Department of Pharmacology, Monash University, Victoria, Australia.
Toxicol Lett. 2010 Feb 15;192(3):419-24. doi: 10.1016/j.toxlet.2009.11.019. Epub 2009 Nov 27.
Chironex fleckeri (box jellyfish) are found in the northern tropical waters of Australia. Although C. fleckeri have a wide geographical distribution and are able to swim large distances, adults tend to stay in small restricted areas. Clinical data shows that deaths from envenoming have not been recorded in Western Australia, yet numerous fatalities have occurred in Northern Territory and Queensland waters. One explanation for this discrepancy is a geographical variation in venom composition. This study examined the pharmacological and biochemical profiles of C. fleckeri venom from different geographical locations and seasons. Venoms were screened for cytotoxicity using a rat aortic smooth muscle cell line (A7r5). While all venoms caused concentration-dependent cytotoxicity, differences were seen in the potency of venoms from Mission Beach and Weipa, when collected in different seasons, as indicated by IC(50) values. Similarly venoms collected within the same season, from different locations around Australia, displayed marked differences in venom composition as shown by size exclusion HPLC and SDS-PAGE profiles which indicated the absence or reduced quantity of 'peaks' in some venoms. Based on IC(50) data obtained from the cell assay, the effects of the most potent (i.e. from Weipa in 2006) and the least potent (i.e. from Broome in 2007) venoms were examined in anesthetised rats. Both venoms at 10 microg/kg (i.v.) caused a transient hypertensive phase followed by cardiovascular collapse. However, at 4 microg/kg (i.v.) venom from Weipa 2006 caused a transient hypertensive phase followed by a transient decrease in MAP while venom from Broome 2007 only caused a small transient increase in MAP. This study demonstrates that there is considerable geographical variation in the composition of C. fleckeri venoms which is most distinct between specimens from western and eastern Australia and may explain the geographical variation in reported deaths.
箱型水母（Chironex fleckeri）分布于澳大利亚北部热带海域。尽管箱型水母分布范围广泛，能够长距离游动，但成年个体往往局限于小范围海域。临床数据显示，西澳大利亚州尚未有因箱型水母螫伤致死的记录，但北领地和昆士兰州海域却发生了多起死亡病例。这种差异的一个解释是毒液成分存在地域差异。本研究检测了来自不同地理区域和不同季节的箱型水母毒液的药理学和生物化学特征。采用大鼠主动脉平滑肌细胞系（A7r5）检测毒液的细胞毒性。所有毒液均引起浓度依赖性的细胞毒性，但采自米申海滩和威帕的毒液在不同季节时，其效力存在差异，这一点可以从半数抑制浓度（IC50）值中看出。同样，在同一季节、来自澳大利亚不同地区的毒液，在大小排阻高效液相色谱法和 SDS-PAGE 图谱中显示出明显的毒液组成差异，这表明某些毒液中“峰”的缺失或数量减少。基于细胞测定中获得的 IC50 数据，研究了从麻醉大鼠中获得的最有效毒液（即 2006 年来自威帕的毒液）和最无效毒液（即 2007 年来自布鲁姆的毒液）的作用。两种毒液在 10 μg/kg（静脉注射）时均引起短暂的高血压期，随后发生心血管衰竭。然而，在 4 μg/kg（静脉注射）时，来自威帕的毒液在引起短暂的高血压期后，MAP 短暂下降，而来自布鲁姆的毒液仅引起 MAP 短暂轻微升高。本研究表明，箱型水母毒液的组成存在显著的地域差异，来自澳大利亚西部和东部的标本之间的差异最为明显，这可能解释了报道的死亡病例的地域差异。
