5-HYDROXYTRYPTAMINE IN THE SALIVARY GLANDS OF ADULT FEMALE AEDES AEGYPTI AND ITS ROLE LN REGULATION OF SALIVATION

摘要

A dense plexus of axons, immunoreactive to antisera against 5-hydroxytryptamine (5-HT, serotonin) and surrounding the proximal medial lobe of the salivary gland of adult female Aedes aegypti mosquitoes, was demonstrated by means of whole-mount fluorescence immunocytochemistry. This innervation originates in the stomatogastric nervous system. 5-HT-immunoreactive innervation is absent in male salivary glands, suggesting that 5-HT is involved in blood-feeding, Furthermore, female mosquitoes treated with the 5-HT-depleting agent alpha-methyltryptophan (AMTP) and then allowed to feed on a rat exhibited a significantly longer mean probing period and a lower blood-feeding success rate than did control mosquitoes, When female mosquitoes were experimentally induced to salivate into mineral oil, AMTP-treated individuals secreted significantly less saliva than did control mosquitoes, These samples of saliva also contained significantly lower concentrations of apyrase, an enzyme important in blood-feeding, Injection of 5-HT into both AMTP-treated and control mosquitoes elicited significant increases in the volume of secreted saliva and/or its apyrase content, We conclude that 5-HT plays an important role in the control of salivation in adult female A. aegypti. [References: 31]