bluuebunny/crossref_metadata_2025_split huggingface dataset:
Renal response to atrial natriuretic factor in rats without intact papillae
Authors: Torikai Shozo 
Published: August 2015

1. In order to examine the contribution of renal papilla to atrial natriuretic factor (ANF)-induced diuresis, clearance studies were done in rats with intact papillae and bromoethylamine hydrobromide (BEA)-induced papillary necrosis.
2. Papillary necrosis did not attenuate the diuretic and natriuretic response to ANF. In a moderately hydropenic state, urine flow and fractional water excretion were rather more increased in papillary necrosis rats than in papilla-intact ones. In a volume-expanded state, both groups had a similar diuretic response to ANF.
3. Present data indicate that the existence of intact renal papilla is not essential for ANF-induced diuresis. Furthermore, it is suggested that absolute magnitude of ANF-induced diuresis may be dependent on its extrapapillary action(s).
A simple method for definition of incomplete suppression of aldosterone and its association with hypertension and hypokalaemia in man
Authors: Adam William R. 
Published: August 2015

1. By defining a model for control of potassium homoeostasis, patients with unexplained hypokalaemia may then be described as fitting or not fitting the model. Fitting the model implies an abnormality of known control mechanisms (e.g. aldosterone); by contrast, not fitting the model suggests other unknown factors responsible for the hypokalaemia and, possibly, hypertension.
2. In the presence of normal acid-base status, potassium excretion (Uκ+. V) is regulated by plasma potassium (Pκ+), delivery of sodium to the distal tubule and aldosterone secretion. A linear relationship (correlation coefficient of 0.72) was defined by:
U κ+ V/P κ+ = 5.1 × log(UAldoV) × log(Uκ+V) + 1.4
based on a 24 h urine collection and plasma sample, in 16 normal subjects, 50 hypertensive normokalaemic subjects and 11 patients with hyperaldosteronism.
3. The relationship was robust and held true for variations in dietary sodium and potassium intake (5–300 and 20–100 mmol/day respectively) and variations in aldosterone excretion produced by enalapril. Patients with abnormal renal potassium wasting due to known extraneous factors (n = 11) all fell outside the 95% confidence limits.
4. Twelve patients with hypertension and hypokalaemia and renal potassium wasting all fitted within the confidence limits, being no different from 22 controls selected on the basis of age and urinary potassium excretion (30–50 mmol/day). This suggests that in these 12 patients the hypokalaemia (but not necessarily the hypertension) was not due to ‘unknown’ steroids but rather lack of regulation of the controlling variable, aldosterone.
Vascular sensitivity to prostaglandin I2 and urinary excretion of 6-keto-prostaglandin F1α in conscious dogs
Authors: Jones Robert L. , Watson Michael L. 
Published: August 2015

1. A method is described for measuring the urinary excretion of 6-keto-prostaglandin F1α, the stable hydrolysis product of prostaglandin I2, by stable isotope dilution gas chromatography–mass spectrometry.
2. Three different doses of prostaglandin I2 were infused intravenously into conscious dogs and the effects on systemic and renal haemodynamics and urinary sodium excretion were observed.
3. The two highest infusion rates of prostaglandin I2 (15 and 30 ng min−1 kg−1 body weight) induced significant decreases in systematic blood pressure and dose-related increases in sodium excretion, but no change in renal haemodynamics.
4. There was a linear relationship between urinary excretion of 6-keto-prostaglandin F1α and the rate of infusion of prostaglandin I2.
5. The calculated basal rate of entry of prostaglandin I2 into the systematic circulation in conscious dogs is 4 ng min−1 kg−1 body weight, which is substantially higher than that previously reported in man.
Blood pressure in the puerperium
Authors: Walters B. N. J. , Thompson M. E. , Lee A. , De Swiet M. 
Published: August 2015

1. Blood pressure was measured by random zero sphygmomanometer in the morning and afternoon for 5 days after normal delivery in a group of 136 previously normotensive women. The number of women studied each day varied from 32 to 125.
2. The afternoon blood pressure was higher than the morning blood pressure (differences: 1.7 mmHg systolic, 2.6 mmHg diastolic; P &lt; 0.05).
3. Both systolic and diastolic blood pressures rose for the first 4 days after delivery. The average rise over the whole period was about 6 mmHg systolic and 4 mmHg diastolic (P &lt; 0.05).
4. A considerable number of previously normotensive women displayed elevations of blood pressure in the puerperium. Twelve per cent of all patients exceeded a diastolic blood pressure of 100 mmHg.
Smoking behaviour and personality patterns of smokers with low and high CO absorption
Authors: Nil Rico , Woodson Phillip P. , Bättig Karl 
Published: August 2015

