当前位置： SCI文献检索 > ENDOCRINOLOGY期刊下所有文献 > Prostaglandin F2 alpha stimulates inositol 1,4,5-trisphosphate and inositol 1,3,4,5-tetrakisphosphate formation in bovine luteal cells.

Prostaglandin F2 alpha stimulates inositol 1,4,5-trisphosphate and inositol 1,3,4,5-tetrakisphosphate formation in bovine luteal cells.

Abstract：

:The present studies were conducted to further evaluate inositol phosphate formation and metabolism in prostaglandin F2 alpha (PGF2 alpha)-stimulated bovine luteal cells. Corpora lutea were dispersed with collagenase, and luteal cells were prelabeled for 3 h with [3H]inositol. Inositol phosphates produced in response to PGF2 alpha were analyzed by ion exchange column chromatography and HPLC. Time-course experiments revealed that significant increases in inositol trisphosphate (InsP3) were apparent within 5 sec of incubation with PGF2 alpha. Increases in inositol bisphosphate (InsP2) were also apparent within 5 sec. InsP1 and InsP4 were observed after a short (5-sec) lag period. HPLC revealed that PGF2 alpha provoked rapid (5 sec) increases in inositol 1,4,5-trisphosphate (Ins 1,4,5-P3), which was rapidly converted to inositol 1,3,4,5-tetrakisphosphate (Ins 1,3,4,5-P4) and inositol 1,3,4-trisphosphate (Ins 1,3,4-P3). The primary inositol bisphosphate isomer present in PGF2 alpha-stimulated bovine luteal cells was inositol 1,4-bisphosphate (Ins 1,4-P2), with lesser amounts of Ins 1,3-P2. Inositol monophosphates were also increased. These findings were confirmed in studies in which the metabolism of purified [3H]Ins 1,4,5-P3 was followed temporally in saponin-permeabilized bovine luteal cells. Additional studies demonstrated the presence of an enzyme, InsP3-3-kinase, in the cytosolic fraction of bovine corpora lutea. InsP3-3-kinase phosphorylated Ins 1,4,5-P3 to form Ins 1,3,4,5-P4. The activity of InsP3-3-kinase was calcium dependent and was enhanced by calmodulin at low calcium concentrations. Calmidazolium, a calmodulin inhibitor, reduced InsP3-3-kinase activity in a concentration-dependent manner. These results demonstrate the presence of multiple polyphosphorylated inositol phosphates in PGF2 alpha-stimulated bovine luteal cells. The isomers were formed via the action of a specific calcium/calmodulin-regulated kinase (InsP3-3-kinase), which phosphorylated Ins 1,4,5-P3 during agonist-mediated hydrolysis of phosphatidylinositol 4,5-bisphosphate. These data suggest that the inositol tris/tetrakisphosphate pathway is an important sequelae to PGF2 alpha-stimulated inositol phospholipid hydrolysis, and that the pathway may be activated during agonist-mediated calcium mobilization.

journal_name

Endocrinology

journal_title

Endocrinology

authors

Duncan RA,Davis JS

doi

10.1210/endo-128-3-1519

subject

Has Abstract

pub_date

1991-03-01 00:00:00

pages

1519-26

issue

eissn

0013-7227

issn

1945-7170

journal_volume

128

pub_type

杂志文章

在线工具

Prostaglandin F2 alpha stimulates inositol 1,4,5-trisphosphate and inositol 1,3,4,5-tetrakisphosphate formation in bovine luteal cells.