Inositol metabolism in WRK-1 cells. Relationship of hormone-sensitive to -insensitive pools of phosphoinositides
Previous studies have indicated the existence of two separate pools of phosphoinositides in WRK-1 cells; one is labile and hormone-sensitive with respect to turnover, while the other is stable. Hormonal stimulation results in a rapid increase in /sup 32/Pi incorporation into the sensitive pool, while in the absence of hormone, incorporation of /sup 32/Pi into this pool is slow. Results are quite different when (/sup 3/H)inositol is the precursor utilized. Incorporation of (/sup 3/H)inositol into hormone-sensitive phosphoinositides is not stimulated in the presence of hormone, suggesting entry of this exogenous precursor into the cycle by a route other than the resynthetic phase of the cycle. Furthermore, failure of hormone to induce loss of (/sup 3/H)phosphoinositide in pulse-chase experiments in the absence of lithium suggests reutilization of the (/sup 3/H)inositol moiety generated by phosphodiesteratic cleavage of hormone-sensitive phosphoinositide. Time course studies indicate that the relative rates of incorporation of (/sup 3/H)inositol into sensitive and insensitive phosphoinositide remain constant from 2 to 24 h. Several factors are capable of increasing (/sup 3/H)inositol incorporation into hormone-insensitive phosphoinositide including vasopressin, calcium ionophores, and manganese. On the other hand, vasopressin treatment appears to decrease incorporation of (/sup 3/H)inositol into the hormone-sensitive pool, probably by shifting the equilibrium between phosphoinositides and inositol phosphates, since the decrease in radioactivity observed in the phosphoinositides is equaled by the increase observed in that in the inositol phosphates.
- Research Organization:
- New York Univ. Medical Center, NY
- OSTI ID:
- 5726344
- Journal Information:
- J. Biol. Chem.; (United States), Vol. 262:27
- Country of Publication:
- United States
- Language:
- English
Similar Records
Vasopressin stimulates phosphoinositide hydrolysis in LLC-PK sub 1 cells
Influence of cyclic nucleotides (cAMP) on inositol phospholipid (InsPL) metabolism in cultured mesangial (MS) cells
Related Subjects
INOSITOL
METABOLISM
PHOSPHOLIPIDS
BIOLOGICAL FUNCTIONS
CHLORIDES
HORMONES
KINETICS
LITHIUM
PHOSPHATES
PHOSPHORUS 32
RESPONSE MODIFYING FACTORS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
ALKALI METALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CARBOHYDRATES
CHLORINE COMPOUNDS
DAYS LIVING RADIOISOTOPES
ELEMENTS
ESTERS
FUNCTIONS
HALIDES
HALOGEN COMPOUNDS
INOSITOLS
ISOTOPE APPLICATIONS
ISOTOPES
LABELLED COMPOUNDS
LIGHT NUCLEI
LIPIDS
METALS
MONOSACCHARIDES
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
OXYGEN COMPOUNDS
PHOSPHORUS COMPOUNDS
PHOSPHORUS ISOTOPES
RADIOISOTOPES
SACCHARIDES
550501* - Metabolism- Tracer Techniques