大鼠腹腔海水浸泡时间与死亡率的关系

目的 观察海水浸泡大鼠腹腔对大鼠急性死亡的影响,分析浸泡时间与死亡率的关系。方法:选取SD大鼠40只,随机分为对照组(等渗盐水腹腔浸泡组)及海水腹腔浸泡组,每组20只,观察腹腔浸泡后大鼠急性死亡情况。结果:对照组持续浸泡2小时均无死亡,海水腹腔浸泡组持续浸泡67min50％大鼠急性死亡,浸泡95min全部急性死亡。结论:海水腹腔浸泡可以引起大鼠急性死亡,死亡率随着海水浸泡时间的延长而增高。     

海水浸泡对犬弹烧复合伤伤情特点的影响

目的研究海水浸泡对弹烧复合伤动物的致伤特点，方法成功建立海水浸泡弹烧复合伤模型后，依模型将15只成年杂种犬随机分为单纯弹烧复合伤组(简称非浸泡组)7只和海水浸泡弹烧复合伤组(简称浸泡组)8只．动态监测伤前、伤后4．7．10，20，28h共6个时相点体温(T)、心率(HR)、平均动脉压(MAP)、平均肺动脉压(MPAP)、中心静脉压(CVP)、肺毛细血管楔压(PCWP)、心脏指数(CI)．计算每搏输出指数(SVI)、外周循环阻力指数(SVRI)、肺循环阻力指数(PVRI)、左室每搏功输出指数(LVSWI)、右室每搏功输出指数(RVSWI)。结果动物海水浸泡后，体温明显降低；心率、平均动脉压、中心静脉压、肺毛细血管楔压、心脏指数、每搏输出指数明显下降；外周循环阻力指数、肺循环阻力指数明显增高；左室每搏功输出指数、右室每搏功输出指数明显下降。结论海水浸泡明显加重动物伤情。实验动物中心体温明显下降；血流动力学紊乱明显加重，休克出现早．致动物死亡时间提前．死亡率增高。     

海水浸泡对大鼠晶状体Na+,K+-ATP酶表达的影响

目的研究大鼠晶状体海水浸泡伤后Na^＋，K^＋浓度和Na^＋，K^＋-ATP酶在mRNA水平的表达与形态学损伤之间的关系。方法用逆转录聚合酶链式反应法测定大鼠晶状体Na^＋，K^＋-ATP酶α亚单位在mRNA水平的表达状况，并与Na^＋，K^＋浓度和超微结构的变化进行对比分析。结果海水浸泡大鼠晶状体Na^＋，K^＋-ATP酶的α1，α2，α3亚单位mRNA水平的表达首先代偿性增高，随后呈失代偿性降低，并随时间的延长而逐渐降低。海水浸泡30min缝合伤口观察1周组的α1及α2亚单位的表达高于对照组，α3亚单位的表达基本恢复正常。结论在晶状体海水浸泡伤的病变过程中，Na^＋，K^＋-ATP酶亚单位活性的表达有不同变化。     

应激性胃粘膜损害的实验研究(垂体-肾上腺系统与应激性胃粘膜损害)

研究大鼠在束缚-浸水应激情况下,血清胃泌素值的变化,胃粘膜损害情况及其与垂体-肾上腺系统的关系。结果表明,大鼠注射地塞米松或切除肾上腺后,对束缚-浸水紧张性刺激引起的血清胃泌素值增高及应激性胃粘膜损害的形成与对照组相比较均无显著性差异。提示在束缚-浸水应激性胃粘膜损害形成的机制中,垂体-肾上腺系统可能不起重要作用。     

Skeletal muscle activity of alcohol-treated rabbitts in immersion hypothermia: Adenine nucleotide concentrations and phosphorylation state

Summary The effects of alcohol injection (0.5 g·kg^–1i.v.) on the core cooling and rewarming rates, concentration of the adenine nucleotides, and the phosphorylation state of the adenylate system (ATP/ADP×P) were studied in the skeletal muscle of anesthetized rabbits immersed in ice-cold water. NaCl-injected rabbits immersed in ice-cold water were used as cold controls, alcohol-treated animals at room temperature (20°C) as alcohol warm controls, and NaCl-injected animals at room temperature as anesthesia controls, respectively.The fall of core temperature to 32°C in the alcohol-treated rabbits and the cold controls took about 40 min. During this time the temperature of the alcohol warm and anesthesia controls fell by about 1°C. No difference in the rewarming rate was observed between the alcohol-treated and cold control rabbits.Serum glucose concentration was elevated in the cold controls (from 5.9 to 8.3 mmol/l) but not in the alcohol-treated rabbits.Cold exposure reduced the phosphorylation state in the skeletal muscle of the alcohol-treated rabbits by 32% (P<0.05), but the decrease (6%) was not significant in the cold controls. After rewarming the phosphorylation state decreased in the above groups by 71% and 15%, respectively, as compared with the initial values. No significant changes in the phosphorylation state were found in the warm control animals.The redox state of the cytosol in the skeletal muscle or liver did not change, nor was there any change observed in the arterial pO₂ or pCO₂ concentrations.In conclusion, the results suggest an increased skeletal muscle activity during immersion hypothermia in alcohol-treated rabbits, but not in the controls.Dedicated to Professor W. Janssen on the occasion of his 60th birthday     

