scholarly journals Capillary pressure during and after incremental venous pressure elevation in man.

1995 ◽  
Vol 485 (1) ◽  
pp. 213-219 ◽  
Author(s):  
I R Mahy ◽  
J E Tooke ◽  
A C Shore
Keyword(s):  
Capillary Pressure ◽  
Venous Pressure ◽  
Pressure Elevation

Capillary pressures in rat intestinal muscle and mucosal villi during venous pressure elevation

1985 ◽  
Vol 249 (1) ◽  
pp. H174-H187 ◽  
Author(s):  
M. J. Davis ◽  
R. W. Gore
Keyword(s):  
Blood Flow ◽  
Capillary Pressure ◽  
Venous Pressure ◽  
Myogenic Response ◽  
Fluid Exchange ◽  
Pressure Elevation ◽  
Direct Measurements ◽  
Capillary Pressures ◽  
The Relationship ◽  
Blood Flow Redistribution

Whole-organ experiments designed to estimate the capillary filtration coefficient require information about the numerical relationship between capillary pressure and venous pressure. Indirect estimates using isogravimetric and isovolumetric methods indicate that 62-85% of a step change in venous pressure reaches the intestinal capillaries, taken as a whole. We have made direct measurements of capillary pressure with a servo-null micropressure system in the microcirculation of both the intestinal muscle and the mucosal villi of rats during local elevation of venous pressure. Consistent regional differences in the relationship between capillary pressure and venous pressure were observed. During increased venous pressure, submucosal arterioles constricted, while muscularis arterioles dilated. The diameter changes of the small arterioles were consistent with blood flow redistribution from mucosa to muscle during venous pressure elevation, but inconsistent with a pure myogenic response. These data raise questions about the exact role for the expression of the myogenic response during venous pressure elevation in the intestine and about previous interpretations of whole-organ experiments concerned with intestinal blood flow and fluid exchange.

VENOUS PRESSURE ELEVATION AND CEREBRAL AUTOREGULATION

1983 ◽  
Vol 11 (3) ◽  
pp. 254 ◽  
Author(s):  
Elizabeth M. Wagner ◽  
Richard J. Traystman
Keyword(s):  
Cerebral Autoregulation ◽  
Venous Pressure ◽  
Pressure Elevation

Secondary Glaucoma to Venous Pressure Elevation. Radius-Maumenee Syndrome

2021 ◽  
Vol 49 (4ENG) ◽  
pp. 11-21
Author(s):  
Rodolfo A. Pérez Grossmann ◽  
Rodolfo A. Pérez Simons ◽  
Luis A. Villa Cabrera
Keyword(s):  
Venous Pressure ◽  
Secondary Glaucoma ◽  
Pressure Elevation

Microvascular control of capillary pressure during increases in local arterial and venous pressure

1988 ◽  
Vol 254 (4) ◽  
pp. H772-H784 ◽  
Author(s):  
M. J. Davis
Keyword(s):  
Hydrostatic Pressure ◽  
Capillary Pressure ◽  
Venous Pressure ◽  
The Body ◽  
Cell Velocity ◽  
Arterial Inflow ◽  
Tissue Act ◽  
Pallid Bats ◽  
Red Cell Velocity ◽  
Capillary Pressures

The extent to which capillary hydrostatic pressure might be protected from increases in local arterial and venous pressure was examined in the wing microcirculation of unanesthetized pallid bats (Antrozous pallidus). Arterial inflow and venous outflow pressures to the wing were elevated using a box technique to increase pressure around the body of the animal in steps of 12 mmHg between 0 and +60 mmHg for 3-min periods. During this time, hydrostatic pressure, diameter, and red cell velocity in single microvessels were continuously recorded. All branching orders of arterioles constricted significantly during increases in box pressure (Pb), while capillaries and venules dilated. First-order arteriole and venule pressures increased 1:1 with Pb. Capillary pressures increased by only a fraction of Pb up to +36 mmHg, but at higher Pb, the change in capillary pressure was equivalent to the change in Pb. Calculations of vascular resistance indicate that changes in both pre- and postcapillary resistance in this tissue act to prevent increases in capillary pressure during moderate, but not during large, increases in arterial and venous pressure.

Intestinal capillary filtration in acute and chronic portal hypertension

1988 ◽  
Vol 254 (3) ◽  
pp. G339-G345 ◽  
Author(s):  
R. J. Korthuis ◽  
D. A. Kinden ◽  
G. E. Brimer ◽  
K. A. Slattery ◽  
P. Stogsdill ◽  
...  
Keyword(s):  
Blood Flow ◽  
Portal Hypertension ◽  
Capillary Pressure ◽  
Vascular Resistance ◽  
Interstitial Fluid ◽  
Venous Pressure ◽  
Fluid Pressure ◽  
Lymph Flow ◽  
Interstitial Fluid Pressure ◽  
Capillary Filtration

The impact of acute and chronic portal hypertension on the dynamics of intestinal microvascular fluid exchange was examined in anesthetized, fasted, sham-operated control rats with normal portal pressures (CON), during acute elevations in portal pressure (APH) in control rats, and in rats in which chronic portal hypertension (CPH) was produced by calibrated stenosis of the portal vein 10 days prior to the experiments. Although intestinal blood flow and vascular resistance were not altered by APH in control rats, CPH was associated with an increased intestinal blood flow and reduced intestinal vascular resistance when compared with CON and APH. Intestinal capillary pressure and lymph flow were elevated in APH and CPH relative to control values. However, the increase in both variables was greater in CPH. The capillary filtration coefficient was elevated only in CPH. The transcapillary oncotic pressure gradient was not altered by APH or CPH. Interstitial fluid pressure was increased from -1.1 mmHg in CON to 3.9 mmHg during APH and to 5.0 mmHg in CPH. The results of this study indicate that chronic elevations in portal venous pressure produce larger increments in intestinal capillary pressure and filtration rate than do acute elevations in portal venous pressure of the same magnitude. However, the potential edemagenic effects of elevated capillary pressure in both acute and chronic portal hypertension are opposed by increases in lymph flow and interstitial fluid pressure.

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