López-Johnston Juan C, de Bosch Norma, Scannone Héctor, Rodríguez-Acosta Alexis
Laboratorio de Investigaciones, Facultad de Farmacia, Universidad Central de Venezuela, Caracas, Venezuela.
J Thromb Thrombolysis. 2007 Dec;24(3):275-82. doi: 10.1007/s11239-007-0040-x. Epub 2007 May 8.
The Porthidium genus is represented by the P. lansbergii rozei and P. lansbergii hutmanni (Plh) subspecies in Venezuela. The venom components of these have been little studied, probably due to the low incidence of reported accidents, although acute and serious local effects such as invasive edema and disseminated ecchymosis are present during human envenonation. The aim of this work was to characterize the in vitro effects of crude P. l. hutmanni venom, and its fractions, on platelet aggregation triggered by two physiologic agonists: thrombin and collagen. The effects of thrombin and collagen were observed on a platelet-rich plasma (PRP) solution (3 x 10(5) platelets/microL) using serial dilutions of P. l. hutmanni venom (0.625-40 microg). The crude venom was fractionated by anionic exchange chromatography and two peaks obtained. Crude venom and both fractions were highly inhibitory on platelet aggregation mediated by the two agonists. The anti-aggregating dose (AD(50)) for both agonists was determined. PRP collagen-triggered aggregation was most inhibited by the crude venom (AD(50) = 0.67 microg) when compared with PRP thrombin-triggered aggregation (AD(50) = 4.92 microg). Collagen-induced aggregation was more intensely inhibited by venom than thrombin-induced aggregation. In conclusion, to specify the inhibition mechanisms involved for each of the active components in the venom from these subspecies, we must characterize and purify the inhibitors of aggregation from P. l. hutmanni venom, with the purpose of suggesting new pharmacological substances to be incorporated into the therapeutic arsenal to treat hemostatic pathologies related to high levels of platelet aggregation.
在委内瑞拉，波氏矛头蝮属由罗氏波氏矛头蝮和胡氏波氏矛头蝮（Plh）亚种代表。尽管人类被其咬伤时会出现如侵袭性水肿和弥漫性瘀斑等急性严重局部效应，但由于报告的咬伤事故发生率较低，对这些蛇毒的成分研究较少。本研究的目的是表征胡氏波氏矛头蝮粗毒及其组分对两种生理激动剂（凝血酶和胶原蛋白）引发的血小板聚集的体外作用。使用胡氏波氏矛头蝮毒液的系列稀释液（0.625 - 40微克），观察凝血酶和胶原蛋白对富血小板血浆（PRP）溶液（3×10⁵个血小板/微升）的影响。粗毒通过阴离子交换色谱法进行分离，得到两个峰。粗毒及其两个组分对两种激动剂介导的血小板聚集均具有高度抑制作用。确定了两种激动剂的抗聚集剂量（AD₅₀）。与凝血酶引发的PRP聚集（AD₅₀ = 4.92微克）相比，粗毒对胶原蛋白引发的PRP聚集抑制作用最强（AD₅₀ = 0.67微克）。毒液对胶原蛋白诱导的聚集的抑制作用比对凝血酶诱导的聚集更强。总之，为了明确这些亚种蛇毒中每种活性成分的抑制机制，我们必须对胡氏波氏矛头蝮毒液中的聚集抑制剂进行表征和纯化，目的是提出新的药理物质纳入治疗药库，以治疗与高水平血小板聚集相关的止血病理。
