bluuebunny/crossref_metadata_2025_split huggingface dataset:
Endogenous Opioids Modulate Central Nervous System Blood Pressure Control in Man
Authors: Rubin P. C. , McLean Kathleen , Reid J. L. 
Published: August 2015

1. Two studies were performed to elucidate the role of opioids in blood pressure control in man.
2. Study 1: nine normal subjects, 18–32 years, received in a randomized single blind manner, volume matched infusions of a Met-enkephalin analogue (DAMME) 0.5 mg, naloxone 0.2 mg/kg or saline. Blood pressure, heart rate and plasma noradrenaline were determined supine and after a 5 min, 70° head-up tilt at 0, 3/4, 2, 3, 4, 5 and 6 h.
3. Study 2: seven subjects, after baseline recordings of blood pressure and heart rate received six incremental infusions of sodium nitroprusside, 1.5–7.5 μg min−1 kg−1. They then received DAMME or naloxone and the nitroprusside infusions were repeated between 3 and 4 h. There was a significant linear relationship between fall in mean arterial pressure and rise in heart rate in each case and the slope was used as an index of baroreflex sensitivity.
4. Neither naloxone nor DAMME influenced supine blood pressure or heart rate. Blood pressure after head-up tilt was significantly (analysis of variance) decreased by DAMME for up to 5 h but not by naloxone, the effect being most marked at 3 h: systolic (mean ± sd), placebo 110 ± 6, naloxone 106 ± 10, DAMME 96 ± 16 (P&lt; 0.02); diastolic (mean ± sd), placebo 78 ± 7, naloxone 79 ± 5, DAMME 67 ± 8 (P &lt; 0.01). The increases in heart rate and plasma noradrenaline on tilting after DAMME were not significantly different from values with placebo or naloxone. The 3 h values for heart rate were: placebo 87 ± 16, naloxone 88 ± 19, DAMME 89 ± 23 (P &gt; 0.1); for plasma noradrenaline (nmol/l): placebo 6.0 ± 2.2, naloxone 5.8 ± 1.9, DAMME 6.0 ± 1.9 (P &gt; 0.1).
5. Naloxone significantly increased the slope (beats per min/mmHg) of the regression relationship from a mean of 1.8 ± 0.07 to 3.0 ± 1.3 (P &lt; 0.05), and DAMME reduced the slope from 2.7 ± 1.7 to 1.2 ± 0.5 (P &lt; 0.05).
6. We conclude that endogenous opioids modulate baroreflex function in man.
Reversal of Left Ventricular Hypertrophy after Treatment of Hypertension by Atenolol for One Year
Authors: Sau F. , Cherchi A. , Seguro C. 
Published: August 2015

1. Fifteen patients with essential hypertension, class I, II WHO, nine males and six females, whose mean age was 46 years, were given atenolol, 100 mg a day, for 1 year.
2. After 1 month, compared with control, systolic and diastolic blood pressures, heart rate and cardiac output were reduced, whereas left ventricular end-diastolic dimension and stroke volume were increased and total vascular resistances, wall stress, left ventricular mass and h/diastolic radius (R) ratio were unchanged.
3. After 1 year, compared with control, systolic and diastolic blood pressures, heart rate and cardiac output were still reduced, total vascular resistance and wall stress were unchanged. End-diastolic dimension and stroke volume reverted to previous values; left ventricular mass and h/R ratio were significantly decreased.
4. These results show that left ventricular hypertrophy in essential hypertension can revert after 1 year of treatment with atenolol, at least in relatively young people. Since the left ventricle wall stress was not changed after atenolol, the regression of left ventricle hypertrophy seems prevalently to be related to the decrease of adrenergic activity of the heart.
Role of Adrenergic Overactivity and Pressure Overload in the Pathogenesis of Left Ventricular Hypertrophy in Borderline and Sustained Essential Hypertension in Man
Authors: Corea Luigi , Bentivoglio Maurizio , Verdecchia Paolo , Motolese Mario 
Published: August 2015

