Kaufman W R
Department of Zoology, University of Alberta, Edmonton, Canada.
Exp Appl Acarol. 1990 Aug;9(1-2):87-95. doi: 10.1007/BF01198986.
Female ticks (Acari: Ixodidae) feed only once in the adult stage, dying after laying a large batch of eggs. During the early post-engorgement stage, haemolymph ecdysteroid titre rises, which is probably responsible for autolysis of the salivary glands that takes place at this time. Males, on the other hand, can re-attach and feed numerous times during the adult stage. Males were fed on rabbits for either 7 or 14 days. Haemolymph was collected either the day of removal from the host or 4 days later, and ecdysteroid titre was measured by radioimmunoassay. The approximate titre in all 4 groups was 20 ng of 20-hydroxyecdysone (20-OHE) equivalents/ml haemolymph. Fluid secretory competence in vitro can be used as an index of salivary-gland degeneration. The glands dissected from fed males which had been left off the host for 4 days lost 62% of their fluid secretory competence compared to glands dissected shortly after the males were removed. This loss in fluid secretory competence was reversed by allowing ticks left off the host of 4 days to resume feeding. Male salivary glands lost fluid secretory competence when exposed for 4 days in organ culture to 20-OHE; the effect was maximal at the lowest concentration tested (20 ng/ml). Thus, although male salivary glands were highly sensitive to 20-OHE, it is still not clear whether this hormone causes the tissue to degenerate.
雌性蜱虫（蜱螨亚纲：硬蜱科）在成年阶段仅进食一次，产卵大量后便死亡。在饱血后的早期阶段，血淋巴蜕皮甾类激素滴度升高，这可能是此时唾液腺自溶的原因。另一方面，雄性蜱虫在成年阶段可以多次重新附着并进食。雄性蜱虫以兔子为食7天或14天。在从宿主身上移除的当天或4天后采集血淋巴，并通过放射免疫测定法测量蜕皮甾类激素滴度。所有4组的近似滴度为每毫升血淋巴中含有20纳克20 -羟基蜕皮酮（20 - OHE）当量。体外液体分泌能力可作为唾液腺退化的指标。与刚从宿主身上移除后不久解剖的腺体相比，从已离开宿主4天的饱血雄性蜱虫身上解剖的腺体失去了62%的液体分泌能力。让离开宿主4天的蜱虫重新进食可逆转这种液体分泌能力的丧失。雄性唾液腺在器官培养中暴露于20 - OHE 4天时会失去液体分泌能力；在测试的最低浓度（20纳克/毫升）时效果最为明显。因此，尽管雄性唾液腺对20 - OHE高度敏感，但尚不清楚这种激素是否会导致组织退化。
