| Summary: | 碩士 === 國防醫學院 === 生理學研究所 === 90 === The purpose of this work was to evaluate the process of lipopolysaccharide (LPS)-induced sepsis shock by peripheral and central administration in conscious WKY rats. Changes in mean blood pressure、heart rate、blood NOx products and baroreflex activities were evaluated. In conscious WKY Rats, a single intravenous dose of lipopolysaccharide (LPS 10mg/kg) temporally decreased the mean blood pressure in 15 mins (from 128.757.72 to 78.139.59 mmHg, p0.05, n=8) that recorvered in 2h, and caused a reflex tachycardia; Heart rate constantly and siginificantly increased in 24h that reached maximal in 6h (from 362.521.11 to 47011.95 bpm, p0.05, n=8); NOx increased in 4h and reached maximal in 7h (from 15.875.03 to 357.388.11 M, p0.05, n=8) that recorverd in 24h；Body temperature siginificantly increased in 24hr. Intracerebral administration of LPS in dose range of 0.004-0.12 mg/100g did not significantly change the blood pressure in 24 hours. The heart rate and blood NOx were increased in a dose-dependenct manner that reached maximal level in 6h and recovered after 24h；Body temperature siginificantly increased in 24hr. Intracerebral administration of LPS in dose of 0.04 mg/100g got a maximal response and in dose of 0.12 mg/100g can not survive over 24hr which CSF NOx were slight increased in 3hr and 6hr.
In this study, the baroreflex function was not changed with peripheral administration, but were inhibited with peripheral administration. The maximal gain of baroreflex activity were decreased of rats at a dose of 0.04 mg/100g in 3rd、6rd and 24 rd from —1.969 to 0.037、—0.905 and 0.282 (n=8), and the curve for baroreflex ativity were shifted to the right from 146 ±3.56to 243.5±33.80 mmHg (n=8). In order to distingwish LPS inhibited effects of sympathetic and paresympathetic nerve on baroreflex function, “SNP” and “Phe” would be separate evaluated. We found that no matter sympathetic or paresympathetic were inhibited, especially after LPS 0.04 mg/100g administration in 3rd、6rd and 24rd on SNP or Phe induced baroreflex slope。 It was from 2.570.53 to 2.130.42、0.7160.27 and 1.350.45 (n=8) or from 2.540.31 to 2.160.29、3.140.35 and 2.180.28 m (n=8)。
All these results suggest that the production of NOx might stimulated the heart rate increase and fever in central and peripheral effects after LPS administration. The production of NOx might inhibited the baroreflex activities in central effects after LPS administration.
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