1. The present experiment describes an attempt to select differentially nicotine dependent smokers by means of an objective and non-invasive measure of cigarette smoke CO absorption. Toward this goal the differences in expiratory tidal air CO concentration before and after smoking a single cigarette (tidal CO boost) were measured in three experimental sessions. The selection criteria were tidal CO boosts greater than 3.5 p.p.m. and less than 1 p.p.m. According to these criteria 19 out of 171 subjects were consistently found to be high CO absorbers and 20 were found to be low CO absorbers.
2. Puffing behaviour was measured throughout all three test sessions by the flowmeter method and respiratory inhalation by thorax impedance plethysmography. In addition, heart rate was continuously measured during smoking. These data were used to assess for specific differences between the two extremes of inhalation behaviour.
3. High CO absorbers differed from low CO absorbers by more intensive patterns of puffing and respiratory inhalation, by higher daily cigarette and coffee consumption, by lower alcohol consumption, by shorter latencies to the first cigarette in the morning, by greater subjective need for smoking and by lower scores for healthy eating habits. No intergroup differences were observed for smoking induced heart rate acceleration. The high CO absorbers were significantly older than the low CO absorbers; however, no evidence was found that any of the differences in smoking style between the two extremes might be related to their difference in age. No differences were seen in cigarette strengths, in personality or in coronary prone behaviour as assessed by means of standardized questionnaires in all subjects.
4. It is concluded that nicotine plays a more important role in smoking motivation among the high than among the low CO absorbing smokers. The role of nicotine and the individual dosage absorbed by the smokers, however, remain to be analysed further and are discussed in the light of nicotine tolerance effects.
A test of the validity of the lithium-marker technique for monitoring dietary sources of salt in man
Authors: Sanchez-Castillo C. P. , Branch W. J. , James W. P. T. 
Published: August 2015

1. A lithium-tagged salt for assessing the sources of salt in the human diet was prepared by fusing lithium carbonate and sodium chloride at 900°C followed by grinding and sieving the fused salts to a defined grain size; magnesium carbonate was added as a hygroscopic agent.
2. To validate the use of this tagged salt, which replaced alternately table salt and cooking salt in daily use, a 44 day metabolic study was conducted on five volunteers. Measurements of sodium and lithium balance throughout the study showed that 93% of both dietary sodium and dietary lithium were excreted in the urine and 1.7% of dietary lithium and 2% of dietary sodium in the faeces. Collections of sweat for 48 h at intervals throughout the study showed that only 1.7% of dietary lithium and 1.4% of dietary sodium were recovered in sweat. Thus both elements were excreted equivalently by the three main routes. The apparent mean sodium retention over the whole period of dietary control was 7.4 ± 4.4 mmol/day or 3.4% of the total intake.
3. The excretory patterns of lithium after a period of lithium ingestion were exponential, thus allowing a method to be developed for the prediction of total lithium output from a shorter period of urine collection.
4. This study suggests that the lithium method is suitable for epidemiological use to measure the sources of dietary salt.
Effect of acute ethanol administration on the baroreceptor reflex control of heart rate in normotensive human volunteers
Authors: Abdel-Rahman A.-R. A. , Merrill R. H. , Wooles W. R. 
Published: August 2015

1. The effects of acute ethanol administration on blood pressure, heart rate and the baroreceptor reflex control of heart rate were studied in normotensive subjects who served as their own control. Baroreceptor reflex control of heart rate was measured by two methods: the ramp method and the steady state method.
2. None of the doses of ethanol had any effect on blood pressure during the observation period, except for the highest dose where a slight elevation was evident for a short period of time. On the other hand, the heart rate showed a slight but consistent dose-related increase.
3. In general, ethanol attenuated the baroreceptor mediated bradycardia but this effect was dependent on the way in which blood presure was elevated. A dose-related impairment of baroreceptors was evident when the ramp method was used, i.e. ethanol significantly depressed baroreflex sensitivity, expressed as Δheart period (HP)/Δmean arterial pressure (MAP). In contrast, ΔHP/ΔMAP was not influenced by ethanol when the steady state method was used. However, the steady state baroreflex curves were reset about a higher median blood pressure (MAP50), suggesting that the baroreceptors will be operative at higher blood pressure levels after ethanol.
4. The pressor responsiveness was also influenced differently by ethanol depending on the method of injecting phenylephrine. An increase in pressor responsiveness was evident, though not dose-related, after ethanol only when blood pressure was elevated by the ramp method, suggesting that the inverse relationship between baroreflex sensitivity and pressor responsiveness is more prominent with the ramp method and/or when impairment rather than resetting of baroreceptors occurs.
5. That the decrease in baroreflex sensitivity and the increase in MAP50 were related to peak ethanol levels in blood and that the blood pressure was not influenced by ethanol strongly suggest these effects were ethanol mediated. The weakened buffering action of the baroreflexes would be expected to favour the development of higher blood pressure.
Aldosterone responsiveness to metoclopramide in hyperprolactinaemia
Authors: O'Malley B. P. , Mercey D. , Clarke E. , Maguire M. , Jackson J. , Rosenthal F. D. 
Published: August 2015