1. In 16 borderline and 18 sustained hypertensive patients, interventricular septal thicknesses (by echocardiography) were greater than those found in 18 healthy subjects. Values in borderline and sustained hypertensives did not differ significantly.
2. In healthy subjects and borderline hypertensive patients, posterior wall thicknesses were normal, whereas they were greater in sustained hypertensive patients than in the former two groups.
3. In borderline hypertension, interventricular septal thickness was positively correlated with resting supine (r = 0.89, P &lt; 0.001) as well as upright (r = 0.60, P &lt; 0.01) plasma noradrenaline, but not with adrenaline, plasma renin activity and mean blood pressure.
4. In sustained hypertension, posterior wall thickness was positively correlated with mean blood pressure (r = 0.85, P &lt; 0.001), but not with noradrenaline, adrenaline and plasma renin activity.
5. In human hypertension, left ventricular hypertrophy seems to involve only the interventricular septum in the borderline stage, extending to the posterior wall in the sustained stage. Adrenergic overactivity could play an important role in development of interventricular septal hypertrophy in borderline hypertension, whereas pressor factors could be mainly involved in the development of posterior wall hypertrophy in sustained hypertension.
Anatomical and Physiological Aspects of Cardiovascular Function in Wistar—Kyoto and Spontaneously Hypertensive Rats at Birth
Authors: Gray Sarah D. 
Published: August 2015

1. The present study was designated to determine whether there are any detectable differences in cardiovascular anatomy or physiology between Wistar-Kyoto (WKY) and spontaneously hypertensive rat (SHR) pups at birth.
2. It was found that mean arterial pressures were significantly higher, heart rates were slightly higher, and heart weight/body weight ratios were higher in SHR.
3. Vascular dimensions were determined in a small sample of those rats, and the data there also indicate hypertrophy to some degree: the ratio of wall thickness/lumen radius was higher in SHR, tangential wall tension and number of cell layers in the media were increased.
4. It is concluded that some of the concomitant features of hypertension, such as left ventricular wall hypertrophy and arterial wall hypertrophy, may be genetically determined to some extent in SHR.
Body Fat and Glucose Tolerance in Early Blood Pressure Elevation: Its Relation to Arteriolar Hypertrophy
Authors: Andersson Ove , Sivertsson Ramon , Sannerstedt Rune , Beckman Marie , Magnusson Marie , Sjöström Lars , Björntorp Per 
Published: August 2015

1. Forty-four young men with blood pressure elevation and 29 age-matched volunteer subjects were examined with invasive blood pressure and cardiac output measurements. The regional blood flow resistance of the hand during hyperaemia was calculated from blood pressure and flow data from venous occlusion plethysmography.
2. In a re-examination 5 years later the same protocol was applied and an oral glucose tolerance test was performed with glucose and insulin determinations. Body composition was calculated from total body potassium data (whole body 40K counter) and body weight.
3. Patients with blood pressure elevation were characterized by a significantly higher cardiac index at rest, and a significantly increased resistance during hyperaemia of the hand in comparison with that of the controls. The patients with blood pressure elevations were also divided according to cardiac output. The hyper-kinetic subgroup did not have an increased resistance during hyperaemia. Patients with blood pressure elevation had significantly increased body weight and body mass index in comparison with controls and there was a significant correlation between body wieght and regional resistance during hyperaemia.
4. In the re-examination it was found that the body weight difference between patients with blood pressure elevation and normotensive controls was explained by increased body fat. There was no difference in body weight between the normokinetic and hyperkinetic subgroups of patients with blood pressure elevation but the former group had significantly increased insulin concentrations on the glucose load.
5. Significant correlations were demonstrated between body weight, body fat and insulin concentration 30 min after glucose load against resistance during hyperaemia as the dependent variable. A multiple regression coefficient of 0.59 was found between the three independent variables and resistance during hyperaemia. Furthermore, the addition of the insulin concentration variable to the two independent variables body weight and body fat increased significantly the multiple regression coefficient.
Effects of Aging on the Variability of Arterial Pressure in Essential Hypertensive Patients
Authors: Ogawa Jun , Takata Shigeo , Nomura Gakuji , Arai Shiro , Ikeda Takayuki , Takabatake Toshikazu , Hattori Nobu 
Published: August 2015

