The role of inositol 1,4,5-trisphosphate in mobilizing calcium from intracellular stores in the salivary glands of Amblyomma americanum (L.)

• Published in: Insect biochemistry Vol. 20; no. 1; pp. 83 - 89
• Main Authors: Roddy, Craig W., McSwain, Janis L., Kocan, Katherine M., Essenberg, Richard C., Sauer, John R.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier B.V 1990; New York, NY Pergamon Press
• Subjects: AMBLYOMMA; Arachnida; Biochemistry. Physiology. Immunology; Biological and medical sciences; CALCIO; CALCIUM; FOSFATOS; Fundamental and applied biological sciences. Psychology; GLANDE SALIVAIRE; GLANDULAS SALIVALES; INOSITOL; Invertebrates; PHOSPHATE; PHOSPHATES; Physiology. Development; SALIVARY GLANDS; MOPS; HEPES; IP 3; tick salivary glands; IP 1; IP 2; inositol phosphates; calcium moblization; EGTA; Parasitiformes; Fractionation; Inositol; Calcium; Salivary gland; Inositol phosphate; Mobilization; Arachnida; Absorption; Transmission electron microscopy; Acari; Ixodida; Arthropoda; Amblyomma americanum; Cations; Intracellular; Invertebrata; Derived product; Ixodidae
• ISSN: 0020-1790
• DOI: 10.1016/0020-1790(90)90023-N

Isolated tick salivary glands, permeabilized with digitonin in the presence of the Ca 2+ uptake inhibitors, sodium azide and vanadate, released Ca 2+ in response to 20 μM inositol-1,4,5-trisphosphate (IP 3). Inositol-1-phosphate (IP 1) and inositol-1,4-bisphosphate (IP 2) appeared to stimulate an uptake of Ca 2+ into whole glands. Inositol-1,4,5-trisphosphate caused release of Ca 2+ from a 100,000 g microsome enriched pellet; however, IP 1 and IP 2 were ineffective in stimulating an uptake or efflux of Ca 2+. The combined 900 and 11,500 g pellets showed no significant release of Ca 2+ in response to addition of IP 3. Inositol-1,4,5-trisphosphate concentrations as low as 1 μM are capable of stimulating a significant release of Ca 2+ from microsomes. Results suggest that intracellular Ca 2+ is mobilized from microsomal intracellular stores in response to agonists which increase cytosolic IP 3 in tick salivary glands. Results also suggest a possible role for IP 1 and IP 2 or both in stimulating an uptake of Ca 2+ into vanadate and azide-insensitive intracellular pools.