{'fraction_non_alphanumeric': 0.04050833995234313, 'fraction_numerical': 0.03335980937251787, 'mean_word_length': 4.779816513761468, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Determining the dose‐dependent effects of long‐chain soluble polymers in rat spinotrapezius muscle

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 PO2, 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.