Lutzomyia longipalpis: pH in the gut, digestive glycosidases, and some speculations upon Leishmania development

Exp Parasitol. 1998 Nov;90(3):212-9. doi: 10.1006/expr.1998.4336.


Screening for digestive glycosidases in different parts of the gut and associated organs of Lutzomyia longipalpis is reported. Searches for the enzymes were made in blood-fed and non-blood-fed females and the enzymes were characterized as soluble or membrane-bound molecules. A total of four different activities were detected, corresponding to the following specificities: an alpha-glucosidase, an N-acetyl-beta-d-glucosaminidase, an N-acetyl-beta-d-galactosaminidase, and an alpha-l-fucosidase. Their possible role and importance for Leishmania development are discussed and the alpha-glucosidase enzyme was partially characterized. The pH inside the gut of non-blood-fed phlebotomines was measured with pH indicator dyes. The pH ranges obtained for crop, midgut, and hindgut were, respectively, higher than pH 6, pH 6, and lower than pH 6. A hypothesis concerning these data and Leishmania development is proposed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Carbohydrate Metabolism
  • Digestion
  • Female
  • Glycoside Hydrolases / analysis*
  • Glycoside Hydrolases / chemistry
  • Hydrogen-Ion Concentration
  • Insect Vectors / chemistry
  • Insect Vectors / enzymology*
  • Insect Vectors / parasitology
  • Leishmania / growth & development*
  • Nitrophenols / chemistry
  • Psychodidae / chemistry
  • Psychodidae / enzymology*
  • Psychodidae / parasitology
  • Solubility
  • Substrate Specificity


  • Nitrophenols
  • Glycoside Hydrolases
  • 4-nitrophenol