bluuebunny/crossref_metadata_2025_split huggingface dataset:
AN APPRAISAL OF THE EFFECTS OF USUAL VS RECENT ALCOHOL INTAKE ON BLOOD PRESSURE
Authors: Puddey I. B. , Jenner D. A. , Beilin L. J. , Vandongen R. 
Published: June 2007

SUMMARY1. In a population‐based study of 343 men from two public utilities, 260 subjects reported drinking alcohol at least once a week. In these subjects a comparison was made of the relative effects on blood pressure of either their usual alcohol intake (assessed from a 7‐day retrospective diary) or recent alcohol intake (alcohol consumed at the last drinking session in the 24 h prior to blood pressure measurement).2. Both usual and recent alcohol intake showed similar correlations with level of blood pressure (BP). After adjustment of BP for the potential confounding influences of body mass index, age and smoking status, systolic and diastolic BP remained highest in those subjects with the highest reported levels of both usual and recent alcohol intake.3. In regression analyses comprising only those subjects who reported drinking in the 24 h before BP measurement, a 3–4 fold greater effect of usual rather than recent intake on both systolic and diastolic BP was predicted from the b coefficients. Regression analysis also demonstrated that the relationship between usual alcohol intake and BP was independent of recent intake, while the relationship between recent intake and BP was no longer significant when usual alcohol intake was entered into the regression equation.4. These observations suggest that consistent regular drinking is a more important determinant of the alcohol/BP relationship than intake in the previous 24 h.
EFFECT OF PURE EICOSAPENTAENOIC ACID FEEDING ON BLOOD PRESSURE AND VASCULAR REACTIVITY IN SPONTANEOUSLY HYPERTENSIVE RATS
Authors: Yin K. , Croft K. D. , Beilin L. J. 
Published: June 2007

SUMMARY1. This study examined the effects of eicosapentaenoic acid (EPA) treatment on vascular reactivity and blood pressure in spontaneously hypertensive rats (SHR).2. Twenty SHR were given pure EPA as the methyl ester (280 mg/kg) by gavage for 10 days. An equal number of control rats received vehicle alone. EPA treatment had no effect on blood pressure compared with control rats.3. Aortic rings from EPA‐treated rats, precontracted with PGF2α showed increased endothelium‐dependent relaxations to acetylcholine. Endothelium‐independent relaxations to sodium nitroprusside were not altered. Rings from rats fed pure EPA did not show any differences in vasoconstrictor responses to noradrenaline or serotonin.4. Serum thromboxane B2 (TXB2) levels fell 17% in animals given pure EPA, but prostacyclin production was not affected. These responses are less than those seen following Max EPA fish oil.5. Thus, pure EPA treatment did not lower blood pressure, but may have a direct effect on aortic endothelia and cause increased endothelium‐dependent relaxations in response to acetylcholine in SHR.
A TWO‐SITE MONOCLONAL IMMUNORADIOMETRIC ASSAY FOR TOTAL RENIN PROTEIN: COMPARISON WITH AN ESTABLISHED ENZYME KINETIC ASSAY
Authors: Thatcher Robin L. , Whitworth Judith A. , Casley David G. , Johnston Colin I. , Skinner Sandford L. 
Published: June 2007

SUMMARY1. A two‐site monoclonal immunoradiometric assay (IRMA) for total renin protein was established to cover the range 0.3–300 μiu. The limit of sensitivity was 2 μiu/ml plasma.2. IRMA after acid activation of plasma prorenin gave the highest and most consistent values for total plasma renin (TPRC = 197 μiu/ml, s.e.m. = 22, in 17 normal adults). In untreated plasma, TPRC measured by IRMA was lower than expected, but in amniotic fluid expected values were obtained.3. Human angiotensinogen at normal concentrations did not interfere with binding of renin to the first antibody, but ovine angiotensinogen displaced the standard curve significantly.4. TPRC measured by IRMA is convenient and highly sensitive, but either the state of activation of the enzyme or another effect of acidification of plasma influences the estimated value.5. Active renal renin may not be the appropriate reference standard for this IRMA unless plasma renin is previously activated.
ALTERING ANGIOTENSIN LEVELS BY ADMINISTRATION OF CAPTOPRIL OR INDOMETHACIN, OR BY ANGIOTENSIN INFUSION, CONTRIBUTES TO AN UNDERSTANDING OF ATRIAL NATRIURETIC PEPTIDE REGULATION IN MAN
Authors: Klemm Shelley A. , Gordon Richard D. , Tunny Terry J. , Hamlet Stephen M. 
Published: June 2007

