Abstract:
:1. Oxygen (O2) transfer from the blood to tissues is a function of the red blood cell (RBC) O2 saturation (SO2), the plasma O2 content being negligible. Under conditions of increased tissue O2 demand, the SO2 of arterial blood does not change appreciably (97%); however, the SO2 of mixed venous blood, equal to that of the perfused tissues, can go as low as 20%. 2. Tissue O2 availability is limited by the exposure time to a RBC, which decreases under conditions of maximum stress (< 1 s). If the O2 unloading time was to increase significantly, because of a decrease in the RBC diffusion constant or an increase in the RBC membrane thickness, the RBC O2 unloading time would exceed tissue (e.g. cardiac) transit time and O2 transfer would be impaired. 3. Cholesterol constitutes the non-polar, hydrophobic lipid of the enveloping layer of the RBC membrane. As the cholesterol content of the RBC increases, the fluidity of the membrane decreases and the lipid shell stiffens. 4. Early studies demonstrated that high blood cholesterol concentrations were associated with reduced blood O2 transport; in essence, the haemoglobin dissociation curve was shifted to the left. 5. Current investigations have shown that the cholesterol RBC membrane barrier to O2 diffusion delayed O2 entry into the RBC during saturation and delayed O2 release from the RBC during desaturation. In an analysis of 93 patients divided by their cholesterol concentration into five groups, the percentage change in blood O2 diffusion was inversely proportional to the cholesterol concentration. 6. The RBC membrane cholesterol is in equilibrium with the plasma cholesterol concentration. It stands to reason that as the plasma cholesterol increases, the RBC membrane becomes impaired and O2 transport is reduced. 7. The implications of this new perspective on O2 transport include the ability to increase tissue oxygenation by lowering plasma cholesterol.
journal_name
Clin Exp Pharmacol Physioljournal_title
Clinical and experimental pharmacology & physiologyauthors
Buchwald H,O'Dea TJ,Menchaca HJ,Michalek VN,Rohde TDdoi
10.1046/j.1440-1681.2000.03383.xkeywords:
subject
Has Abstractpub_date
2000-12-01 00:00:00pages
951-5issue
12eissn
0305-1870issn
1440-1681journal_volume
27pub_type
杂志文章,评审abstract::1. Despite the array of sophisticated imaging techniques available for biological applications, none of the standard biomedical techniques adequately provides the capability to measure motion and flow. Those techniques currently in use are particularly lacking in spatial and temporal resolution. 2. Herein, we introduc...
journal_title:Clinical and experimental pharmacology & physiology
pub_type: 杂志文章
doi:10.1111/j.1440-1681.2008.05102.x
更新日期:2009-02-01 00:00:00
abstract::1. Contraction assays and patch clamp methods were used to determine the role of K+ channels in the regulation of contractile tone of human mesangial cells (MC) in culture. 2. MC contraction was induced by vasoconstrictor agents, such as angiotensin II (AngII; 100 nmol/L) and glybenclamide (Glyb), but not by iberiotox...
journal_title:Clinical and experimental pharmacology & physiology
pub_type: 杂志文章
doi:10.1111/j.1440-1681.1996.tb03066.x
更新日期:1996-01-01 00:00:00
abstract::1. The effects of dietary sodium on blood pressure and levels of sodium, other electrolytes and noradrenaline (NA) in the cerebrospinal fluid (CSF) and blood of 15 patients with essential hypertension were studied. The CSF and blood sampling was carried out after 7 days of a high salt intake (16-18 g/day) and after 7 ...
journal_title:Clinical and experimental pharmacology & physiology
pub_type: 杂志文章
doi:10.1111/j.1440-1681.1992.tb00444.x
更新日期:1992-04-01 00:00:00
abstract::1. Renin mRNA is present in the kidney and, in lower concentrations, in many extrarenal tissues and serves as an index of renin gene activity, as well as potential renin or prorenin synthesis in cell populations within those tissues. Unfortunately the quantity can be very low. 2. A new, highly sensitive technique is d...
journal_title:Clinical and experimental pharmacology & physiology
pub_type: 杂志文章
doi:10.1111/j.1440-1681.1991.tb01463.x
更新日期:1991-05-01 00:00:00
abstract::1. The effects of ATP and some of its more stable analogues have been examined upon preparations of epididymal and prostatic halves of vasa deferentia and of cauda epididymides from rats that had undergone vasectomy by medial transection of the vas deferens. 2. After unilateral vasectomy, the potencies of ATP, beta, g...
journal_title:Clinical and experimental pharmacology & physiology
pub_type: 杂志文章
doi:10.1111/j.1440-1681.1990.tb01358.x
更新日期:1990-08-01 00:00:00
abstract::1. Heterogeneity in the receptors for the neuropeptide calcitonin gene-related peptide (CGRP) has been apparent for nearly 20 years. This is most clearly manifested in the observation of CGRP(8-37)-sensitive and -insensitive populations of CGRP-activated receptors. The pA(2) values for CGRP(8-37) in excess of 7 are wi...
