Biological Characterization Of Crude Venom From Latrodectus Tredecimguttatus

Latrodectus tredecimguttatus, "black widow spider" or "blackvenomous spider", is one of medium-sized venomus spiders, whichbelongs to Phylum Arthopoda, Arachnidea, Araneae, Theridiidae, genusLatrodectus. The source of venom limited the research on it due to thevery low venom yield of the spider. Up to now, although a number ofstudies have described the biological properties and structures of severalvenomous proteins such asα-latrotoxin, the systematic property analysisof the venom from Latrodectus tredecimguttatus has less been reported.Inthe present paper, we have systematically analyzed the biologicalproperties of the venoms obtained by dissecting poison glands (VDPG)and electrical stimulation (VES) from Latrodectus tredecimguttatusindigenous to the some areas of the Xinjiang Uighur Autonomous Regionof China.Quantitative analysis indicated that the protein contents of VDPGand VES were 36.99% and 55.16%, respectively. The intraperitonealLD₅₀ values in mice of VES and VDPG were 0.16mg/kg and 0.39mg/kg,respectively. The intraperitoneal LD₅₀ value in cockroach of VDPG andVES were 2.32μg/g and 1.87μg/g, respectively. After intraperitonealinjection of the venom in mice, the main poisoning symptoms includedlethargy, ataxia, diaphoresis, convulsion, anorexia, shortness of breath,and difficulty to open eyes, etc. Whereas the mice injected withphysiological saline acted normally. After intraperitoneal injection of thevenom in cockroach, the main symptoms included lethargy, ataxia,convulsion, etc. Both of the venoms showed activities of multiplehydrolases including hyaluronidase, protease, DNase, acid phosphetase,alkaline phosphetase and choline esterase, of which hyaluronidase, protease and DNase were more active. The activity of protease in VDPGwas higher than that of protease in VES and the activities of the resthydrolases in VDPG were lower than those of hydrolases in VES. TheVDPG at a concentration of 10μg/mL was found to completely block theelectrically evoked contraction of the rat isolated vas deferens within 31min, and washout of the venom allowed partial recovery of thecontraction. VES at a concentration of 10μg/mL could block thecontraction within 17min, and washout of the venom allowed partialrecovery of the contraction. At a concentration of 6μg/mL, VDPG couldcompletely block neuromuscular transmission in a mouse isolated phrenicnerve diaphragm preparation within 25 min whereas VES of 3.2μg/mLcould completely block neuromuscular transmission in a mouse isolatedphrenic nerve diaphragm preparation within 23 min. Whole-cellpatch-clamp technology demonstrated that VDPG (1g/L) had notsignificant effects on the delayed-rectified K⁺ current, TTX-sensitive(TTX-S) Na⁺ current and high-voltage-activated Ca²⁺ current of rat dorsalroot ganglion (DRG) cells. The fast transiet K⁺ current of cottonbollworm dorsal DUM cells, the fast transiet K⁺ current, Na⁺ current andhigh-voltage-activated Ca²⁺ current of Periplaneta Americana dorsalunpaired median(DUM) cells were also not significantly affected byVDPG at the same concentration. However, VDPG had significant effecton the fast transiet K⁺ current of Pieris rapae. The VES had not significanteffects on the high-voltage-activated and low-voltage-activated Ca²⁺current of rat DRG cells.