin F2α in Patients with Essential Hypertension and in Healthy Subjects
Authors: Ignatowska-S̀witalska H. , Klonowicz T. , Feltynowski T.
Published: August 2015

1. The influence of mental stress, 30 min Kraepelin's arithmetic test under noise on the plasma concentration and urinary excretion of prostaglandin (PG) F2α was studied in patients with essential hypertension and in healthy subjects.

2. Before the arithmetic test the plasma PGF2α in hypertensive patients was significantly higher than in healthy subjects. The mental stress produced a significant increase in plasma PGF2α in healthy subjects but not in patients with essential hypertension.

3. Three hour urine excretion of PGF2a before stress was about two times lower in hypertensive patients than in healthy subjects. After exposure to stress a significant decrease in urinary excretion of PGF2α was found in healthy subjects, but not in hypertensive patients.

4. The stress-induced increase in plasma PGF2α of healthy subjects may reflect elevated brain PGF2α synthesis. The individual differences in response to stress in hypertensive patients may result from specific impairments in synthesis and/or prostaglandin turnover.
Adrenocorticotropin Inhibition of Mineralocorticoid Hormone Production
Authors: Biglieri E. G. , Chang B. , Hirai J. , Brust N. , Rost C. R. , Schambelan M.
Published: August 2015

1. Adrenocorticotropin (ACTH)-induced steroidogenesis, obtained by continuous administration of ACTH for 3 days, produces in man (a) sustained elevations of plasma deoxycorticosterone and cortisol concentrations, (b) transient elevations of plasma aldosterone and 18-hydroxycorticosterone concentrations that return to near-control values, and (c) brisk initial increases in plasma 18-hydroxydeoxycorticosterone and corticosterone concentrations that fall to 20–68% of peak values 30 h thereafter.

2. Dexamethasone (8 mg/day, orally) treatment for 2 days in man permits a greater postural increase in plasma aldosterone and 18-hydroxycorticosterone concentrations. A dampening effect of ACTH is suggested.

3. An ACTH-initiated inhibition of 11β- and 18-hydroxylation is proposed to be operative in regulation of mineralocorticoid hormones.
Reactive Hyper-Reninaemia to Angiotensin Blockade Identifies Renovascular Hypertension
Authors: Case D. B. , Atlas S. A. , Laragh J. H.
Published: August 2015

1. Saralasin and converting enzyme inhibitors SQ 20881 and captopril induced increases in plasma renin activity to greater than 14 ng h−1 ml−1 in 43 out of 44 patients with untreated renovascular hypertension when studied in the seated position and on normal sodium intake. This degree of response was absent in patients with normal-renin essential hypertension and present in only three out of 26 with high-renin essential hypertension.

2. Reductions of greater than approximately 9% in diastolic pressure in response to these three drugs occurred regularly in renovascular hypertension (95%) but also frequently in high-renin (65%) and normal-renin (26%) essential hypertension.

3. Prior sodium depletion abolished the specificity of the renin and depressor responses to angiotensin blockage for renovascular hypertension.

4. Some patients with bilateral renovascular and all with malignant hypertension also exhibited these responses to angiotensin blockade that are characteristic of unilateral renovascular hypertension.