Heterogeneity of Vascular Innervation in Hamster Cheek Pouch and Retractor Muscle

1999 ◽  
Vol 36 (6) ◽  
pp. 465-476 ◽  
Author(s):  
Dallas J. Grasby ◽  
Judy L. Morris ◽  
Steven S. Segal
Keyword(s):  
Cheek Pouch ◽  
Retractor Muscle ◽  
Hamster Cheek Pouch ◽  
Vascular Innervation

Measurement of hemoglobin oxygen saturation in capillaries

1987 ◽  
Vol 252 (5) ◽  
pp. H1031-H1040 ◽  
Author(s):  
M. L. Ellsworth ◽  
R. N. Pittman ◽  
C. G. Ellis
Keyword(s):  
Light Intensity ◽  
Oxygen Saturation ◽  
Red Blood Cells ◽  
Optical Density ◽  
Blood Cells ◽  
Striated Muscle ◽  
Cheek Pouch ◽  
Retractor Muscle ◽  
Hamster Cheek Pouch

We present a computer-aided videodensitometric method for the determination of oxygen saturation in red blood cells flowing through capillaries of the hamster cheek pouch retractor muscle. The optical density (OD) of red blood cells is determined at two wavelengths. At the first, 431 nm, there is a maximum difference between absorption by oxygen deoxyhemoglobin. At the second, 420 nm, absorption is equal for the two absorbing species (isosbestic wavelength). In capillaries of the retractor muscle a relationship between oxygen saturation (S) and the following OD ratio was obtained as S = -1.71 (OD431/OD420) + 2.20. The error (95% confidence interval) in oxygen saturation associated with a determination of the OD ratio is estimated to be +/- 4.8%. The computerization of the method employs a frame-by-frame analysis of the light intensity over a selected capillary segment. The light intensity waveform along the segment is digitized and the minimum (I) and maximum (I0) light intensities are used to compute an optical density (OD = log10 [I0/I]). These minimum and maximum intensities correspond to the presence and absence of a red blood cell, respectively. The method permits the off-line analysis of videotaped scenes and provides a means of assessing the extent of temporal and spatial heterogeneity of oxygen saturation in selected capillary networks. The method has been developed for use in capillaries in transilluminated striated muscle but should be generally applicable to the measurement of capillary oxygen saturation in other tissues.

Rate of oxygen loss from arterioles is an order of magnitude higher than expected

1989 ◽  
Vol 256 (3) ◽  
pp. H921-H924 ◽  
Author(s):  
A. S. Popel ◽  
R. N. Pittman ◽  
M. L. Ellsworth
Keyword(s):  
Experimental Data ◽  
Oxygen Flux ◽  
Cheek Pouch ◽  
Retractor Muscle ◽  
Hamster Cheek Pouch ◽  
Oxygen Loss ◽  
Order Of Magnitude ◽  
Solubility Coefficients ◽  
Tissue Permeability

The experimental data on oxygen flux from arterioles in the hamster cheek pouch retractor muscle [L. Kuo and R. N. Pittman, Am. J. Physiol. 254 (Heart Circ. Physiol. 23): H331-H339, 1988] were analyzed under the assumption that the permeability to oxygen is the same in both perfused and unperfused tissue; permeability is defined as the product of the diffusion and solubility coefficients. However, our analysis indicated that the observed oxygen flux was inconsistent with this assumption and that permeability to oxygen of a blood-perfused tissue may be an order of magnitude higher than previously assumed.

Arterioles supply oxygen to capillaries by diffusion as well as by convection

1990 ◽  
Vol 258 (4) ◽  
pp. H1240-H1243 ◽  
Author(s):  
M. L. Ellsworth ◽  
R. N. Pittman
Keyword(s):  
Oxygen Saturation ◽  
Red Blood Cells ◽  
Oxygen Transport ◽  
Blood Cells ◽  
Oxygen Exchange ◽  
Cheek Pouch ◽  
Retractor Muscle ◽  
Hamster Cheek Pouch ◽  
Local Oxygen

In the early part of this century, August Krogh proposed a model of oxygen transport in capillaries that assumes that all oxygen is delivered to the capillaries by convection from small terminal arterioles and lost from these capillaries by diffusion. This model and its consequences have been used extensively to interpret whole organ oxygen transport data in terms of diffusion between capillaries and tissues and to relate changes in microvascular hemodynamics to alterations in oxygen transport. We evaluated the appropriateness of such extrapolation by measuring oxygen saturation at discrete locations along the lengths of individual capillaries in the hamster cheek pouch retractor muscle. Our results indicate that the amount of oxygen lost from individual capillaries can be markedly affected by the presence of larger microvessels that frequently cross the capillary path. These larger vessels act either as a diffusive supply of oxygen for the red blood cells within the capillary or as an additional sink for the oxygen depending on the direction of the oxygen tension gradient. This transfer of oxygen between larger microvessels and capillaries attenuates the importance of capillary hemodynamics in oxygen exchange. Therefore, conclusions about local oxygen exchange that utilize only hemodynamic data from whole organ or microvascular experiments and the Krogh model will generally be invalid and should be viewed with caution.