SUMMARY1. Plasma atrial natriuretic peptide (ANP) levels were positively correlated with plasma renin activity (PRA) levels, when blood volume and blood pressure (BP) were not raised in normal subjects (NLS) or patients with postoperative aldosterone‐producing adenoma (APA), Bartter's syndrome (BS), Addison's disease, anorexia nervosa, diuretic abuse or salt‐losing congenital adrenal hyperplasia.2. Angiotensin II infusion raised ANP levels in NLS, and patients with BS, pre‐ and postoperative APA, only when BP rose, suggesting that this effect might be mediated by the rise in BP.3. Captopril lowered aldosterone and ANP levels in renal artery stenosis, but falling BP levels could mediate this effect. Captopril lowered aldosterone and BP in BS, but did not lower ANP, perhaps because angiotensin remained elevated.4. Indomethacin lowered ANP when PRA was initially normal or raised (NLS and BS), but not when PRA was suppressed (APA). This effect could not be mediated by BP, which rose, but could be mediated by renin‐angiotensin, which fell.5. Factors other than central blood volume and atrial stretch may modulate ANP levels. Plasma angiotensin II may be such a factor, and may exert an important influence at high levels, especially when blood volume is low.
THERMOGENESIS AND THE EFFECT OF INJECTED CATECHOLAMINES ON THE OXYGEN CONSUMPTION OF CAFETERIA‐FED RATS
Authors: Maxwell G. M. , Nobbs S. , Bates D. J. , Fourie F. 
Published: June 2007

SUMMARY1. The oxygen consumption (V̇o2):) of unrestrained rats given a ‘cafeteria’ (high energy, high fat) or control diet was studied. The resting values of V̇o2 were the same in each dietary group, whether maintained at 26°C or 6°C. This negative finding suggests that cafeteria feeding is not an important cause of diet‐induced thermogenesis (DIT).2. The response of each group of rats to injected noradrenaline or dopamine was also studied. Each catecholamine could increase V̇o2 values but the response was much less in cold‐adapted rats measured at 6°C. In all experimental circumstances the dopamine response exceeded that of noradrenaline. There was no evidence that the cafeteria diet consistently increased the response to either catecholamine.3. These results suggest that DIT cannot be equated with non‐shivering thermogenesis (NST). Furthermore, it is suggested that dopamine would be a better agent for measuring the oxygen equivalent of NST, since it would stimulate the dopamine receptors as well as the α‐ and β‐adrenoreceptors of brown fat.
BOOK REVIEWS
Authors: MORGAN TREFOR 
Published: June 2007

Modern Techniques of Ion Transport. Edited by B. Brenner and J.H. Stein. Churchill Livingstone, New York, 1987. $126.00. The Chance of a LCJetime: lifcriility and IVF. By Carol Dettmann and Douglas Saunders. Pages xiv + 224. Illustrated. Penguin Books, Ringwood, 1987. $14.95.
SHORT COMMUNICATION: EFFECTS OF VASOACTIVE INTESTINAL POLYPEPTIDE INFUSIONS ON RENAL FUNCTION IN PATIENTS WITH LIVER DISEASE
Authors: Calam J. , Unwin R. J. , Dorudi S. , Taylor C. , Springer C. J. , Peart W. S. 
Published: June 2007

