bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Possible Role for Protein Kinase C in the Regulatory Differences between Intra-Abdominal and Subcutaneous Human Adipose Tissue
Authors: Vikman Hanna-Leena , Kaartinen Johanna M. , Tuominen Raimo K. , Ohisalo Jorma J. 
Published: August 2015

1. The adenosine A1-receptor agonist N6-(phenylisopropyl)adenosine inhibited lioplysis in a dose-dependent manner in human adipocytes. The effect is mediated by the inhibitory guanine-nucleotide-binding protein(s) that can be phosphory-lated and thereby inactivated by protein kinase C.
2. Stimulation of protein kinase C by 12-O-tetradecanoyl-phorbol-13-acetate attenuated the inhibitory effect of the adenosine agonist.
3. Omental fat cells are less sensitive to adenosine than subcutaneous cells, although the stimulatory arm of cyclase regulation appears normal. Protein kinase C activity was measured in the soluble and particulate fractions of human omental and subcutaneous adipose tissue. Omental adipose tissue had a twofold higher membrane-bound and a threefold higher soluble protein kinase C activity.
4. It is therefore possible that the differences in regulation between the two sites are caused by different C kinase activities, causing variable phosphorylation of the inhibitory guanine-nucleotide-binding protein(s).
Responses of Tissue Protein Synthesis to Nutrient Intake in Rats Exposed to Interleukin-1β Or Turpentine
Authors: Ballmer Peter E. , McNurlan Margaret A. , Grant Ian , Garlick Peter J. 
Published: August 2015

1. The influence of an acute-phase reaction on the ability of protein synthesis rates in liver and three different muscles (gastrocnemius, soleus and heart) to respond to a short intravenous infusion of nutrients (glucose plus amino acids) was investigated during experimental inflammation induced by injection of human recombinant interleukin-1β or turpentine in young male rats.
2. Interleukin-1β induced a consistent increase of 3°C in body temperature between 3 and 5 h after injection, whereas turpentine induced a delayed fever, peaking by 13 h.
3. Interleukin-1β and turpentine stimulated fractional rates of protein synthesis in liver. The synthesis rate was inhibited by interleukin-1β in gastrocnemius and soleus muscle, but an elevation was seen in heart muscle. In this study there was no significant response of muscle to turpentine injection.
4. Two hours of parenteral nutrition increased fractional synthesis rates in all tissues when compared with Ringer's lactate. Somewhat larger responses to feeding were observed as a result of either interleukin-1β or turpentine injection in all tissues, but these improvements were not significant.
5. We conclude that the response of protein synthesis rates in liver and skeletal muscle to parenteral nutrition is not inhibited, and may be somewhat enhanced, during acute inflammatory conditions in the growing rat.
Effects of Acid Loading on Serum Amino Acid Profiles and Muscle Composition in Normal Fed Rats
Authors: Cupisti A. , Baker F. , Brown J. , Lock C. , Bevington A. , Harris K. P. G. , Walls J. 
Published: August 2015

1. Impaired body growth, loss of lean body mass and negative nitrogen balance are common findings in chronic renal failure. Enhanced endogenous protein catabolism in skeletal muscle induced by co-existent metabolic acidosis seems to be an important aetio-logical factor.
2. In uraemic patients abnormalities in blood amino acid profiles are present after a protein meal, suggesting impaired metabolism of ingested proteins.
3. This study demonstrates that acidosis induces changes in arterial amino acid profiles in fed non-uraemk rats. These included increased levels of threonine, histidine, proline, serine and glycine, and decreased levels of tryptophan. These changes are similar to those found in uraemic patients after a protein meal, suggesting a pathogenic role of acidosis in the impairment of exogenous protein metabolism.
4. Intracellular amino acid levels in the muscle tissue partly reflect the changes in the extracellular level.
5. Acidotic animals had a decreased body weight gain and a reduced alkali-soluble protein/DNA ratio in muscle cells compared with controls.
6. In conclusion, the results show that acidosis per se modifies the circulating amino acid profile in fed rats, resulting in a pattern similar to the post-prandial amino acid changes described in uraemic patients. These abnormalities occur together with impaired growth of skeletal muscle cells.
Changes in Renal Function in Acute Experimental Pancreatitis in Rats: A Therapeutic Role for Somatostatin
Authors: González-Rubio M. , García-Escribano C. , Díez-Marqués M. L. , Arribas I. , Martínez-Onsurbe P. , Rodríguez-Puyol M. , Rodríguez-Puyol D. 
Published: August 2015

