What is the organization of cerebral microvascular oxygenation and morphology that allows adequate tissue oxygenation at different activity levels? We address this question in the mouse cerebral cortex using microscopic imaging of intravascular O2 partial pressure and blood flow combined with numerical modelling. Here we show that parenchymal arterioles are responsible for 50% of the extracted ...

AMONG THE PROBLEMS presented by the chronic uraemie patient, the anaesthetist is particularly concerned with anaemia, a-3 acid-base and electrolyte upsets, and impaired renal excretion of drugs. When such patients are on chronic haemodialysis programs, they frequently present for surgical creation or revision of arteriovenous shunts and fistulae. Usually, these procedures are done under local o...

cardiovascular disease is the common cause of mortality in diabetic subjects. recently, it is indicated that peroxisome proliferator-activated receptors (ppars) agonists have beneficial effect on cardiovascular system especially on angiogenesis. ppars have three isotypes: pparα, pparβ/δ and pparγ. in this study, we evaluated the effect of bezafibrate as pan ppar agonist on myocardial capillary ...

We studied the kinetics of glucose exchange between plasma and interstitial fluid (ISF) in human skeletal muscle and adipose tissue under fasting conditions. Five normal human subjects received an intravenous [6,6-2H2]glucose infusion in a prime-continuous fashion. During the tracer infusion, the open-flow microperfusion technique was employed to frequently sample ISF from quadriceps muscle and...

The binding and buffering of O2 and CO2 in the blood influence their exchange in lung and tissues and their transport through the circulation. To investigate the binding and buffering effects, a model of blood-tissue gas exchange is used. The model accounts for hemoglobin saturation, the simultaneous binding of O2, CO2, H+, 2,3-DPG to hemoglobin, and temperature effects. Invertible Hill-type sa...

The O2-carrying blood substitute based on polymerized bovine hemoglobin (PBH) was used to determine efficacy in maintaining tissue Po2 after an 80% isovolemic blood exchange leading to a hematocrit of 19% [5.4 g Hb/dl from red blood cells (RBCs) and 6.3 g Hb/dl from PBH]. Effects were studied in terms of O2 delivery, O2 extraction, and tissue Po2 at the microcirculatory level at 1, 12, and 24 h...

AIMS Alveolar gas diffusion (DLCO) is impaired in chronic heart failure (CHF). Diffusion depends on membrane diffusion (DM) and the amount of blood participating in gas exchange (VC). How DM, VC, and the alveolar-capillary unit behave in relationship to CHF severity is unknown. METHODS AND RESULTS We measured pulmonary function, including DLCO, DM, VC, and alveolar volume (VA), in 191 CHF pat...

BACKGROUND The pharmacokinetics of extracellular solutes is determined by the blood-tissue exchange kinetics and the volume of distribution in the interstitial space in the different organs. This information can be used to develop a general physiologically based pharmacokinetic (PBPK) model applicable to most extracellular solutes. METHODS The human pharmacokinetic literature was surveyed to ...

In order to obtain further insight into the adaptive mechanisms relating to gas exchange in anatomically small lungs, tests of mechanical lung function and gas exchange were made in an active young man, whose lung growth had been severely impaired due to pectus excavatum developed in childhood. We found our patient to have small (total lung capacity, 59% of predicted) but mechanically normal lu...

N UMEROUS studies concerned with estimates of transcapillary rates of exchange of water and ions based on ‘isotopic arterial disappearance curves’ have appeared in recent years (1-9). For the most part these studies have been unsupported by examinations of the simultaneous events in tissues. It is our purpose here a) to describe water exchange and distribution rates in various tissues; b) to de...