1. We studied the effects of aging on the variability of blood pressure in mild to moderate essential hypertensive subjects.
2. Cardiac index was greater and total peripheral resistance index was less in patients under 40 years (by an average of 1.06 litres min−1 m−2 and 9.23 mmHg 1−1 min−1 m−2) than in those over 40 respectively (P &lt; 0.001 for each).
3. Pulse pressure/stroke volume was less by an average of 0.345 mmHg/ml in patients under 40 years than that in those over 40 (P &lt; 0.001). Pulse pressure/stroke volume was correlated with age (r = 0.621), average systolic blood pressure (r = 0.623) and inversely with baroreflex sensitivity (r = −0.494).
4. Baroreflex sensitivity was less by an average of 3.1 ms/mmHg in patients over 30 years than in those under 30 (P &lt; 0.025). Baroreflex sensitivity was inversely correlated with age (r = −0.617) and average systolic blood pressure (r = −0.589).
5. Beat by beat variability of systolic blood pressure was correlated with age (r = 0.460), particularly when the data of those in their twenties were excluded (r = 0.618), and significantly with pulse pressure/stroke volume (r = 0.650), average systolic blood pressure (r = 0.618) and inversely with baroreflex sensitivity (r = −0.477). These relationships were not observed for diastolic blood pressure.
6. Maximum difference in systolic blood pressure in a day was correlated with pulse pressure/stroke volume (r = 0.482) and average systolic blood pressure (r = 0.648) but not with baroreflex sensitivity. These relationships were not observed for diastolic blood pressure.
7. Variability of systolic blood pressure in patients over 30 years gradually increased with age. In contrast, those of systolic and diastolic blood pressures in subjects in their twenties were relatively large. This might be related to factors other than aging, presumably those which underlie the hyperdynamic circulatory state.
Greater Antihypertensive Efficacy of the Calcium Channel Inhibitor Verapamil in Older and Low Renin Patients
Authors: Bühler Fritz R. , Hulthén U. Lennart , Kiowski Wolfgang , Bolli Peter 
Published: August 2015

1. The calcium slow channel inhibitor verapamil was administered as monotherapy (240-270 mg; mean 427 mg/day) on the average for 93 days to 43 patients with essential hypertension; 11 with low, 24 with normal and eight with high renin sodium index.
2. Verapamil reduced blood pressure from 171 ± 16/108 ± sd 6 mmHg to 152 ± 14/93 ± 9 (both P &lt; 0.001); in 25 of the 43 patients a diastolic pressure ≤95 mmHg was achieved. Two patients each reported vertigo, sleeplessness and constipation.
3. The fall in mean blood pressure after verapamil was directly related to age (r = 0.759, P &lt; 0.001), pretreatment mean blood pressure (r = 0.701, P &lt; 0.01) and plasma noradrenaline concentration (r = 0.400, P &lt; 0.05), and inversely related to plasma renin activity (r = −0.551), P &lt; 0.001). These correlations were also significant for diastolic blood pressure. Accordingly, the antihypertensive response to verapamil was greatest in older and low renin patients.
4. This greater blood pressure decrease with verapamil in older and low renin patients suggests a greater calcium influx-dependent vasoconstriction in these patients, which seems to be directly related to the activity of the sympathetic nervous system.
Effect on High Density Lipoprotein Cholesterol of Atenolol and Oxprenolol in Patients with Mild Essential Hypertension
Authors: Kjeldsen S. E. , Eide I. , Leren P. , Foss O. P. 
Published: August 2015

1. Nineteen healthy men aged 50 years, with untreated, mild essential hypertension WHO group I, were randomized into two groups to study the effect of treatment (18 weeks) with oxprenolol (n = 10) and atenolol (n = 9) on serum cholesterol fractions, total triglycerides and uric acid.
2. Oxprenolol lowered high density lipoprotein (HDL) cholesterol by 11.4% (P &lt; 0.02) and cholesterol ratio (HDL cholesterol × 100/LDL + VLDL cholesterol) by 13.7% (P &lt; 0.05). Atenolol lowered HDL cholesterol by 16.5% (P &lt; 0.02) and cholesterol ratio by 19.2% (P &lt; 0.01).
3. Oxprenolol and atenolol raised total triglycerides by 20.0% and 17.9% respectively. Only with atenolol was this increment statistically significant (P &lt; 0.05).
4. The HDL cholesterol lowering effect of oxprenolol and atenolol observed in the present study may have clinical importance, since such metabolic side effects have been postulated to counteract the beneficial effect of blood pressure reduction on development of atherosclerosis and coronary heart disease in mild essential hypertension.
Cholinergic Manifestations of the Acute Autonomic Reaction to Hypoglycaemia in Man
Authors: Corrall R. J. M. , Frier B. M. , Davidson N. McD. , Hopkins W. M. , French E. B. 
Published: August 2015