journal_title:Clinical and experimental pharmacology & physiology
pub_type: 杂志文章,评审
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更新日期:2007-10-01 00:00:00
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journal_title:Clinical and experimental pharmacology & physiology
pub_type: 杂志文章,评审
doi:10.1111/1440-1681.12688
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abstract::1. The administration of aldosterone to adrenalectomized rats produces an increase in K+ and decrease in Na+ excretion in the urine. The relationship of the post-aldosterone to the pre-aldosterone urinary sodium and potassium excretion is termed the renal response to aldosterone. 2. The administration of L-dopa enhanc...
journal_title:Clinical and experimental pharmacology & physiology
pub_type: 杂志文章
doi:10.1111/j.1440-1681.1979.tb00011.x
更新日期:1979-01-01 00:00:00
abstract::Diabetes mellitus and depressive disorders are both common chronic diseases that increase functional disability and social burden. Cognitive impairment is a potentially debilitating feature of depression. Previous evidence indicates that the antidiabetic drug metformin could be suitable for diabetic patients with cogn...
journal_title:Clinical and experimental pharmacology & physiology
pub_type: 杂志文章,随机对照试验
doi:10.1111/1440-1681.12265
更新日期:2014-09-01 00:00:00
abstract::1. Rabbits were treated with the antiparasitic drug ivermectin at subcutaneous doses of 0.2, 1 and 2.5 mg/kg and blood collected weekly for 4 weeks thereafter for measuring some blood parameters. At a dose of 0.2 or 1 mg/kg the drug had no significant effect on any of the parameters measured. At a dose of 2.5 mg/kg, t...
journal_title:Clinical and experimental pharmacology & physiology
pub_type: 杂志文章
doi:10.1111/j.1440-1681.1990.tb01273.x
更新日期:1990-10-01 00:00:00
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journal_title:Clinical and experimental pharmacology & physiology
pub_type: 杂志文章
doi:10.1111/j.1440-1681.2011.05657.x
更新日期:2012-03-01 00:00:00
abstract::Hypertension developed within 5 weeks in uninephrectomized rats administered deoxycorticosterone acetate (DOCA, 30 mg/kg, s.c., weekly) and given isotonic saline to drink. Chronic dietary administration of tryptophan (50 g/kg food) reduced intake of saline solution and prevented the elevation of systolic blood pressur...
journal_title:Clinical and experimental pharmacology & physiology
pub_type: 杂志文章
doi:10.1111/j.1440-1681.1986.tb02380.x
更新日期:1986-11-01 00:00:00
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journal_title:Clinical and experimental pharmacology & physiology
pub_type: 杂志文章
doi:10.1111/1440-1681.12773
更新日期:2017-08-01 00:00:00
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pub_type: 杂志文章,评审
doi:10.1111/j.1440-1681.2009.05213.x
更新日期:2009-12-01 00:00:00
abstract::1. Conscious experimental hypertensive rats injected intraventricularly with 5,6-dihydroxytryptamine (50 microgram) responded with a rapid and long-lasting (4 days) fall in blood pressure and this was accompanied by a bradycardia of similar duration. 2. The acute actions of 5,6-dihydroxytryptamine on the cardiovascula...
journal_title:Clinical and experimental pharmacology & physiology
pub_type: 杂志文章
doi:10.1111/j.1440-1681.1975.tb01855.x
更新日期:1975-11-01 00:00:00
abstract::1. A comparison has been made of the effects of three acetylcholine antagonists--hexamethonium, tubocurarine and pancuronium--on maximal tetani of limb muscles of cats under chloralose anaesthesia. In most experiments, the indirectly stimulated soleus muscle was studied, but observations were also made on the tibialis...
journal_title:Clinical and experimental pharmacology & physiology
pub_type: 杂志文章
doi:10.1111/j.1440-1681.1976.tb00636.x
更新日期:1976-11-01 00:00:00
abstract::The distribution and binding characteristics of the radioligand (-)-[125I]-cyanopindolol (CYP) have been examined in slide mounted mouse kidney sections, using the technique of in vitro labelling and autoradiography. (-)-[125I]-CYP binding to sections was of high affinity (KD = 55.8 pmol/l, s.e.m. = 8.1, n = 4) to a s...
