scholarly journals Augmented tissue oxygen supply during striated muscle contraction in the hamster. Relative contributions of capillary recruitment, functional dilation, and reduced tissue PO2.

1982 ◽  
Vol 51 (6) ◽  
pp. 711-721 ◽  
Author(s):  
B Klitzman ◽  
D N Damon ◽  
R J Gorczynski ◽  
B R Duling
Keyword(s):  
Muscle Contraction ◽  
Oxygen Supply ◽  
Striated Muscle ◽  
Tissue Oxygen ◽  
Capillary Recruitment ◽  
Tissue Po2 ◽  
Tissue Oxygen Supply

Microvascular adaptations during maturation of striated muscle

1981 ◽  
Vol 241 (3) ◽  
pp. H317-H324 ◽  
Author(s):  
I. H. Sarelius ◽  
D. N. Damon ◽  
B. R. Duling
Keyword(s):  
Oxygen Supply ◽  
Striated Muscle ◽  
Important Determinant ◽  
Capillary Density ◽  
Cremaster Muscle ◽  
Tissue Oxygen ◽  
Functional Reserve ◽  
Parallel Pattern ◽  
Muscle Changes ◽  
Tissue Oxygen Supply

It is well known that capillary density in striated muscle changes during maturation. Capillary density is an important determinant of tissue oxygen supply, the other principal determinants being capillary erythrocyte flow and capillary hematocrit. The microcirculation of the hamster cremaster muscle was studied at different stages of development. We found that the microcirculation of juvenile animals was characterized by small intercapillary distances, short capillary lengths, and tortuous vessels. During maturation, the capillaries elongated and developed the more “typical” parallel pattern. Capillary density decreased from 1,626 +/- 60 capillaries . mm-3 at 35 days of age to 696 +/- 65 capillaries . mm-3 at 132 days; erythrocyte flow per capillary decreased from 1,441 +/- 135 to 583 +/- 47 micrometers 3 . s-1; and capillary hematocrit decreased from 21.5 +/- 0.7 to 14.6 +/- 0.6%. Concomitant with these decreases, the functional reserve increased; in adult muscles, capillary density could increase by 42%, erythrocyte flow per capillary by 457.2%, and capillary hematocrit by 112.4%, compared with 7.7, 20.3, and 24.1%, respectively, in immature animals. These observations show that age significantly modifies microvascular parameters related to tissue oxygen supply and provides an explanation for some conflicting observations in the literature.

MODELLING HYDROGEN CLEARANCE FROM THE RETINA

2018 ◽  
Vol 59 (3) ◽  
pp. 281-292
Author(s):  
D. E. FARROW ◽  
G. C. HOCKING ◽  
S. J. CRINGLE ◽  
D.-Y. YU
Keyword(s):  
Blood Flow ◽  
Oxygen Supply ◽  
Retinal Blood Flow ◽  
Experimental Measurements ◽  
Human Retina ◽  
Light Path ◽  
Tissue Oxygen ◽  
Sophisticated Model ◽  
Tissue Oxygen Supply ◽  
Hydrogen Clearance

The human retina is supplied by two vascular systems: the highly vascular choroidal, situated behind the retina; and the retinal, which is dependent on the restriction that the light path must be minimally disrupted. Between these two circulations, the avascular retinal layers depend on diffusion of metabolites through the tissue. Oxygen supply to these layers may be threatened by diseases affecting microvasculature, for example diabetes and hypertension, which may ultimately cause loss of sight.An accurate model of retinal blood flow will therefore facilitate the study of retinal oxygen supply and, hence, the complications caused by systemic vascular disease. Here, two simple models of the blood flow and exchange of hydrogen with the retina are presented and compared qualitatively with data obtained from experimental measurements. The models capture some interesting features of the exchange and highlight effects that will need to be considered in a more sophisticated model and in the interpretation of experimental results.

Myocardial tissue oxygen supply and utilization during coronary artery bypass surgery: evidence of microvascular no-reflow

2000 ◽  
Vol 98 (3) ◽  
pp. 321 ◽  
Author(s):  
Mohamed K. AL-OBAIDI ◽  
Philip J. ETHERINGTON ◽  
David J. BARRON ◽  
C. Peter WINLOVE ◽  
John R. PEPPER
Keyword(s):  
Coronary Artery ◽  
Coronary Artery Bypass ◽  
Coronary Artery Bypass Surgery ◽  
Oxygen Supply ◽  
Bypass Surgery ◽  
Artery Bypass ◽  
Myocardial Tissue ◽  
Tissue Oxygen ◽  
No Reflow ◽  
Tissue Oxygen Supply

scholarly journals Possible contribution of erythrocytes to the purinergic regulation of tissue oxygen delivery

2019 ◽  
Vol 73 ◽  
pp. 141-151
Author(s):  
Jacek Sikora
Keyword(s):  
Oxygen Supply ◽  
Vascular Endothelial Cells ◽  
Cell Communication ◽  
Atp Release ◽  
Cell Types ◽  
Tissue Oxygen ◽  
Oxygen Utilization ◽  
Gi Protein ◽  
Tissue Oxygen Supply

ATP release occurs in virtually all cell types and tissues. It is considered to be a key component of a ubiquitous, evolutionary ancient cell-to-cell communication system. The regulated release of ATP is also believed to be a part of a mechanism which facilitates matching tissue oxygen supply with demand. In this paper, ATP signaling is reviewed, regulation of tissue oxygen supply is outlined, and a concept attributing a role in this process to erythrocytes releasing ATP is discussed. Oxygen saturation of hemoglobin in erythrocytes traveling through a tissue reflects the level of oxygen utilization of that tissue. Therefore, erythrocytes can serve as local oxygen sensors. In the proposed mechanism, upon hemoglobin deoxygenation, Gi protein in the erythrocyte plasma membrane is activated. The activation of Gi protein initiates a cAMP-dependent pathway, leading to ATP efflux through pannexin channels. Extracellular ATP triggers vasodilatation via P2Y receptors on the surface of vascular endothelial cells, increasing blood flow in tissue regions of elevated oxygen consumption. Despite the abundance of compelling evidence in support of this concept, some details remain elusive, in particular, the process of Gi protein activation in response to hemoglobin desaturation. Furthermore, the involvement of cAMP, as well as the final conduit of ATP release from erythrocytes, remains controversial. Finally, the actual physiological relevance of the proposed regulatory mechanism will require further in vivo research.

Dopexamine Reverses the Vasopressin-Associated Impairment in Tissue Oxygen Supply but Decreases Systemic Blood Pressure in Ovine Endotoxemia

2004 ◽  
Vol 99 (3) ◽  
pp. 878-885 ◽  
Author(s):  
Martin Westphal ◽  
Andreas Wilhelm Sielenkämper ◽  
Hugo Van Aken ◽  
Henning Dirk Stubbe ◽  
Fritz Daudel ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Oxygen Supply ◽  
Systemic Blood Pressure ◽  
Tissue Oxygen ◽  
Systemic Blood ◽  
Tissue Oxygen Supply

Experimental manipulations of tissue oxygen supply do not affect warming tolerance of European perch

2015 ◽  
Vol 218 (15) ◽  
pp. 2448-2454 ◽  
Author(s):  
J. Brijs ◽  
F. Jutfelt ◽  
T. D. Clark ◽  
A. Grans ◽  
A. Ekstrom ◽  
...  
Keyword(s):  
Oxygen Supply ◽  
Tissue Oxygen ◽  
European Perch ◽  
Tissue Oxygen Supply
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