1. The effects of insulin-induced hypoglycaemia on pupil size, parotid salivary secretion and sweating were studied in seven normal volunteers.
2. Hypoglycaemia was associated with an acute stimulation of parotid salivary secretion and of sweating, synchronous in onset with the rise in heart rate. There was no clear evidence of concurrent pupillary constriction.
Relationship between Primary Biliary Cirrhosis and Chronic Graft versus Host Disease: Investigation of Histocompatibility (HLA) Antigenic Determinants in Biliary Tract Antigens
Authors: McFarlane I. G. , McFarlane B. M. , Haines A. J. , Eddleston A. L. W. F. , Williams Roger 
Published: August 2015

1. According to a recent hypothesis, based on similarities between chronic graft versus host disease and primary biliary cirrhosis (PBC), immune reactions against histocompatibility (HLA) antigens-6-be responsible for the bile duct damage and extrahepatic lesions of PBC.
2. Previous studies have demonstrated autoimmune reactions in PBC against normal human biliary tract antigens. To equate these findings with the above hypothesis, it has been suggested that the biliary antigens are related to the HLA system and, in the present study, this possibility has been investigated by: (a) using preparations of the biliary antigens to inhibit the lymphocytotoxic activity of standard HLA-typing sera against normal lymphocytes, and (b) employing guinea-pig antisera raised against the biliary antigens as ‘typing reagents’ in the lymphocytotoxicity test to determine whether these antisera recognize HLA components on the surfaces of normal lymphocytes.
3. No inhibition by the biliary antigens of the reaction of two standard typing sera against T-and B-lymphocytes from two normal healthy donors (covering nine HLA-A, -B, -C and three HLA-DR loci antigens) was observed. Conversely, the guinea-pig antisera showed no reaction against these lymphocytes.
4. The results suggest that the biliary tract antigens are probably not related to ‘common’ antigenic determinants associated with the HLA system.
Trypsin-Activatable Inactive Renin in Rat Plasma
Authors: Glorioso Nicola , Madeddu Paolo , Dessi'-Fulgheri Paolo , Fois Giuseppe , Meloni Franca , Bandiera Francesco , Tonolo Giancarlo , Rappelli Alessandro 
Published: August 2015

1. Activation of inactive renin in rat plasma has been studied with different trypsin concentrations and incubation times at pH 6.2 and 4°C.
2. Trypsin concentrations below 2 mg/ml, lower than endogenous rat plasma anti-trypsin activity, do not activate inactive renin, whereas maximal activation is obtained with trypsin at 6 mg/ml for 1 min at 4°C, pH 6.2.
3. Under these conditions trypsin can cleave dialysable fragments from renin substrate. ANG I can be generated at 37°C with a pH optimum of 5.3. Nevertheless, the ANG I formation at pH 6.2 was totally unaffected.
4. Incubations longer than 2 min with trypsin at 6 mg/ml can induce a direct cleavage of dialysable ANG I-containing fragments strongly interfering with the measurements of renin activity at pH 6.2.
5. On average 40% of the total renin measured in plasma of normotensive WK rats is in the inactive form, although a wide range of variation is observed.
Clearance and Non-Invasive Determination of the Hepatic Extraction of Indocyanine Green in Baboons and Man
Authors: Grainger S. L. , Keeling P. W. N. , Brown I. M. H. , Marigold J. H. , Thompson R. P. H. 
Published: August 2015

1. The disposition of an intravenous bolus of indocyanine green (ICG) has been studied in healthy man and baboons using a novel analysis of a two compartment pharmacokinetic model.
2. This analysis enabled the hepatic extraction ratio (ER) of dye to be determined solely from the plasma disappearance curve, and the ER determined did not differ from that measured by hepatic vein catheterization.
3. When compared with clearance measured at steady state, the two compartment model gave a significantly more accurate determination of plasma clearance than did the conventional one compartment model.
4. It is concluded that, in health, liver blood flow may be calculated accurately and noninvasively after a single intravenous injection of ICG.
Recovery of Infused [14C]Bicarbonate as Respiratory 14CO2 in Man
Authors: Clugston Graeme A. , Garlick Peter J. 
Published: August 2015

1. Nine adult subjects (eight obese, one normal) were infused with NaH14CO3 for up to 36 h.
2. The recovery of label as respiratory 14CO2 was close to 90% throughout and did not change with feeding or with dietary composition.
Growth Hormone-Induced Changes in Myofibrillar Protein Breakdown in Hypopituitary Children
Authors: Ballard F. J. , Burgoyne J. L. , Tomas F. M. , Penfold J. L. 
Published: August 2015

