title: The activity of platelet activating factor-acetyl hydrolase (PAF-AH) in the salivary glands of Rhodnius prolixus.
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.
authors: Laboratório de Bioquímica e Fisiologia de Insetos, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (Fiocruz), Rio de Janeiro, Brazil.
authors: Rozana
authors: R
authors: Côrte-Real
authors: Raquel N
authors: RN
authors: Gomes
authors: Hugo C
authors: HC
authors: Castro-Faria-Neto
authors: Patricia
authors: P
authors: Azambuja
authors: Eloi S
authors: ES
authors: Garcia
mesh_terms: D043203:1-Alkyl-2-acetylglycerophosphocholine Esterase / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D005247:Feeding Behavior; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism*; D010972:Platelet Activating Factor / Q000378:metabolism; D010974:Platelet Aggregation; D012239:Rhodnius / Q000201:enzymology* / Q000235:genetics / Q000502:physiology; D012463:Saliva / Q000201:enzymology; D012469:Salivary Glands / Q000201:enzymology
chemical_list: D019476:Insect Proteins; D010972:Platelet Activating Factor; D043203:1-Alkyl-2-acetylglycerophosphocholine Esterase