SUMMARY1. The effect of intravenous vasoactive intestinal peptide (VIP, 6 pmol/kg per min) on renal function in six patients with cirrhosis of the liver was examined.2. VIP caused generalized vasodilation and increased plasma renin activity, but diminished the glomerular filtration rate by about one third.3. The excretion of water, sodium, potassium and calcium also fell significantly.4. These results differ from our findings in normal man in whom VIP diminished water and electrolyte secretion largely by increasing tubular reabsorption.5. It is concluded that the elevated VIP levels present in patients with severe liver disease may affect renal function, but that the presence of liver disease may affect renal responses to VIP.
EFFECT OF DIPYRIDAMOLE ON BLOOD GLUCOSE AND LIVER CYCLIC AMP LEVELS AND PLATELET COUNT DURING ENDOTOXAEMIA IN MICE
Authors: Al‐Jibouri Layla M. , Najim Rafid A. 
Published: June 2007

SUMMARY1. Blood glucose, liver cyclic AMP (cAMP) levels, and platelet count were studied at different times during a 12 h interval after intravenous (i.v.) endotoxin injection (40 mg/kg) in mice.2. Blood glucose and liver cAMP levels showed a progressive decrease in endotoxic mice and the decrease was significant after 8 and 12 h.3. Dipyridamole (50 mg/kg) administered intraperitoneally (i.p.) 7 h post‐endotoxin improved blood glucose and liver cAMP levels.4. Platelet counts were decreased after 1 h in endotoxic mice and remained decreased up to 8 h. Dipyridamole administered soon after endotoxin improved platelet counts in endotoxic mice and increased survival rate to 100%.
RENAL EFFECTS OF ATRIAL NATRIURETIC FACTOR (99–126) IN CONSCIOUS SODIUM‐REPLETE SHEEP
Authors: Yates Neale A. , McDougall John G. , Coghlan John P. , Coker Andrew R. , Gibson Angela P. , Scoggins Bruce A. 
Published: June 2007

SUMMARY1. The effect of renal arterial infusion of synthetic human atrial natriuretic factor (ANF(99–126)) on renal function in the conscious euvolaemic sheep was characterized. ANF (99–126) was infused for 2 h at 5 and 50 μg/h into the renal artery of crossbred Merino ewes with chronically indwelling cannulae inserted in the renal artery. The effect on absolute and fractional excretion of Na, K, Ca, Cl and HCO3, glomerular filtration rate (GFR), effective renal plasma flow (ERPF) and free water clearance (CH2O) were measured.2. Infusion at 50 μg/h produced a fourfold increase in Na and Cl excretion. Ca excretion increased eightfold, while K and HCO3 increased by small amounts. At the lower dose only Na, Cl and Ca excretion increased significantly. The changes in absolute excretion of each ion were closely mirrored by changes in fractional excretion. CH2O became more negative at both levels of infusion. Small changes in GFR were measured at both rates of infusion. No changes in ERPF or renin secretion were observed.3. ANF (99–126) infusion at 50 μg/h for 1 h increased the excretion of Li, such that more than 70% of the change in Na excretion was associated with the changes in Li clearance. Changes in GFR accounted for less than 10% of change in Na excretion.4. Following either long‐term (50 μg/h for 6 h) or repeated short‐term (20 μg/h for 30 min) infusions of ANF (99–126), the response of Na excretion was not sustained. The mechanisms of the tachyphylaxis remains undetermined.5. ANF (99–126) is a powerful stimulus to the absolute and fractional excretion of Na, K, Ca, Cl and HCO3. The mechanism of action is not known, but appears to be related to changes in tubular function and/or a change in glomerulotubular balance.
IONIC MECHANISMS UNDERLYING ACTION POTENTIALS IN MYOMETRIUM
Authors: Parkington H. C. , Coleman H. A. 
Published: June 2007

