碩士 / 國防醫學院 / 海底醫學研究所 / 91 / Diving acclimatization is a phenomenon that occurs when individuals undergoing daily compression decompression cycles, are able to reduce their susceptibility to acute decompression sickness( DCS).While the mechanism of diving acclimatization is not known, we proposed an “induction theory”,hypothesizing that the reduction of susceptibility is due to induction of protective factors in the body. During regular daily dives, “silent bubbles” do occur, without causing symptoms of DCS. These bubbles, however, may elicite some stress responses, in which “stress proteins ”will be expressed and several bioprotective mechanism may be activated.
We established an animal model of DCS in the rabbit to investigate the protective effect of heat stress on DCS and on the air bubble-induced lung injury. Heating animal to 42℃ of body temperature for 15 min induced heat stress as evidence by greater heat shock protein (HSP 70) expression. Experiencing a pressure cycle of 6 absolute atmosphere for 90min induced 43% DCS in 35 rabbits. The DCS induced a heat stress similar to that induced by elevation of body temperature. Heating—induced heat stress did not have a protective effect to the DCS as evaluated grossly by the occurrence of neurological and pulmonary signs of DCS. In contrast, DCS-induced heat stress did reduce the severity of DCS as evaluated by a published neurological physiology scale. Venous air infusion caused acute pulmonary embolism as evidence by pulmonary hypertension, increased dead space and shunt flow, greater wet to dry ratio of lung weight, and higher protein concentration in brochoalveolar lavage fluid. Heat shock induced HSP70 expression in liver and heart, but not in the lung. Heat shock pre-treatment did not reduce acute lung injury induced by venous air infusion. Our results showed that DCS can induced a heat stress response and, as it recovered by recompression therapy, can reduce physiological scale of DCS in the followed pressure exposure. We conclude that the induction of protective mechanism may be responsible for diving acclimatization。
| Identifer | oai:union.ndltd.org:TW/091NDMC0649001 |
| Date | January 2003 |
| Creators | Chien-Ling Su, 蘇千玲 |
| Contributors | Kun-Lun Huang, 黃坤崙 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 84 |
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