1. Basal serum aldosterone levels in 13 hyperprolactinaemic females did not differ significantly from those of nine control individuals.
2. There was increased responsiveness of circulating aldosterone levels to the long acting dopamine antagonist metoclopramide (10 mg intravenously) in the hyperprolactinaemic patients as compared with the controls.
3. Prolactin responsiveness to metoclopramide was reduced in the patients as compared with the controls, such being considered characteristic of a prolactinoma.
4. Basal serum thyrotrophin (TSH) levels, although within the euthyroid range, were increased in the patients as compared with the controls. There was no significant difference in the TSH responsiveness to metoclopramide between the study groups. However, in the five patients with exaggerated responses of TSH to metoclopramide, basal TSH levels were significantly higher than in the other patients.
5. One explanation for these results is that prolactin can directly or indirectly modulate the aldosterone response to metoclopramide.
Na+, K+ and water balance in young spontaneously hypertensive rats: relationship to blood pressure after high K+ treatment
Authors: Sugden A. Louise , Bean Barbara L. , Straw James A. 
Published: August 2015

1. These studies were designed to investigate the effects of high dietary K+ on electrolyte and water balance in young spontaneously hypertensive rats (SHR) and to relate these effects to changes in blood pressure.
2. The high K+ diet reduced blood pressure by approximately 10 mmHg during the development of hypertension. Blood pressure, however, plateaued at the same maximum level as control by age 13 weeks.
3. Rats fed the high K+ diet showed a significant increase in water intake and urine volume throughout the treatment period but no change in plasma volume or extracellular fluid volume occurred.
4. A slight natriuresis was also observed in rats on the high K+ diet, but this was not of sufficient magnitude to decrease total body Na+.
5. These results confirm previous findings that K+ causes a diuresis and a natriuresis, but demonstrate that the diuretic action of K+ cannot explain its antihypertensive properties in young SHR.
Carnitine acyltransferases and acyl-CoA hydrolases in human and rat liver
Authors: Agius L. , Wright P. D. , Alberti K. G. M. M. 
Published: August 2015

1. The activities of carnitine acyltransferases and acyl-CoA hydrolases were determined in human and rat liver to establish the validity of extrapolating from studies on rats to human metabolism.
2. In human liver, carnitine acetyltransferase activity was 10–14 times higher and carnitine octanoyltransferase 1.7–2.4 times higher than in rat liver, while carnitine palmitoyltransferase activity was similar in human and rat.
3. Acetyl-CoA hydrolase and octanoyl-CoA hydrolase activities were lower in human (42–57%) than in rat liver, but palmitoyl-CoA hydrolase activity was similar in both species.
4. The activity of citrate synthase was lower (44%) in human than in rat liver. The low citrate synthase activity and the high carnitine acetyltransferase in human liver suggest that in man acetylcarnitine might be more important as a vehicle for export of acetyl units from mitochondria than citrate.
5. The high activity of carnitine acetyltransferase in human liver is consistent with the observation that acetylcarnitine is the predominant acylcarnitine excreted in diabetic ketosis in man.
6. It is concluded that the rat may not be a valid model for carnitine metabolism in man, and that in human liver carnitine may have an important role in transfer of acetyl groups out of mitochondria and possibly also to extrahepatic tissues.
Effects of sodium replacement on uptake of the dipeptide glycylsarcosine by hamster jejunum in vitro
Authors: Burston D. , Matthews D. M. 
Published: August 2015