SUMMARY1. The ionic mechanisms underlying the simple spike action potential in longitudinal myometrium of pregnant rats and the complex action potential which occurs in the same layer of pregnant guinea‐pigs are discussed.2. The current during the upstroke of the simple spike is carried by calcium and repolarization results from inactivation of the calcium current and activation of a potassium current.3. A slow inward current underlies the plateau component of the complex action potential and calcium is involved in carrying or regulating this current.4. Single channel recordings from the longitudinal myometrium of pregnant guinea‐pigs reveal large conductance (130–170 pS) potassium channels which are activated by depolarization of the membrane. The activation of these channels during the upstroke of the spike would contribute to the rapid termination of the spike.5. The duration of the plateau component of the complex action potential closely correlates with the duration of contraction and it is suggested that sufficient calcium may enter the cell during the action potential to activate the contractile apparatus directly.
β‐ADRENOCEPTORS IN CIRCULAR AND LONGITUDINAL MYOMETRIAL MEMBRANES AND IN LUNG MEMBRANES FROM DIOESTROUS AND POST‐PARTUM GUINEA‐PIGS
Authors: Handberg Gwynneth M. , Davis Elizabeth A. , Hall Solveiga , Molenaar Peter , Summers Roger J. , Pennefather Jocelyn N. 
Published: June 2007

SUMMARY1. We have examined the binding of (—)[125I]‐cyanopindolol ((—)[125I]‐CYP) to membranes prepared from uterus and lung of dioestrous and post‐partum (1–6 days) guinea‐pigs.2. The densities of β‐adrenoceptor binding sites in circular and longitudinal myometrium from dioestrous animals were similar, and approximately one‐eighth of those in the lung. Ascorbate and ethylenediaminetetraacetic acid in the incubation medium did not affect binding.3. The numbers and affinities of β‐adrenoceptor binding sites in both myometrial layers and in lung parenchyma from post‐partum animals were similar to those in corresponding tissues from dioestrous animals.4. The distribution of β‐adrenoceptor binding sites in the post‐partum uterus was examined using receptor autoradiography. Binding to circular and longitudinal muscle layers and to the endometrium was inhibited by (—)‐propranolol (1 μmol/l), by the β2‐adrenoceptor selective antagonist ICI 118,551 (70 nmol/l), but not by the β1‐adrenoceptor selective antagonist CGP 20712A (100 nmol/l), indicating that the β‐adrenoceptor present was of the β2‐subtype.5. The ability of isoprenaline to compete for (—)[125I]‐CYP binding sites in uterine membranes from post‐partum animals was approximately twice that in corresponding preparations from dioestrous animals.6. Changes in the numbers or affinity of β2‐adrenoceptors cannot account for the marked and selective enhancement of the actions of sympathomimetic amines at β‐adrenoceptors previously observed in longitudinal myometrium taken from post‐partum guinea‐pigs. It is suggested that enhancement of later steps in the chain of events between β‐adrenoceptor occupancy and uterine relaxation, and/or a decrease in the contribution of α‐adrenoceptors to the net effect of the amine might provide alternative explanations.
EFFECTS OF ADRENALINE, ISOPRENALINE AND FORSKOLIN ON PREGNANT HUMAN MYOMETRIAL PREPARATIONS
Authors: Story Margot E. , Hall Solveiga , Ziccone Sebastian P. , Paull John D. 
Published: June 2007

