Formation and metabolism of inositol 1,4,5 trisphosphate in human platelets

Conference · Fri May 01 00:00:00 EDT 1987 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:6125160

Daniel, J L; Dangelmaier, C A; Smith, J B

(/sup 3/H)Myo-inositol (1,4,5)trisphosphate ((1,4,5)IP/sub 3/), when added to lysed platelets, was rapidly converted to (/sup 3/H)inositol (1,3,4,5)tetrakisphosphate which was in turn converted to (/sup 3/H)inositol (1,3,4)trisphosphate. This result demonstrates that platelets have the same metabolic pathways for interconversion of inositol polyphosphates that are found in other cells. Labelling of platelets with (/sup 32/P)orthophosphate, followed by h.1.p.c. was used to measure thrombin-induced changes in the three inositol polyphosphates. Interfering compounds were removed by a combination of enzymatic and nonenzymatic techniques. (/sup 32/P)-(1,4,5)IP/sub 3/ was formed rapidly and reached its maximal level at about 4 sec. It was also rapidly degraded and was no longer detectable after 30-60 sec. Formation of (1,3,4,5)IP/sub 4/ was almost as rapid as that of (1,4,5)IP/sub 3/ and remained at detectable levels for a longer time. (1,3,4)IP/sub 3/ was formed after an initial lag and this isomer reached its maximal level that was ten-fold higher than that of (1,4,5)IP/sub 3/ at 30 sec. Comparison of the intracellular Ca/sup 2 +/ concentration as measured with fura-2 indicates that agents other than (1,4,5)IP/sub 3/ are responsible for the sustained maintenance of a high level of intracellular Ca/sup 2 +/. It is proposed that either (1,3,4)IP/sub 3/ or (1,3,4,5)IP/sub 4/ may also be Ca/sup 2 +/-mobilizing agents.

• Research Organization: Temple Univ., Philadelphia, PA
• OSTI ID: 6125160
• Report Number(s): CONF-870644-; TRN: 87-034063
• Journal Information: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Vol. 46:6; Conference: 78. annual meeting of the American Society of Biological Chemists conference, Philadelphia, PA, USA, 7 Jun 1987
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
INOSITOL
METABOLISM
BIOLOGICAL PATHWAYS
BLOOD PLATELETS
CALCIUM COMPOUNDS
MAN
PHOSPHORUS 32
TRACER TECHNIQUES
TRITIUM COMPOUNDS
ALKALINE EARTH METAL COMPOUNDS
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY FLUIDS
CARBOHYDRATES
DAYS LIVING RADIOISOTOPES
INOSITOLS
ISOTOPE APPLICATIONS
ISOTOPES
LABELLED COMPOUNDS
LIGHT NUCLEI
MAMMALS
MATERIALS
MONOSACCHARIDES
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
PHOSPHORUS ISOTOPES
PRIMATES
RADIOISOTOPES
SACCHARIDES
VERTEBRATES
550501* - Metabolism- Tracer Techniques