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Determining the dose‐dependent effects of long‐chain soluble polymers in rat spinotrapezius muscle
Author(s) -
Connery Michael,
Kameneva Marina V,
Pittman Roland N
Publication year - 2010
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.24.1_supplement.lb555
Subject(s) - saline , polyethylene oxide , hemodynamics , chemistry , blood flow , blood pressure , polymer , anesthesia , medicine , organic chemistry
Long‐chain soluble polymers (LSPs) have been shown to have profound hemodynamic effects at very low concentrations. At only 5 ppm in blood, LSPs increase blood flow and reduce vascular resistance. Despite studies showing therapeutic value in cases of hemorrhage, myocardial infarction, and atherosclerosis, the mechanism of action is unknown. The purpose of this study was to determine the dose‐dependency of LSPs on systemic and microcirculatory variables. Sprague‐Dawley rats were anesthetized and their spinotrapezius muscles isolated for transillumination. The experimental group (n=2) was given serial injections of the LSP polyethylene oxide (mol wt 4500 kDa) dissolved in saline to reach blood concentrations of 0.12, 0.4, 1.2 and 4 ppm. The control group (n=8) was given serial injections of the same volumes of saline. At 4 ppm, mean arterial pressure was lower in the LSP group (90 ± 2 mmHg vs 108 ± 17 mmHg). Interstitial PO 2 , as measured by phosphorescence quenching, was higher in the LSP group at 0.12 ppm (67 ± 3 mmHg vs 60 ± 4 mmHg) and 0.4 ppm (66 ± 2 mmHg vs 60 ± 4 mmHg). These findings are consistent with previous reports of this polymer. Support: NHLBI HL18292 and HL079087