1. Creatinine and Nτ-methylhistidine excretion rates have been measured in 13 hypopituitary children to calculate the body muscle contents and rates of myofibrillar protein breakdown. Analyses have been made during periods of growth hormone withdrawal and subsequent administration.
2. The creatinine excretion rate was lower in the hypopituitary children, indicating a lower muscle content per kg body weight. This difference persisted even in children who had received growth hormone for several years.
3. Excretion of Nτ-methylhistidine was reduced by the administration of growth hormone.
4. The fractional breakdown rate of myofibrillar protein, as calculated from the Nτ-methylhistidine to creatinine molar excretion ratio, averaged 1.76%/day in the four youngest children during growth hormone withdrawal. This was significantly higher than for control children of a similar age (P &lt; 0.02) and was reduced to the normal rate of 1.47%/day by growth hormone administration.
5. in older children the fractional rate of myofibrillar protein degradation remained in the normal range irrespective of growth hormone treatment.
6. These results are discussed in the context of the anabolic effects of growth hormone on muscle being partly explained by its action to decrease rates of protein breakdown.
Post-Adrenalectomy Hypotension in Rats; Absence of Baroreflex Resetting or Effect of Naloxone
Authors: Gardiner S. M. , Bennett T. 
Published: August 2015

1. Male Wistar rats were either bilaterally adrenalectomized or sham-operated, and given 1% sodium chloride solution instead of tap water to drink. Seven days later, arterial blood pressures were recorded directly from conscious freely moving rats.
2. Systolic and diastolic blood pressures were significantly lower in the adrenalectomized rats, whereas heart rates were significantly higher than in sham-operated animals. The tachycardia was due to a combination of sympathetic hyperactivity and reduced vagal tone, which may have been reflex responses to a reduction in effective blood volume.
3. Baroreflex control of the sinus node was assessed from the pulse interval responses to rises (induced by methoxamine) or falls (induced by glyceryl trinitrate or sodium nitroprusside) in systemic arterial blood pressure. The relation between pulse interval and systolic blood pressure was described by the same curve in sham-operated and adrenalectomized rats, indicating that, in the latter, there was no change in baroreflex setting or sensitivity.
4. Intravenous administration of naloxone (2mg/kg) had no effect on systemic arterial blood pressure in adrenalectomized rats, suggesting that endogenous opiates were not contributing to the hypotension.
The Presence in Normal Plasma, Serum and Platelets of Factors That Stimulate the Production of Prostacyclin (PGI2) by Cultured Endothelial Cells
Authors: Seid J. M. , Jones P. B. B. , Russell R. G. G. 
Published: August 2015

1. The effect of plasma and serum from normal subjects on the production of prostacyclin by cultured porcine endothelial cells was investigated.
2. Both plasma and serum from all subjects studied significantly stimulated the production of prostacyclin by cultured endothelial cells, measured by the radioimmunoassay of its stable metabolite 6-oxoprostaglandin F1α.
3. Serum caused a consistently greater stimulation than plasma from the same individual. The stimulation was dose-dependent and inhibited by indomethacin. Heparin added to serum also inhibited this response.
4. Extracts from isolated washed platelets were tested for their ability to increase prostacyclin production. Extracts from platelets which had been induced to aggregate and release their granule contents in response to thrombin, caused stimulation.
5. These results indicated the invariable presence in plasma and serum of factors that stimulate the production of prostacyclin by endothelial cells in vitro. At least one of these factors is derived from platelets. These factors may be involved in the regulation of prostacyclin production by the vascular endothelium under normal conditions and in disease states.
A Signal Detection Theory Analysis of the Effect of Chest Cage Restriction upon the Detection of Inspiratory Resistive Loads
Authors: Narbed P. G. , Marcer D. , Howell J. B. L. , Spencer E. 
Published: August 2015

1. By the use of Signal Detection Theory techniques, resistive load detection sensitivity was estimated in six normal subjects, and compared with detection when the chest cage was strapped in the position of full expiration.
2. With chest cage restriction there was both a decrease in detection sensitivity and an increase in the willingness to report the presence of an added load to breathing.
3. This suggests that the similarity of detection in chest clamping and control previously reported was due partly to increased detection bias with chest clamping.
4. These results have implications concerning the dependence of detection on afferent information from the chest wall.