1. The present study was designed to determine the changes in renal function in two models of experimental pancreatitis in rats, in an attempt to assess the possible pathogenic role of reactive oxygen species and to elucidate a possible therapeutic role for somatostatin.
2. Mild pancreatitis was induced by low blockade of the biliary duct and severe pancreatitis was evoked by retrograde infusion of bile salts. Renal function was studied by clearance techniques in rats with pancreatitis, treated or not treated with somatostatin. Plasma and glomerular malonyldialdehyde levels were measured by the thiobarbituric acid method.
3. Renal function did not change in rats with low blockade of the biliary duct, but animals receiving a retrograde infusion of bile salts showed a significant decrease in glomerular filtration rate and renal plasma flow with respect to sham-operated animals.
4. Plasma malonyldialdehyde levels increased significantly in rats treated with bile salts with respect to control animals, whereas no changes were detected in glomerular malonyldialdehyde levels. Thus, the renal dysfunction does not seem to be related to an increased production of reactive oxygen metabolites at the glomerular level.
5. Somatostatin infusion significantly improved renal function in rats with severe pancreatitis (retrograde infusion of bile salts) by increasing glomerular filtration rate, renal plasma flow and filtration fraction. These results support a possible therapeutic role for somatostatin in the renal dysfunction associated with the severe forms of pancreatitis.
Brisk Walking and Serum Lipoprotein Variables in Formerly Sedentary Men Aged 42–59 Years
Authors: Stensel D. J. , Hardman A. E. , Brooke-Wavell K. , Vallance D. , Jones P. R. M. , Norgan N. G. , Winder A. F. 
Published: August 2015

1. The purpose of this study was to examine the influence of brisk walking on serum lipoprotein variables.
2. Seventy-two apparently healthy but physically inactive men (aged 42–59 years) were recruited. These men were normotensive non-smokers without a history of dyslipidaemia. Subjects were randomly allocated on a 2 to 1 basis into either a walking group (n = 48) or a control group (n = 24). Walkers followed a self-monitored programme of brisk walking for 1 year, whereas control subjects maintained their habitual lifestyle.
3. Treadmill walking tests were conducted to examine changes in fitness. Concentrations of serum lipids and lipoproteins were determined in fasting subjects. The amount of body fat was measured by body density. Circumferences at the waist and hip and skinfold thicknesses were used to determine the distribution of body fat. Dietary intakes were assessed by weighed food inventories.
4. Seven subjects (six walkers and one control subject) dropped out during the study. Walkers did an average of 28 (SEM 1.4; n = 42) min of brisk walking/day. This improved endurance fitness but did not influence serum concentrations of total cholesterol, high-density lipoprotein cholesterol, triacylglycerol, apolipoprotein A-1, apolipoprotein B or lipoprotein (a). Neither body mass nor the amount of body fat changed, relative to control subjects.
5. These data suggest that brisk walking does not modify lipoprotein metabolism in normolipidaemic middle-aged men.
Effects of Haemodialysis and Continuous Ambulatory Peritoneal Dialysis on Abnormalities of Ion Transport in vivo in Patients with Chronic Renal Failure
Authors: Brearley Christopher J. , Aronson Jeffrey K. , Boon Nicholas A. , Raine Anthony E. G. 
Published: August 2015

