Salivary glands of the sand fly Phlebotomus papatasi contain pharmacologically active amounts of adenosine and 5′-AMP

Salivary gland homogenates of the sand fly Phlebotomus papatasi contain large amounts of adenosine and 5′-AMP, of the order of 1 nmol per pair of glands, as demonstrated by liquid chromatography, ultraviolet spectrometry, mass spectrometry and bioassays. These purines, 75–80 % of which are secreted from the glands following a blood meal, have vasodilatory and anti-platelet activities and probably help the fly to obtain a blood meal. Salivary 5′-AMP is also responsible for the previously reported protein phosphatase inhibitor in the salivary glands of P. papatasi, which is shown to be artifactual in nature as a result of allosteric modification by AMP of the phosphatase substrate used (phosphorylase a).