SUMMARY1. The effects of adrenaline, isoprenaline and forskolin upon the evoked contractions of field‐stimulated preparations of human, pregnant, isolated myometrium have been examined. Specimens were obtained at lower segment Caesarean section from patients at 31 (n= 1) and 36–40 (n= 10) weeks of gestation.2. Adrenaline enhanced the electrically evoked contractions of all preparations studied, indicating that its predominant action on these pregnant myometrial tissues was at α‐and not β‐adrenoceptors.3. Isoprenaline in concentrations at and below 10 μmol/1 produced inhibitory effects in eight of 11 experiments. In the remaining three experiments, tissues were not responsive to the inhibitory effects of isoprenaline.4. In all preparations exposed to higher concentrations of isoprenaline (30 or 100 μmol/1), its effects were excitatory.5. Forskolin produced inhibitory effects on preparations from all uteri, including those from which tissues unresponsive to isoprenaline had been obtained.6. It is suggested that forskolin in the concentrations which were effective in this study produced its inhibitory effects largely through activation of adenylate cyclase. This implies that the lack of an inhibitory response of some preparations to isoprenaline was not due to reduced activity of the adenylate cyclase system, but that the failure of isoprenaline to produce an inhibitory effect could be due to diminished numbers of β‐adrenoceptors and/or increased numbers of α‐adrenoceptors, or to a defect in the coupling of the receptors to the adenylate cyclase system. Alternatively, the presence of an endogenous antagonist of the effects of isoprenaline (for example, an eicosanoid), could mask its inhibitory effects.7. The absence of an inhibitory effect of isoprenaline on some specimens of human gravid myometrium could have clinical implications, in view of the widespread use of β2‐adrenoceptor agonists as uterine relaxants.
EFFECTS OF RENAL DENERVATION AND ATRIAL NATRIURETIC FACTOR ON TUBULAR REABSORPTION IN ANAESTHETIZED RATS
Authors: Dowling G. J. , Harris P. J. , Skinner S. L. 
Published: June 2007

SUMMARY1. The effects of acute unilateral renal denervation were examined in 17 anaesthetized rats. Renal haemodynamic changes were monitored using standard clearance techniques. Lithium clearance was used to assess fractional proximal sodium and water reabsorption.2. Denervation resulted in ipsilateral renal vasodilatation with marked natriuresis and diuresis, a small increase (15%, P < 0.05) in glomerular filtration rate (GFR) and a consequent reduction in filtration fraction. Fractional lithium reabsorption decreased (67.3 ± 2.9% to 54.5 ± 4.0%, P < 0.01) and absolute proximal reabsorption did not change, indicating impairment of proximal glomerulotubular balance (GTB). No similar changes in haemodynamic or transport parameters were observed in the contralateral, innervated kidney, although vascular resistance increased.3. In 9 experiments following denervation of the left kidney, systemic low dose infusion (10 ng/min) of atrial natriuretic factor (ANF) resulted in a fall in mean arterial blood pressure from 116 ± 3 mmHg to 107 + 3 mmHg (P < 0.05). In the denervated kidney ANF increased urine flow rate and sodium excretion to rates above those established following denervation alone. However, in the right kidney, despite the increased filtered load (35%, P < 0.01), the natriuretic and diuretic responses to ANF were abolished.4. In the denervated kidney, ANF further reduced the fractional reabsorption of lithium from 53.6 ± 2.3% to 45.6 ± 3.8% (P < 0.05). GFR increased by 32% (a total of 49% higher than during pretreatment) but absolute proximal reabsorption (APR) did not change. However, in the right, innervated kidney ANF infusion produced a 35% increase in GFR accompanied by a 53% rise in APR.5. It is concluded that the natriuresis induced by unilateral denervation is due predominantly to impaired proximal GTB. The natriuretic action of ANF was associated with further impairment of proximal GTB, not dependent upon decreasing activity of renal sympathetic nerves, but was abolished when filtration fraction and renal sympathetic tone were elevated.
CHANGES IN HEPATIC CYTOSOLIC GLUTATHIONE S‐TRANSFERASE ENZYMES INDUCED BY CLOTRIMAZOLE TREATMENT IN RATS
Authors: González P. , Tuñón M. J. , Manrique V. , Garcia‐Pardo L. A. , González J. 
Published: June 2007

