Rash L D, King R G, Hodgson W C
Monash Venom Group, Department of Pharmacology, Monash University, Clayton, Australia.
Toxicon. 2000 Aug;38(8):1111-27. doi: 10.1016/s0041-0101(99)00226-3.
This study compared the pharmacological activity of venom from male and female white-tailed spiders (L. cylindrata). In guinea-pig ileum, male L. cylindrata venom (1-10 microg/ml) caused dose-dependent contractions. The response to venom (5 microg/ml) was significantly inhibited by mepyramine (0.5 microM). Venom (5-50 microg/ml) from female L. cylindrata had no contractile activity in this tissue. However, female L. cylindrata venom (50 microg/ml) inhibited electrically-evoked twitches of guinea-pig ileum. This inhibitory effect was attenuated by 8-phenyltheophylline (10 microM) or by prior exposure of venom to adenosine deaminase. In the rat vas deferens, male (5 microg/ml) and female (50 microg/ml) L. cylindrata venom inhibited electrically-evoked twitches. 8-Phenyltheophylline (20 microM) significantly attenuated the response to female L. cylindrata venom, while the histamine H(2)- and H(3)-receptor antagonists ranitidine (10 microM) and thioperamide (0.2 microM) significantly attenuated the response to male L. cylindrata venom. Male L. cylindrata venom (5-20 microg/ml) caused dose-dependent contractions in the epididymal segment of the rat vas deferens. The response to male L. cylindrata venom (10 microg/ml) was significantly inhibited by prazosin (0.3 microM) but was unaffected by depleting monoamine stores with reserpine. Male L. cylindrata venom (5-15 microg/ml) caused dose-dependent increases in rate and force of rat atria which were significantly inhibited by propranolol (5 microM) but not by reserpine. Female L. cylindrata venom (50 microg/ml) had no effect in atria. In the anaesthetised (pentobarbitone, 100 mg/kg, i.p.) rat, male L. cylindrata venom (10-300 microg/kg, i.v.) caused dose-dependent depressor responses while venom (up to 1 mg/kg, i.v.) from female L. cylindrata had no effect on arterial pressure. A histamine content of 5 and 0.01% (dry weight) was detected in venom from male and female L. cylindrata, respectively. Venom from male L. cylindrata was found to contain 56 pg noradrenaline/microg whereas venom from the female contained negligible noradrenaline. The results of this study show the presence of histamine and noradrenaline in venom from male L. cylindrata. Although devoid of significant quantities of these amines, female L. cylindrata venom has activity at adenosine receptors.
本研究比较了雄性和雌性白尾蜘蛛（L. cylindrata）毒液的药理活性。在豚鼠回肠中，雄性L. cylindrata毒液（1 - 10微克/毫升）引起剂量依赖性收缩。对毒液（5微克/毫升）的反应被美吡拉敏（0.5微摩尔）显著抑制。雌性L. cylindrata毒液（5 - 50微克/毫升）在该组织中无收缩活性。然而，雌性L. cylindrata毒液（50微克/毫升）抑制豚鼠回肠的电诱发抽搐。这种抑制作用被8 - 苯基茶碱（10微摩尔）或毒液预先暴露于腺苷脱氨酶所减弱。在大鼠输精管中，雄性（5微克/毫升）和雌性（50微克/毫升）L. cylindrata毒液抑制电诱发抽搐。8 - 苯基茶碱（20微摩尔）显著减弱对雌性L. cylindrata毒液的反应，而组胺H(2) - 和H(3) - 受体拮抗剂雷尼替丁（10微摩尔）和硫代哌酰胺（0.2微摩尔）显著减弱对雄性L. cylindrata毒液的反应。雄性L. cylindrata毒液（5 - 20微克/毫升）在大鼠输精管附睾段引起剂量依赖性收缩。对雄性L. cylindrata毒液（10微克/毫升）的反应被哌唑嗪（0.3微摩尔）显著抑制，但不受利血平耗尽单胺储存的影响。雄性L. cylindrata毒液（5 - 15微克/毫升）引起大鼠心房率和力的剂量依赖性增加，这被普萘洛尔（5微摩尔）显著抑制，但不受利血平影响。雌性L. cylindrata毒液（50微克/毫升）对心房无作用。在麻醉（戊巴比妥，100毫克/千克，腹腔注射）大鼠中，雄性L. cylindrata毒液（10 - 300微克/千克，静脉注射）引起剂量依赖性降压反应，而雌性L. cylindrata毒液（高达1毫克/千克，静脉注射）对动脉血压无影响。在雄性和雌性L. cylindrata毒液中分别检测到组胺含量为5%和0.01%（干重）。发现雄性L. cylindrata毒液含有56皮克去甲肾上腺素/微克，而雌性毒液中去甲肾上腺素含量可忽略不计。本研究结果表明雄性L. cylindrata毒液中存在组胺和去甲肾上腺素。尽管雌性L. cylindrata毒液不含大量这些胺类，但它在腺苷受体上有活性。