1. We report observations on transport of the hydrolysis-resistant dipeptide glycylsarcosine by rings of everted hamster jejunum in vitro in the presence and absence of Na+, using several substituents for Na+: Li+, K+, Cs+, Tris, choline and mannitol.
2. At most concentrations, mediated influx of glycylsarcosine was depressed by Li+, K+, Cs+ and Tris, though not abolished. At high concentrations, it was moderately increased by choline and mannitol. Under conditions in which the tissue could concentrate the peptide in the presence of Na+, uptake was greatly depressed by all the substituents and the ability to concentrate was abolished.
3. The Kt of mediated influx was affected in different ways according to the substituent used. Kt was reduced by Li+ replacement of Na+ and increased by choline replacement. Vmax. was greatly reduced by all metallic substituents but not by non-metallic substituents.
4. Though the results cannot yet be satisfactorily interpreted, they suggest possible reasons for previous conflicting results and show that it is impossible to make the unqualified statement that transport of glycylsarcosine is ‘Na+-dependent’. It is now doubtful whether transport of this peptide into the intestinal cells is by co-transport with Na+, and the whole matter of Na+-dependence of intestinal peptide transport is in question.
Free d-amino acids in human plasma in relation to senescence and renal diseases
Authors: Nagata Yoko , Akino Toyoaki , Ohno Kimiyoshi , Kataoka Yoshimitsu , Ueda Takahiro , Sakurai Tetsuo , Shiroshita Koh-Ichi , Yasuda Takuji 
Published: August 2015

1. Minute but appreciable amounts of d-amino acids were detected in normal human plasma.
2. The content was significantly higher in an elderly population (age 76 ± 6 years, mean ± sd, n = 41) than in a younger group (age 42 ± 4 years, n = 26), i.e. 6.9 ± 4.8 nmol/ml (mean ± sd, range 0–18.8 nmol/ml) and 2.5 ± 1.8 nmol/ml (range 0–6.3 nmol/ml) for the elderly and the younger groups, respectively.
3. Elevation of plasma d-amino acid level was observed in a group of patients with renal disease (3.6–52.6 nmol/ml), in proportion to the serum level of creatinine (n = 50, r = 0.726, P &lt; 0.001), β2-microglobulin (n = 34, r = 0.551, P &lt; 0.005), and to glomerular filtration rate (n = 39, r = 0.556, P &lt; 0.001).
Multifactorial evaluation of blood pressure fall upon hospitalization in essential hypertensive patients
Authors: Nishimura Hikaru , Nishioka Akinori , Kubo Shinichiro , Suwa Michihiro , Kino Masaya , Kawamura Keishiro 
Published: August 2015

1. Studies were prospectively performed on 72 hospitalized patients with essential hypertension. Blood pressure was normalized within 1 week of admission in 33 patients (group I), but did not decrease in 39 patients (group II). To determine the factors that differentiate group I from group II, cardio-renal haemodynamic and endocrinological indices were evaluated using multivariate analysis.
2. Systolic, diastolic and mean blood pressures on admission were higher in group II (P &lt; 0.001), whose optic fundi showed more severe changes (P &lt; 0.001). Although group II had greater left ventricular posterior wall thickness (P &lt; 0.02), left ventricular mass index (P &lt; 0.05) and systemic vascular resistance (P &lt; 0.01) on echocardiography, their cardiac index and ejection fraction were comparable with those of group I.
3. Renal blood flow (P &lt; 0.05) and glomerular filtration rate (P &lt; 0.01) were lower in group II than in group I. Renal vascular resistance was more elevated (P &lt; 0.01) in group II than in group I.
4. After severe sodium depletion and ambulation, group I showed a greater increase in plasma noradrenaline and adrenaline (P &lt; 0.05). On multivariate analysis, those with lower systolic blood pressure, better renal function and more reactive sympathetic nervous system were discriminated as group I.
5. These data suggest that group I patients have lower systolic blood pressure on admission, greater sympathetic reactivity and better renal function, all of which contribute to their spontaneous blood pressure fall after admission.
Deferoxamine-induced bone changes in haemodialysis patients: A histomorphometric study
Authors: Charhon Sam A. , Chavassieux Pascale , Boivin Georges , Parisien May , Chapuy Marie-Claire , Traeger Jules , Meunier Pierre J. 
Published: August 2015