SUMMARY1. The influence of the antifungal agent clotrimazole on cytosolic glutathione S‐transferase activities was studied in male Wistar rats.2. Animals received clotrimazole by gastric lavage for 3 days (75 mg/kg per day). Hepatic glutathione S‐transferase activity was determined with five different substrates: 1‐chloro‐2,4‐dinitrobenzene (CDNB), 1,2‐dichloro‐4‐nitrobenzene (DCNB), p‐nitrobenzyl chloride (PNBC), ethacrynic acid (EA) and trans‐4‐phenyl‐3‐buten‐2‐one (TPBO).3. The largest increases in glutathione S‐transferase activity were found with CDNB, DCNB and PNBC (+ 61%, + 50% and + 50%, respectively, when expressed per mg of cytosolic protein). Enzyme activity toward EA was induced to a lower extent (+ 33%). Changes in the formation of the conjugate of TPBO were relatively small (+22%).4. These data indicate a differential induction of glutathione S‐transferase isoenzymes and suggest that clotrimazole is a phenobarbital‐type inducer of enzyme activity.
USE OF METHIONINE‐ENKEPHALIN SULFOXIDE AND LEUCINE‐ENKEPHALIN RADIO‐IMMUNOASSAYS FOR THE MEASUREMENT OF ENKEPHALINS IN THE RAT BRAIN
Authors: Tiong George K. L. , Olley Jean E. 
Published: June 2007

SUMMARY1. A radio‐immunoassay (RIA) for methionine‐enkephalin sulfoxide was developed and was used to measure methionine‐enkephalin, after oxidation, in the rat brain.2. The RIA was performed together with assays that use commercially available met‐and leu‐enkephalin antisera.3. Evidence is presented here indicating that antisera raised against the native met‐enkephalin peptide underestimate met‐enkephalin content due to loss of immunoreactivity after oxidation of peptide.4. These results show that a more accurate measurement of met‐enkephalin may be obtained by using the met‐enkephalin sulfoxide RIA. The cross‐reactivity of met‐enkephalin with the leu‐enkephalin RIA was diminished following oxidation of peptide.
μ‐ AND K‐OPIATE RECEPTOR AGONISTS REDUCE PLASMA NEUROHYPOPHYSIAL HORMONE CONCENTRATIONS IN WATER‐DEPRIVED AND NORMALLY HYDRATED RATS
Authors: Evans R. G. , Olley J. E. , Rice G. E. , Abrahams J. M. 
Published: June 2007

SUMMARY1. The effects of μ‐ and K‐opiate receptor agonists on plasma concentrations of immunoreactive (ir) oxytocin (OXY) and arginine vasopressin (AVP) in normally hydrated and water‐deprived rats were studied.2. Water‐deprivation for 36 h elevated both plasma ir‐OXY and ir‐AVP concentrations of Long‐Evans rats. These elevated levels were lowered in a dose‐dependent manner after subcutaneous administration of bremazocine (3–10 μg/kg), M320 (10–100 μg/kg) or morphine (0.1–10 mg/kg). Comparable reductions of plasma concentrations of ir‐AVP and ir‐OXY were observed.3. Plasma concentrations of ir‐OXY and ir‐AVP of normally hydrated Long‐Evans rats were lower after subcutaneous administration of bremazocine (10 μg/kg), M320 (10 μg/kg) and morphine (1.0 mg/kg).4. These data suggest that both μ‐ and K‐opiate receptor agonists inhibit both OXY and AVP release from the neurohypophysis of rats.
ENDOTHELIN IS BLOOD VESSEL SELECTIVE: STUDIES ON A VARIETY OF HUMAN AND DOG VESSELS IN VITRO AND ON REGIONAL BLOOD FLOW IN THE CONSCIOUS RABBIT
Authors: Cocks T. M. , Broughton A. , Dib M. , Sudhir K. , Angus J. A. 
Published: June 2007

SUMMARY1. Endothelin (Et), a vasoconstrictor peptide, was 5–10‐fold more potent (lower EC50) on isolated ring segments of large veins than on large arteries removed from dog coronary, mesenteric, femoral, renal and internal mammary vasculature and from the human internal mammary pedicle.2. In the dog large coronary artery, Et (10–30 nmol/L) caused transient relaxations partway through the generation of a concentration‐contraction curve. These relaxations were endothelium dependent.3. In conscious rabbits treated with mecamylamine, Et (0.025–0.4 nmol/kg) caused a marked rise in renal vascular resistance but hindquarter vasodilation. Under the same conditions angiotensin II constricted both beds.4. These studies suggest that Et is vascular bed and large vein selective in activity. It did not appear to be selective for large or small coronary arteries in vitro.