1. We have studied Na+/K+ pump activity in vivo in three groups of subjects: patients with chronic renal failure not receiving maintenance dialysis, patients being treated by either haemodialysis or continuous ambulatory peritoneal dialysis, and matched control subjects.
2. To do this we have measured the changes in plasma and intraerythrocytic rubidium concentrations after an oral load of rubidium chloride, having previously shown that changes in the disposition of rubidium measured in this way reflect changes in the activity of the Na+/K+ pump in vivo.
3. Erythrocyte rubidium uptake was significantly reduced both in ten patients with chronic renal failure not receiving maintenance dialysis and in 12 patients being treated by haemodialysis, when compared with 31 healthy control subjects. In contrast, erythrocyte rubidium uptake was not altered in 13 patients treated by continuous ambulatory peritoneal dialysis. There was also a significantly reduced rate constant for erythrocyte rubidium uptake in patients with undialysed chronic renal failure (0.66 h−1) and in those treated by haemodialysis (0.78 h−1), whereas in patients treated by continuous ambulatory peritoneal dialysis the rate constant for erythrocyte rubidium uptake was not significantly different from control values (1.36h−1 and 1.41 h−1, respectively).
4. These findings are consistent with a reversal of the inhibition of erythrocyte Na+/K+ pump activity in vivo found in chronic renal failure by continuous ambulatory peritoneal dialysis, but not by haemodialysis. This difference may be due to the failure of haemodialysis to clear a circulating inhibitor of Na+, K+-ATPase or to the rapid re-accumulation of such an inhibitor after haemodialysis. Alternatively, it could be due to a dialysable inhibitor of potassium efflux, with a secondary reduction in the activity of the Na+/K+ pump.
5. Neither continuous ambulatory peritoneal dialysis nor haemodialysis reversed the abnormal disposition of rubidium in the plasma found in undialysed patients. This suggests that the putative inhibitor which accumulates in chronic renal failure does not affect cation transport in all tissues of the body, and that abnormalities of cation transport in chronic renal failure may be due to more than one mechanism.
Glucose Turnover in Pregnant Women with Acute Malaria
Authors: Davis T. M. E. , Suputtamongkol Y. , Spencer J. L. , Wilson S. G. , Mekhton S. , Croft K. D. , White N. J. 
Published: August 2015

1. Hypoglycaemia is a serious complication of falciparum malaria, especially in pregnant patients. To investigate malaria-associated changes in glucose metabolism in pregnancy, steady-state [6,6-2H2] glucose turnover and clearance were measured in 10 women (eight with uncomplicated falciparum malaria and two with vivax malaria at 16–30 weeks gestation) before treatment, after intravenous quinine infusion (patients with falciparum malaria) and in convalescence.
2. Admission basal plasma glucose concentrations were higher than those in convalescence [median (range); 4.8 (3.6-7.0) versus 4.0 (3.6-4.6) mmol/l, P = 0.02], and there was a significant fall during initial quinine treatment in patients with falciparum malaria [5.0 (4.3-7.6) to 3.6 (3.2-5.4) mmol/l, P &lt;0.01]. Basal plasma insulin levels were comparable at presentation and follow-up (P = 0.35) and rose an average of only 2 m-units/l during quinine infusion (P &lt;0.05). Pretreatment glucose turnover rates [3.37 (2.57-4.16) mgmin−1 kg−1] were comparable with those found in a previously reported study of non-pregnant severely ill patients [3.22 (2.12-4.82) mg min−1 kg−1, n = 11] and correlated significantly with the admission parasitaemia (P &lt;0.025). In the eight patients with falciparum malaria, there was a significant fall in turnover during intravenous quinine infusion [3.42 (238-4.16) to 2.66 [1.94-3.94) mgmin−1 kg−1] whereas clearance did not change significantly. In convalescence, turnover values showed a wide scatter, although the highest values (3.34-4.33 mgmin−1 kg−1) were in patients studied within 4 days of presentation (two patients) or with pre-eclampsia (one patient); values for glucose clearance were consistently higher than those at presentation (P = 0.004).
3. Given the simultaneous plasma glucose and insulin concentrations, these results suggest that the combination of pregnancy and severe malaria may result in greater initial glucose requirements than in severely ill but non-pregnant patients, that there is a largely insulin-independent reduction in glucose production and utilization during quinine therapy which may partly reflect attenuated parasite glycolysis, and that early convalescence in pregnant women may be associated with higher glucose utilization than that in non-pregnant patients.
Contractile Dysfunction in the Diabetic-Rat Heart is An Intrinsic Abnormality of the Cardiac Myocyte
Authors: Okayama Hideki , Hamada Mareomi , Hiwada Kunio 
Published: August 2015

