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 lar ge amounts of adenosine and 5'-AMP, of the order of 1 nmol per pair of glan ds, as demonstrated by liquid chromatography, ultraviolet spectrometry, mas s spectrometry and bioassays. These purines, 75-80 % of which are secreted from the glands following a blood meal, hare vasodilatory and anti-platelet activities and probably help the fly to obtain a blood meal. Salivary 5'-A MP is also responsible for the previously reported protein phosphatase inhi bitor in the salivary glands of P, papatasi, which is shown to be artifactu al in nature as a result of allosteric modification by AMP of the phosphata se substrate used (phosphorylase a).