Renal hemodynamics and natriuresis during water immersion in normal humans

The renal vascular and functional responses to acute central hypervolemia by water immersion to the neck were determined in six normal subjects. During isotonic-isooncotic expansion by water immersion there was a significant increase in urine flow from 1.1±0.1 to 6.9±1.0 ml/min (p<0.05) and sodium excretion from 99.1±8.8 to 300±28 Eq/min (p<0.05). Glomerular filtration rate did not change while renal blood flow significantly increased during water immersion. Deep intrarenal venous pressure (IRVP) increased from 18.2±1.4 to 32±1.7 mmHg (p<0.05) while mean arterial pressure was unchanged. This marked natriuresis seen during water immersion was associated with reduced renal vascular resistance and increased deep intrarenal venous pressure demonstrating that continued natriuresis could relate to increased capillary hydrostatic pressure.     

Factors which affect shivering in man during cold water immersion

Six subjects were immersed in cold water (15.15±0.42°C) and were asked to perform two tasks. Shivering elicited by the cold water immersion was attenuated and/or abolished by the mental arithmetic task and in some instances by a voluntary isometric contraction of forearm muscles. Some reasons for these results are discussed.     

肾上腺素对低温海水浸泡失血性休克大鼠血压的影响

目的:探讨肾上腺素对低温海水浸泡失血性休克大鼠平均动脉压和心率的影响及其机制。方法:成年雄性SD大鼠28只随机分为4组:正常组(N组,常温未作任何处理),肾上腺素组(E组,常温下失血性休克后注射肾上腺素),低温海水浸泡失血性休克+生理盐水组(DSN组),低温海水浸泡失血性休克+肾上腺素组(DSE组),每组7只,检测平均动脉压(MAP)和心率(HR)。结果:注射肾上腺素后,DSE组MAP前、中期高于正常组,末期迅速下降并低于正常组,但高于注射药物前的血压。E组血压发生了双向性变化。结论:低温海水浸泡失血性休克大鼠注射肾上腺素未能引起血压的双向性变化。     

不同海水浸泡时间对左氧氟沙星在腹部开放伤比格犬体内的药动学影响

目的建立腹部开放性创伤合并海水浸泡比格犬动物模型,研究左氧氟沙星（LVFX）在腹部开放性损伤合并海水浸泡比格犬与正常比格犬中的药动学变化。方法 12只比格犬随机分为3组,每组4只。A组为正常对照组,B组为腹部开放性创伤合并海水浸泡45 min组,C组为腹部开放性创伤合并海水浸泡90 min组。3组动物给药方案为：静脉输注LVFX25 mg/kg,60 min输注完毕。实验进程中监测实验动物体温。采用HPLC测定LVFX浓度;3P97计算药动学参数。结果腹部开放性创伤合并海水浸泡比格犬在浸泡过程中和出水后体温显著下降,且随浸泡时间增加而下降幅度增加。LVFX在比格犬体内呈二室模型,A、B和C组药动学参数分别为：Cmax（30.05±1.75）、（36.10±4.74）和（42.34±4.19）mg/L,t1/2β（8.23±0.65）、（11.02±0.54）和（13.19±3.87）h,AUC（247.00±14.10）、（345.22±56.68）和（417.79±83.32）mgoh/L,Vc（6.97±2.02）、（6.68±1.67）和（7.82±1.62）L,ClS（1.20±0.15）、（1.06±0.12）和（0.92±0.15）L/h。与A组比较,B组t1/2β和AUC显著增加（P〈0.05）;C组t1/2β、Cmax和AUC（t1/2β,P〈0.01;Cmax,AUC,P〈0.05）显著增加。与B组比较,C组t1/2β（P〈0.05）差异明显。结论腹部开放性创伤合并海水浸泡比格犬体内LVFX代谢消除随浸泡时间延长而明显减慢,其机制可能与浸泡导致的低体温状况有关。