1. In order to clarify whether the myocardial dysfunction observed in diabetic-rat hearts is an intrinsic property of the myocytes or not, we investigated cardiac function and myocyte contractile function in diabetic rats 5 weeks after the injection of streptozotocin.
2. Maximal and minimal dP/dt and time constant of isovolumic pressure fall were measured using a micromanometer in diabetic and age-matched control rats.
3. Isolated myocytes were enzymically obtained from each rat heart and were stimulated at 1 Hz (37°C) in a buffer containing 1.5 mmol/l Ca2+. The images of myocyte contractions were recorded by a video system. Normalized maximal velocity of shortening (maximal velocity of cell shortening/resting cell length; s−1), normalized maximal velocity of relengthening (maximal velocity of cell relengthening/resting cell length; s−1) and extent of shortening [(twitch amplitude/resting cell length) × 100;%] were analysed by a digitalized computer as contractile functions of the myocyte.
4. The maximal and minimal dP/dt in diabetic rats (7876, 5341 mmHg/s) were significantly lower than those in control rats (9349, 7876 mmHg/s). The time constant of isovolumic pressure fall in diabetic rats (12.7 ms) was significantly greater than that in control rats (8.6 ms). Moreover, the normalized maximal velocity of shortening, normalized maximal velocity of relengthening and extent of shortening in myocytes from diabetic rats (1.40 s−1, 1.38 s−1, 9.5%) were significantly lower than those in myocytes from control rats (1.64 s−1, 1.60 s−1, 11.8%).
5. These results suggest that contractile impairment in this diabetic-rat heart model is mainly due to an intrinsic abnormality of the cardiac myocytes.
Platelet Membrane Microviscosity in Sabra Rats with Early Salt Hypertension
Authors: Sang Kim Hanh Le Quan , Kunes Jaroslav , Zicha Josef , Lacour Bernard , Ben-Ishay Drori , Devynck Marie-Aude 
Published: August 2015

1. To investigate the possibility that arterial hypertension is associated with changes in the physicochemical properties of cell membranes, we have studied the effects of dietary salt loading on platelet membrane microviscosity in hypertension-prone and -resistant Sabra rats.
2. Sixteen hypertension-prone and 14 hypertension-resistant Sabra rats were submitted to either a low-salt (0.25% NaCl) or a high-salt (4% NaCl) diet for 3–4 weeks. Platelet membrane anisotropy was determined, in the presence and absence of extracellular Na+, using two fluorescent probes, diphenylhexatriene and trimethylamino-diphenylhexatriene, inserted in different areas of the cell membranes.
3. A decrease in diphenylhexatriene anisotropy was demonstrated when platelets of hypertension-prone (but not hypertension-resistant) Sabra rats were suspended in a Na+-free medium. This alteration in membrane dynamic properties is localized within the hydrophobic core of the platelet membranes and is independent of salt intake. It reflects an abnormal fluidizing effect of extracellular Na+ removal.
4. Platelets of hypertension-prone and hypertension-resistant Sabra rats did not differ significantly in trimethylamino-diphenylhexatriene fluorescence anisotropy, irrespective of the incubation media used. Extracellular Na+ removal caused an increase in trimethylamino-diphenylhexatriene fluorescence anisotropy in all groups, the change being greatest in salt-loaded rats.
5. This study indicates that platelet membrane microviscosity is specifically altered in the hypertension-prone Sabra rat irrespective of salt intake. This raises the question of the relation of this inherited defect with the susceptibility of this strain to dietary salt loading.
Plasma Levels of 5-Hydroxytryptamine during Sympathetic Stimulation and in Raynaud's Phenomenon
Authors: Coffman Jay D. , Cohen Richard A. 
Published: August 2015

1. The involvement of plasma 5-hydroxytryptamine in normal subjects during sympathetic stimulation and in patients with Raynaud's phenomenon was studied.
2. Arterial and venous plasma levels of 5-hydroxytryptamine were measured in normal subjects in a warm room, during reflex sympathetic stimulation by body cooling and during intra-arterial infusions of tyramine. Normal subjects (n = 19) had significantly higher levels of 5-hydroxytryptamine in venous plasma [mean 1.42 (SEM 0.23) ng/ml] than in arterial plasma [0.67 (0.12) ng/ml; P &lt; 0.01]. Body cooling (n = 10) or tyramine infusion (n = 8) did not increase venous levels of 5-hydroxytryptamine despite significant decreases in blood flow and increases in vascular resistance.
3. Venous plasma levels of 5-hydroxytryptamine were also determined in patients with primary Raynaud's phenomenon (n = 12) or secondary Raynaud's phenomenon due to scleroderma (n = 11). Patients with primary or secondary Raynaud's phenomenon did not have significantly higher venous plasma levels of 5-hydroxytryptamine than normal subjects, even during vasospastic attacks (n = 3).
4. It is concluded that either 5-hydroxytryptamine is not involved in sympathetic nerve vasoconstriction or in Raynaud's phenomenon, or 5-hydroxytryptamine released in the microcirculation is largely taken up or metabolized by endothelial cells or platelets.
Effects of Nitric Oxide Inhibition on the Renal Papillary Blood Flow Response to Saline-Induced Volume Expansion in the Rat
Authors: Atucha Noemí M. , Ramírez Ana , Quesada Tomás , García-Estañ Joaquán 
Published: August 2015

