In vitro expression and pharmacology of the 5-HT7-like receptor present in the mosquito Aedes aegypti tracheolar cells and hindgut-associated nerves

Authors


Patricia V. Pietrantonio, Associate Professor, Department of Entomology, Heep Center Room 412, Mail Stop 2475, Texas A & M University, College Station, TX 77843–2475, USA. Tel.: +1 979 845 9728; fax: +1 979 845 6305; e-mail: p-pietrantonio@tamu.edu

Abstract

We have previously reported the cloning of a 5-hydroxytryptamine receptor (Aedes 5-HT7-like receptor) from adult Aedes aegypti. For functional expression of the Aedes 5-HT7-like receptor, CHO-K1 cells were stably transfected with a receptor expression construct, pC5-HT7. The Aedes 5-HT7-like receptor positively coupled to Gs protein, increasing intracellular cAMP in response to 5-HT; adenylyl cyclase activity was induced in a concentration-dependent, saturable manner. Only 5-HT, and not octopamine, dopamine or tyramine, caused the induction of cAMP. At 10 nm 5-HT a weak synergism was observed between octopamine and 5-HT. Other known agonists of the mammalian 5-HT7 receptor were tested. Their order of potency was: 5-HT >> 5-CT = 8-OH-DPAT >> pimozide. This is the first report on the functional expression of a mosquito neurohormone receptor.

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