Shohami E, Shapira Y, Cotev S
Department of Pharmacology, Hadassah University Hospital, Jerusalem, Israel.
Neurosurgery. 1988 May;22(5):859-63.
In a model of closed head injury in rats, a calibrated weight drop device was allowed to fall onto the skull's convexity over the left hemisphere 1 to 2 mm lateral from the midline. Prostaglandin (PG) levels were determined in the frontal cortex region remote from the site of injury where no macroscopic damage could be seen. Differential patterns of temporal changes were evident for PGE2, PGD2, thromboxane (TX) B2, and 6-keto-PGF1 alpha in the contused hemisphere, but no changes were found in the contralateral hemisphere. The major changes in PG levels were increased levels of PGD2 and 6-keto-PGF1 alpha that persisted from 18 hours until 10 days after injury. The ratio between TXB2 and 6-keto-PGF1 alpha, which reflects the vascular tone, increased during the early postinjury period (15 minutes and 1 hour) and decreased later, up to 10 days. Thus, a sustained imbalance in favor of the vasodilator is apparent; this may suggest an improved blood supply to the region. Both PGD2 and PGI2 have protective effects in the brain. We suggest that their endogenous increase may be part of a repair mechanism at the periphery of the injured zone.
在大鼠闭合性颅脑损伤模型中，使用校准过的重物下落装置，使其从距中线外侧1至2毫米处落在左半球颅骨的凸面上。在远离损伤部位且未见明显宏观损伤的额叶皮质区域测定前列腺素（PG）水平。在挫伤半球中，前列腺素E2（PGE2）、前列腺素D2（PGD2）、血栓素（TX）B2和6-酮-前列腺素F1α（6-keto-PGF1α）呈现出明显的时间变化差异模式，但在对侧半球未发现变化。PG水平的主要变化是PGD2和6-keto-PGF1α水平升高，这种升高在损伤后18小时至10天持续存在。反映血管张力的TXB2与6-keto-PGF1α的比值在损伤后早期（15分钟和1小时）升高，随后下降，直至10天。因此，明显存在有利于血管舒张剂的持续失衡；这可能表明该区域的血液供应得到改善。PGD2和前列环素（PGI2）在脑内均具有保护作用。我们认为它们的内源性增加可能是损伤区域周边修复机制的一部分。
