Pulmonary vascular protein sieving capability after exposure to high vascular pressures.
Animals; Barotrauma/physiopathology; Blood Pressure/physiology; Blood Proteins/chemistry/*metabolism; Chemical; Dogs; Electrophoresis; Hypertension; Lymph/cytology/metabolism; Male; Models; Muscle; Permeability; Polyacrylamide Gel; Pulmonary Circulation/*physiology; Pulmonary Edema/physiopathology; Pulmonary/*physiopathology; Smooth; Vascular/*physiology
We evaluated the ability of the canine in situ left lower lobe (LLL) vasculature to sieve endogenous plasma proteins of various molecular radii (34-124 A) after LLL arterial pressure had been transiently elevated to 23.8 +/- 0.9 (control group, n = 5) or 92.3 +/- 1.4 (SE) Torr (high-pressure group, n = 9) by restricting LLL venous outflow under conditions of constant flow. After LLL flow was returned to natural perfusion, left atrial pressure was elevated in step increments, and LLL lymph and blood samples were collected until filtration-independent lymph-to-plasma protein concentration ratios (CL/CP) were obtained. The osmotic reflection coefficients (sigma d) for total proteins and seven protein fractions (separated by gradient gel electrophoresis) were calculated. The average total protein sigma d of the high-pressure group [0.51 +/- 0.06 (SE)] was significantly lower than that of the control group (0.68 +/- 0.03). Several LLLs of the high-pressure group, however, exhibited normal sigma d's. Protein fraction CL/CP's decreased with increasing molecular radius in both groups, but the CL/CP-molecular radius relationship was displaced upward in the high-pressure group. Pore analysis suggested that the decreases in sigma d could be explained by increases in the fractional flow through a large-pore system.
Bosso F J; Maron M B; Pilati C F; Jarjoura D G
Journal of applied physiology (Bethesda, Md. : 1985)
1992
1992-07
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1152/jappl.1992.73.1.50" target="_blank" rel="noreferrer noopener">10.1152/jappl.1992.73.1.50</a>
Role of endothelium in sexual dimorphism in vasopressin-induced contraction of rat aorta.
*Sex Characteristics; *Vasoconstriction; Animals; Aorta/*drug effects; Arginine Vasopressin/*pharmacology; Arginine/analogs & derivatives/pharmacology; Endothelium; Female; Indomethacin/pharmacology; Male; Nitric Oxide/antagonists & inhibitors; omega-N-Methylarginine; Osmolar Concentration; Phenylephrine/pharmacology; Rats; Sprague-Dawley; Vascular/*physiology
In rat thoracic aorta, contractile responses to arginine vasopressin (AVP) are twofold higher in females than in males. To determine the role of the endothelium in this phenomenon, the effects of endothelium removal and inhibition of nitric oxide (NO) synthase and cyclooxygenase were examined in thoracic aortas prepared from male and female Sprague-Dawley rats and mounted for isometric tension recording. Maximal contractile response to AVP was substantially higher in female (4,232 +/- 316 mg/mg ring dry wt) than in male aortas (1,365 +/- 239; P \textless 0.01). Removal of the endothelium markedly potentiated maximal response to AVP in male aortas (4,100 +/- 422 mg/mg ring wt; P \textless 0.01); endothelium removal increased sensitivity but not maximal response in female aortas. Inhibition of NO synthase with NG-monomethyl-L-arginine (L-NMMA, 250 microM) doubled maximal contraction to AVP in male aortas (3,175 +/- 193 mg/mg ring wt; P \textless 0.01); L-NMMA increased sensitivity but not maximal response in female aortas. Inhibition of cyclooxygenase with indomethacin (10 microM) did not alter maximal response to AVP in male aortas but significantly attenuated responses of female aortas (2,816 +/- 306 mg/mg ring wt; P \textless 0.01). In contrast, maximal contractile response to phenylephrine hydrochloride (PE) was 40% higher in males than in females (P \textless 0.01); L-NMMA increased both the sensitivity and maximal response to PE to a greater extent in female (3,061 +/- 121 vs. 4,971 +/- 135 mg/mg ring wt; P \textless 0.01) than in male aortas (4,317 +/- 227 vs. 4,899 +/- 104 mg/mg ring wt; P \textless 0.01). (ABSTRACT TRUNCATED AT 250 WORDS)
Stallone J N
The American journal of physiology
1993
1993-12
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1152/ajpheart.1993.265.6.H2073" target="_blank" rel="noreferrer noopener">10.1152/ajpheart.1993.265.6.H2073</a>