The activity of platelet activating factor-acetyl hydrolase (PAF-AH) in the salivary glands of Rhodnius prolixus

  • J Insect Physiol. 2011 Jun;57(6):825-9. doi: 10.1016/j.jinsphys.2011.03.016.
Rozana Côrte-Real  1 ,  Raquel N Gomes ,  Hugo C Castro-Faria-Neto ,  Patricia Azambuja ,  Eloi S Garcia
Affiliations
  • 1. Laboratório de Bioquímica e Fisiologia de Insetos, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (Fiocruz), Rio de Janeiro, Brazil.
PMID: 21439293 DOI: 10.1016/j.jinsphys.2011.03.016
Abstract

In this work, we investigated the activity of the platelet activating factor acetyl hydrolase (PAF-AH) in the salivary gland homogenates and saliva of Rhodnius prolixus. PAF-AH activity in the salivary gland homogenates was lower than in the saliva. Preliminary characterization of the enzyme demonstrated that it hydrolyzed the substrate 2-thio-PAF, was detectable just in 1 pair of salivary gland homogenates in 0.5 ml buffer, and was stable under different conditions. PMSF, TPCK, TLCK, pepstatin A and p-BPB all inhibited the PAF-AH activity. Enzyme specific activity in salivary gland homogenates diminished immediately after feeding of 5th-instar larvae, and increased before feeding by adult insects. 2-Thio-PAF induced platelet-aggregation that was inhibited by previous incubation of the substrate with salivary gland homogenates or saliva. The relevance of PAF-AH for providing Rhodnius with a feeding mechanism for facilitating the sucking of a high volume of blood meal in a short period is discussed.

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