Effect of hyperbaric oxygen on plasma calcitonin gene-related peptide and beta-enderphin levels in rats with transient global brain ischemia
- VernacularTitle:高压氧对短暂脑缺血大鼠血浆降钙素基因相关肽和β-内啡肽的影响
- Author:
Rui CHEN
;
Huifang FU
;
Yanguo TAN
- Publication Type:Journal Article
- From:
Chinese Journal of Tissue Engineering Research
2006;10(4):169-171
- CountryChina
- Language:Chinese
-
Abstract:
BACKGROUND: Prevention of tissue damage during early hours of cerebral ischemia has remained a major challenge in acute stroke management.Whether the application of hyperbaric oxygen (HBO) can protect cerebraltissue or not remains a question to be answered.OBJECTIVE: In cerebral ischemia-reperfusion rat model we studied the change on CGRP and β-endorphine levels and the therapeutic implication with hyperbaric oxygenation.DESIGN: A randomized controlled animal study.SETTING: Animal Research Department of Capital University of Medical Science.MATERIALS: The experiment was carried out at the Animal Research Department of the Capital University of Medical Science from December 2003 to February 2005. Sixty three healthy Sprague-Dewey female rats were randomly divided into 9 groups. There were 7 in the sham operation group. Four groups with 7 in each group received cerebral ischemia followed by reperfusion (IR) and blood sample taken at 6, 24, 48 and 96 hourrespectively. Another 4 groups (IR-HBO) with 7 in each received cerebral ischemia and reperfusion under hyperbaric oxgenation with blood sampling at 6, 24, 48 and 96 hours.INTERVENTIONS: With the exception of sham operation groups, animals in all the experimental groups were exposed to global cerebral is chemia of 20 minutes duration. Sham operation group and the IR groups remained under the normal atmospheric pressure. The HBO chamber was flushed with 100% oxygen for 5 minutes and raised the pressure in 5 minutes to a steady pressure at 0.2MPa. Rats in IR-HBO groups were put into the chamber with inhalation of 100% oxygen for 45 minutes and decompression was done for 15 minutes. The rats in HBO group were placed into the HBO chamber after 3-hour post reperfusion on the first day and this treatment was repeated for three consecutive days, always at the same time.Plasma was collected after 6 hours, 24 hours, 48 hours or 96 hours post cerebral reperfusion, respectively.MAIN OUTCOME MEASURES: The level of CGRP and β-EP in the plasma were measured by RIA (Radio-immunoassay).RESULTS: Sixty-three rats entered the final analysis. ① At 6-hour ischemia-repefusion: CGRP in HBO group was increased (64.12±18.16) ng/L and the onset time was earlier than that in IR group and the level was higher than those in IR group (32.62 ±11.72)ng/L and sham operation group (49.09±8.59)ng/L at the same time point (F=6.614, P ＜ 0.001, P ＜ 0.05). Β-EP level in 6-hour HBO group was slightly increased, but recovered at 24-hour, 48-hour, 96-hour HBO groups. ② At 24-hour and 48-hour ischemia-reperfusion: The plasma CGRP levels of the HBO group recover within 24-hours [(43.53±22.73)ng/L, F=0.390; (46.02±10.64)ng/L,F=0.969, P ＞ 0.05]. ③ 96-hour ischemia-reperfusion: CGRP increase in the IR group (81.74±20.64)ng/L was higher than that in the sham operation group (49.09±8.59)ng/L and the HBO group (40.98±20.52)ng/L at the same time point (F=6.419, P ＜ 0.01); and also obviously higher than those in 6-hour, 24-hour and 48-hour IR group (F=10.806, P ＜ 0.01).The β-EP level at 96-hour HBO group was decreased to the lowest as compared with that in the sham operation group [(370.00±130.15)ng/L,(872.30±403.92)ng/L, F=3.691, P ＜ 0.05].CONCLUSION: ① HBO in the early period of cerebral ischemia can reduce the onset of injury of cerebral tissue through increasing CGRP level and decreasing β-EP level; ②The more times treated by HBO, the better is its therapeutic effect.