1. Evidence indicates that nitric oxide (NO) exerts a paracrine influence in the renal medulla. Increases in papillary blood flow are thought to be an important determinant of the renal response to extracellular volume expansion. Therefore, in the present study, we have evaluated the role of NO in mediating papillary blood flow (laser-Doppler flowmetry) and excretory responses to volume expansion with isotonic saline (3% body weight, 15 min).
2. Infusion of the NO synthesis inhibitor Nω-nitro-l-arginine methyl ester (10 μg min−1 kg−1), significantly attentuated the renal diuretic and natriuretic responses to volume expansion as well as the renal hydrostatic interstitial pressure increase induced by this manoeuvre. The percentages of the water and sodium excreted in 1 h by the Nω-nitro-l-arginine methyl ester-pretreated animals were 36% and 40% of the load, whereas those of the control animals were 44% and 65%, respectively.
3. In similar experiments performed in the exposed papilla of Munich Wistar rats, the same dose of Nω-nitro-l-arginine methyl ester reduced basal papillary blood flow and blunted the elevation in papillary blood flow induced by volume expansion (6% versus 16% in the control animals).
4. These results indicate that the inhibition of NO synthesis blunts the renal excretory and papillary responses to volume expansion, suggesting that NO modulates these responses through changes in papillary blood flow and renal interstitial hydrostatic pressure.
Non-Respiratory Components of Heart Rate Variability in Heart Transplant Recipients: Evidence of Autonomic Reinnervation?
Authors: Bernardi Luciano , Valle Felice , Leuzzi Stefano , Rinaldi Mauro , Marchesi Eugenia , Falcone Colomba , Martinelli Luigi , Viganó Mario , Finardi Giorgio , Radaelli Alberto 
Published: August 2015

1. Although the high-frequency fluctuations in R—R interval (respiratory sinus arrhythmia) observed in heart transplant recipients are not a reliable marker of reinnervation because of a previously shown direct mechanical effect of breathing, the presence of a non-respiration-related low-frequency oscillation reflects rhythms generated outside the heart, and thus could be neurally mediated.
2. To evaluate the presence of reinnervation, the spontaneous variability in R—R interval was investigated, supine and after passive tilting, in 23 heart transplant recipients (age 43 years, range 23–64 years) and in 25 normotensive control subjects by autoregressive spectral analysis of low- and high-frequency spontaneous fluctuations in R—R interval and respiration. The response of R—R interval to amyl nitrite inhalation was also evaluated in five heart transplant recipients and eight control subjects.
3. Detectable low-frequency oscillations, unrelated to respiration, were present in 13/23 heart transplant recipients, particularly in those who were transplanted at least 20 months earlier (11/14). The natural logarithm of the power of low-frequency fluctuations was markedly lower than in control subjects (0.75 ± 0.21 versus 5.62 ± 0.20 ms2, P &lt; 0.001). The low-frequency but not the high-frequency fluctuations correlated with time since transplantation (r = 0.44, P &lt; 0.05). The subjects with low-frequency fluctuations showed a sudden decrease in R—R interval with amyl nitrite linearly related to the decrease in mean blood pressure (r ≧ 0.94). The slopes obtained in these heart transplant recipients were comparable (although of lower values) with those obtained in control subjects. The subjects with no low-frequency fluctuations showed no change in R—R interval despite a similar reduction in blood pressure.
4. Twenty months after transplantation signs of functional (reflex) reinnervation can be found in most heart transplant recipients.