Simulation of O2 transport in skeletal muscle: diffusive exchange between arterioles and capillaries

1994 ◽  
Vol 267 (3) ◽  
pp. H1214-H1221 ◽  
Author(s):  
T. W. Secomb ◽  
R. Hsu
Keyword(s):  
Skeletal Muscle ◽  
Oxygen Transport ◽  
Metabolic Regulation ◽  
Three Dimensional ◽  
Cheek Pouch ◽  
Retractor Muscle ◽  
Hamster Cheek Pouch ◽  
Consumption Rates ◽  
Three Dimensional Configuration ◽  
Diffusive Exchange

Theoretical simulations of oxygen transport in skeletal muscle are used to study the role of arterioles in oxygen delivery. A three-dimensional configuration of capillaries and arterioles in a cuboidal tissue region is simulated, based on observations of hamster cheek pouch retractor muscle. Equations describing convective and diffusive oxygen transport are solved using a Green's function method. In resting muscle, predicted oxygen saturation of capillary blood increases as it flows toward arterioles, and adjacent capillaries flowing in opposite directions show very similar variations in saturation. Diffusive oxygen loss from arterioles equals about 85% of consumption. Capillaries absorb much of this oxygen (equal to approximately 45% of consumption) and deliver it at downstream locations. Thus diffusive exchange between arterioles and capillaries plays an important part in distributing oxygen throughout the tissue. At higher flow and consumption rates, the relative amounts of oxygen diffusing out of arterioles and into capillaries decrease. The results are consistent with the hypothesis that oxygen content of arteriolar blood participates in metabolic regulation of blood flow.

A new preparation for microcirculatory studies of the hamster cheek pouch

1985 ◽  
Vol 248 (1) ◽  
pp. H143-H146
Author(s):  
M. J. Davis ◽  
R. W. Gore
Keyword(s):  
Optical Resolution ◽  
Vascular Supply ◽  
Cheek Pouch ◽  
Retractor Muscle ◽  
Surgical Trauma ◽  
Hamster Cheek Pouch ◽  
Thin Glass ◽  
Support Plate ◽  
Made In ◽  
Glass Support

Existing methods of preparing the hamster cheek pouch for observation under an intravital microscope have several disadvantages. The everted method, described by Duling (Microvasc. Res. 5: 423-429, 1973), appears to restrict blood flow by placing unnatural tension on the retractor muscle and by requiring an incision in the tip of the pouch. The method of Yamaki et al. (Microvasc. Res. 21: 299-301, 1981) requires an incision in the tip of the pouch and complete disconnection of the retractor muscle. The chamber method of Greenblatt et al. (Microvasc. Res. 1: 420-432, 1969) has a limited optical resolution because the tissue cannot easily be transilluminated with properly condensed light. We have devised a less traumatic method of preparing the pouch, which eliminates these disadvantages. The hamster is anesthetized, and a thin, glass support plate is inserted into the left cheek pouch. The plate is constructed and positioned so that it does not restrict flow to any part of the pouch. The free end of the plate is secured to the animal stage. An incision is made in the skin to expose the cheek pouch, and the loose, avascular connective tissue investing the pouch and the retractor muscle is removed. The pouch is positioned at an angle of 20 degrees from the hamster's body in a temperature-controlled chamber over a standard microscope condensor system. Throughout both surgical and experimental procedures, the pouch is superfused with Ringer-bicarbonate solution at 37.5 degrees C. This preparation minimizes surgical trauma and allows the entire vascular supply to the cheek pouch to be studied.

scholarly journals Perchloric acid-soluble proteins from goat liver inhibit chemical carcinogenesis of Syrian hamster cheek-pouch carcinoma

1998 ◽  
Vol 79 (1) ◽  
pp. 54-58 ◽  
Author(s):  
F Ghezzo ◽  
G N Berta ◽  
B Bussolati ◽  
A Bosio ◽  
G Corvetti ◽  
...  
Keyword(s):  
Perchloric Acid ◽  
Syrian Hamster ◽  
Chemical Carcinogenesis ◽  
Soluble Proteins ◽  
Cheek Pouch ◽  
Hamster Cheek Pouch
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