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pub_type: 杂志文章
doi:10.1111/j.1440-1681.1986.tb00339.x
更新日期:1986-03-01 00:00:00
abstract::1. Pressor responsiveness to angiotensin II (AII) and phenylephrine (PHE) was measured before and after 5 days of ACTH (1 mg i.m. daily) in six normal men maintained on low sodium diet (15 mmol daily). 2. ACTH caused a significant increase in systolic blood pressure of 9 mmHg. 3. There was no change in pressor respons...
journal_title:Clinical and experimental pharmacology & physiology
pub_type: 杂志文章
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更新日期:1987-03-01 00:00:00
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journal_title:Clinical and experimental pharmacology & physiology
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doi:10.1111/j.1440-1681.1991.tb01440.x
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journal_title:Clinical and experimental pharmacology & physiology
pub_type: 杂志文章
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更新日期:2009-08-01 00:00:00
abstract::1. Positive inotropic effect of taurine and improvement of cardiac performance of failing heart are mediated through the modulation of Ca2+ movement through the sarcolemma. 2. Cardioprotection with glutamate and aspartate is related to enhanced anaerobic energy formation in mitochondria coupled with succinate formatio...
journal_title:Clinical and experimental pharmacology & physiology
pub_type: 杂志文章,评审
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更新日期:1996-08-01 00:00:00
abstract::1. Adrenaline can enhance the stimulation-induced release of transmitter noradrenaline in sympathetically innervated tissues by activating prejunctional beta-adrenoceptors. 2. Adrenaline incorporated into sympathetic transmitter stores by neuronal uptake can be subsequently released as a co-transmitter and can then ac...
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pub_type: 杂志文章
doi:10.1111/j.1440-1681.1981.tb00750.x
更新日期:1981-09-01 00:00:00
abstract::1. A method is described which allows the determination of liquid junction potentials between biological fluid samples of less than 1 nL with a reproducibility of 10%. This was achieved by use of a micro-method and the use of 3% agarose added to the electrolyte in the measuring electrodes. 2. Validation was performed ...
journal_title:Clinical and experimental pharmacology & physiology
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doi:10.1111/j.1440-1681.1989.tb01605.x
更新日期:1989-07-01 00:00:00
abstract::Autophagy promotes cell survival or induces apoptosis in cancer cells. While SIRT1 and AMPK induce autophagy in both normal and cancer cells, Akt and mTOR can inhibit it. Calycosin, a methoxyisoflavone, protects against several types of solid tumours including colorectal cancer. However, the mechanisms behind the anti...
journal_title:Clinical and experimental pharmacology & physiology
pub_type: 杂志文章
doi:10.1111/1440-1681.13133
更新日期:2019-10-01 00:00:00
abstract::This study explored the effects and mechanisms of dopamine D1 receptors (DR1) activation on the apoptosis of osteosarcoma cells (OS732).The DR1 agonist SKF-38393 decreased the viability of OS732 cells and increased their rate of apoptosis, whereas the DR1 antagonist SCH-23390 abolished the effects of SKF-38393. In OS7...
journal_title:Clinical and experimental pharmacology & physiology
pub_type: 信件
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更新日期:2017-11-01 00:00:00
abstract::1. Endothelium-derived nitric oxide (NO), a major modulator of vascular tone, is synthesized from the terminal guanidino nitrogen of L-arginine. This reaction is inhibited by analogues of L-arginine, such as N-nitro-L-arginine methyl ester (L-NAME). Many of the biological effects of NO are mediated by the second messe...
journal_title:Clinical and experimental pharmacology & physiology
pub_type: 杂志文章
doi:
更新日期:1996-01-01 00:00:00
abstract::1. We have studied the role of kallikrein (KK) in the maintenance of renal function in chronic hypoxic rats (high altitude; HA), compared with control rats kept at sea level (SL). Hypoxia was induced by placing female Wistar rats (198-290 g) in an altitude chamber (5500 m) 15 h/day for 4 weeks. Experiments were also c...
journal_title:Clinical and experimental pharmacology & physiology
pub_type: 杂志文章
doi:10.1111/j.1440-1681.1996.tb01186.x
更新日期:1996-09-01 00:00:00
abstract::1. Recent data from randomized controlled dietary trials have shown blood pressure-lowering effects of foodstuffs and dietary patterns to be of practical importance for both individual and population blood pressure control. 2. The salient studies include Dietary Approaches to Stop Hypertension (DASH) trials, on comple...
journal_title:Clinical and experimental pharmacology & physiology
pub_type: 杂志文章
doi:10.1046/j.1440-1681.2001.03562.x
更新日期:2001-12-01 00:00:00
abstract::1. Serial observations of blood pressure after unilateral adrenalectomy for aldosterone-producing adenoma revealed an incidence of hypotension (systolic BP less than fifth percentile for age- and sex-matched normal population) of 27% at 2 years, more than 5 times that predicted. 2. Serial observations of volume regula...
journal_title:Clinical and experimental pharmacology & physiology
pub_type: 杂志文章
doi:10.1111/j.1440-1681.1989.tb01558.x
更新日期:1989-04-01 00:00:00
abstract::Chemotherapy resistance is a major contributor to poor treatment responses and tumour relapse, the development of which has been strongly linked to the action of cancer stem cells (CSCs). Mounting evidence suggests that CSCs are reliant on low oxygen conditions and hypoxia-inducible factors 1α and 2α (HIF1α and HIF2α)...
journal_title:Clinical and experimental pharmacology & physiology
pub_type: 杂志文章,评审
doi:10.1111/1440-1681.12693
更新日期:2017-02-01 00:00:00