高压氧对幼鼠与成年鼠海马神经元超微结构影响的观察

目的 探讨高压氧（HBO）对正常幼鼠与成年鼠海马神经元超微结构的影响。方法 将健康SD幼鼠与成年大鼠暴露于0．25MPa(2．5ATA）HBO或高压空气（HBA）环境中1－3个疗程，各疗程结束当日取海马组织观察形态变化。结果 HBO处置引起海马组织内神经元核膜不平滑甚至模糊，部分线粒体肿胀、嵴模糊，部分粗面内质网（RER）扩张、脱颗粒。幼鼠1个疗程后可见轻微上述变化，处置次数增多，上述变化越明显；成年鼠2个疗程后出现神经元超微结构改变，但不及幼鼠显著。停止HBO处置后20d多数改变已恢复。HBA组明显改变。结论 长程HBO暴露可致大鼠海马组织内神经元超微结构损伤，相同方案HBO处置，幼鼠的结构改变早于成年鼠，且程度重、恢复时间相对要长；这种结构改变主要与HBO有关，非HBA所致，而且是可逆的。

Observation of the effect of hyperbaric oxygen on ultrastructure of neurons of hippocampus in infantile and adult rats

Objective To study the effect of hyperbaric oxygen on ultrastructure of neurons of hippocampus in infantile and adult rats. Methods Healthy SD infantile and adult rats were exposed to 0.25 MPa (2.5 ATA) HBO or hyperbaric air (HBA) for 1 to 3 courses (10 times a course ). The hip- pocampus was taken at the end of each course to observe its morphology by electron microscope. Results HBO exposure induced nuclear membrane winding or blurring of the hippocampus neurons with some mitochondria swelling and blurred crista. There were also some rough surfaced endoplasmic reticulum (RER) expansion and lose of granules in the neurons. These changes occured after 1 course of HBO ex- posure in infantile rats and became more evident with increased times of exposure. In adult rats, mito- chondria swelling was also observed after more than 2 courses of exposure but was less remarkable. 20 days after stopping of HBO exposure, most of the changes had recovered. While HBA exposure had caused no structural changes. Conclusions Long-term HBO exposure could injure the ultrastructure of neurons in rat hippocampus, but the damage is not serious and reversible: and these changes are more evident in infantile rats than those in adult rats.