1. The histological effects of deferoxamine therapy were assessed on transiliac bone biopsies taken after double tetracycline labelling from 16 uraemic patients undergoing chronic haemodialysis, all having aluminium deposits in bone. Eight patients had osteomalacia, five had an ‘aplastic’ bone lesion and three a high bone turnover with a marked increase in osteoid volume.
2. Deferoxamine was administered intravenously once a week at doses ranging from 1 to 6 g for a mean duration of 7.6 ± 3.3 (sd) months.
3. Deferoxamine therapy was associated with significant reductions in stainable aluminium deposits, osteoid volume, osteoid surfaces and thickness index of osteoid seams. The osteoblastic osteoid surfaces as well as the bone formation rates also increased significantly.
4. A rise in resorption parameters and in serum parathyroid hormone levels was observed in patients with osteomalacia. The percentage reductions in stainable aluminium and in osteoid volume were correlated with the degree of hyperparathyroidism.
5. These data show that deferoxamine therapy reduces stainable bone aluminium and improves bone mineralization in low turnover osteomalacia and that the presence of hyperparathyroidism is associated with an increased response to deferoxamine therapy.
Influence of fasting on leucine and muscle protein metabolism across the human forearm determined using l-[1-13C,15N]leucine as the tracer
Authors: Cheng K. N. , Pacy P. J. , Dworzak F. , Ford G. C. , Halliday D. 
Published: August 2015

1. We have used l-[1-13C,15N]leucine as the substrate tracer to study leucine and muscle protein metabolism across the forearm of eight normal fasting adults.
2. The rates of protein synthesis and breakdown, de- and re-amination of leucine, and the oxidative de-carboxylation of its keto acid were calculated directly from the arteriovenous metabolite balances and isotope dilutions as described by the metabolic model.
3. The results were compared with those obtained previously when subjects were fed. The effects of fasting on protein and leucine metabolism were a significant decrease in protein synthesis from 127 (sem 11; n = 6) to 70 (sem 6; n = 12) nmol of leucine min−-1 100 ml−-1 of forearm tissue (P &lt; 0.001) and a marked decrease in leucine catabolism in the forearm muscle.
4. This model has demonstrated that each subject was in negative protein balance across the forearm during fasting while positive during feeding, the mean values being −29(sem 5; n = 12) and + 39(sem 9; n = 6) nmol of leucine min−-1 100 ml−-1 of forearm tissue respectively.
5. These results are sufficiently encouraging to suggest a role for this model in future studies on muscle protein metabolism.
Influence of the sympathetic nervous system and vasopressin on the blood pressure lowering effect of nifedipine in deoxycorticosterone acetate–salt hypertensive rats
Authors: Takata Yutaka , Yamashita Yoshiaki , Takishita Shuichi , Fujishima Masatoshi 
Published: August 2015

1. The role of the sympathetic nervous system and the effect of vasopressin (AVP) on the hypotensive action of nifedipine (Nf) were evaluated in conscious, unrestrained normotensive and DOCA–salt hypertensive rats.
2. The hypotensive response to Nf was much greater in DOCA rats than in the controls.
3. Solitary blockade of the sympathetic nervous system or AVP, did not alter the Nf effect in either DOCA or control rats. However, a combination clearly diminished the effect of Nf in the DOCA group, but enhanced it in the controls. The inhibition of angiotensin II (ANG II) augmented the hypotensive effect of Nf in control animals, but not in the DOCA rats. The percentage fall in blood pressure with Nf was much the same in both groups after the combined inhibition of the sympathetic nervous system and AVP.
4. The enhanced hypotensive action of Nf in DOCA rats may be dependent on the hyperactivity of the sympathetic nervous system and AVP, which facilitates calcium influx, and in the normotensive animals the depressor response to Nf may relate to blockade of the calcium influx, independent of the sympathetic nervous system, AVP and ANG II.
Time course of end-expired carbon monoxide concentration is important in studies of cigarette smoking
Authors: Woodman G. , Wintoniuk D. M. , Taylor R. G. , Clarke S. W. 
Published: August 2015

1. Fifteen asymptomatic habitual smokers each smoked one of their usual cigarettes, not having smoked for 2 h. End-expired carbon monoxide concentration (EECO) was measured with an Ecolyzer 2000 series analyser before smoking (pre-S value), 1 min after finishing smoking (post-S value) and then at intervals up to 1 h.
2. The mean EECO boost (increase) over all subjects declined biphasically after smoking, with an initial fast phase from 1 to 5 min, and then a slow phase from 5 to 60 min. EECO fell by as much in the first 5 min as in the next hour.
3. Post-S EECO was related to pre-S EECO (r = 0.89, P &lt; 0.001), but EECO boost was not related to pre-S (r = 0.00). EECO boost was unaffected by the sampling manoeuvre.
4. EECO measurements in epidemiological and smoking studies should not be made for at least 5 min after a cigarette is finished