A Novel Method for Prostaglandin Endoperoxide H Synthase Activity in Individual Intact Cells

1997 ◽  
pp. 521-524 ◽  
Author(s):  
Ikuo Morita ◽  
Melvin Schindler ◽  
David DeWitt ◽  
Sei-itsu Murota ◽  
William Smith
Keyword(s):  
Intact Cells ◽  
Prostaglandin Endoperoxide ◽  
Novel Method ◽  
Endoperoxide H Synthase

scholarly journals Low viscosity in the aqueous domain of cell cytoplasm measured by picosecond polarization microfluorimetry.

1991 ◽  
Vol 112 (4) ◽  
pp. 719-725 ◽  
Author(s):  
K Fushimi ◽  
A S Verkman
Keyword(s):  
Free Water ◽  
Fluid Phase ◽  
Rotational Correlation Time ◽  
Cell Cytoplasm ◽  
Intact Cells ◽  
Low Viscosity ◽  
3T3 Fibroblasts ◽  
Anisotropy Decay ◽  
Novel Method ◽  
Swiss 3T3 Fibroblasts

Information about the rheological characteristics of the aqueous cytoplasm can be provided by analysis of the rotational motion of small polar molecules introduced into the cell. To determine fluid-phase cytoplasmic viscosity in intact cells, a polarization microscope was constructed for measurement of picosecond anisotropy decay of fluorescent probes in the cell cytoplasm. We found that the rotational correlation time (tc) of the probes, 2,7-bis-(2-carboxyethyl)-5-(and-6-)carboxyfluorescein (BCECF), 6-carboxyfluorescein, and 8-hydroxypyrene-1,3,6-trisulfonic acid (HPTS) provided a direct measure of fluid-phase cytoplasmic viscosity that was independent of probe binding. In quiescent Swiss 3T3 fibroblasts, tc values were 20-40% longer than those in water, indicating that the fluid-phase cytoplasm is only 1.2-1.4 times as viscous as water. The activation energy of fluid-phase cytoplasmic viscosity was 4 kcal/mol, which is similar to that of water. Fluid-phase cytoplasmic viscosity was altered by less than 10% upon addition of sucrose to decrease cell volume, cytochalasin B to disrupt cell cytoskeleton, and vasopressin to activate phospholipase C. Nucleoplasmic and peripheral cytoplasmic viscosities were not different. Our results establish a novel method to measure fluid-phase cytoplasmic viscosity, and indicate that fluid-phase cytoplasmic viscosity in fibroblasts is similar to that of free water.

scholarly journals Fatty Acid Substrate Specificities of Human Prostaglandin-endoperoxide H Synthase-1 and −2

1995 ◽  
Vol 270 (33) ◽  
pp. 19330-19336 ◽  
Author(s):  
Odette Laneuville ◽  
Debra K. Breuer ◽  
Naxing Xu ◽  
Z. H. Huang ◽  
Douglas A. Gage ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Substrate ◽  
Substrate Specificities ◽  
Prostaglandin Endoperoxide ◽  
Endoperoxide H Synthase ◽  
Acid Substrate

scholarly journals Tumour necrosis factor-alpha stimulates increased expression of prostaglandin endoperoxide H synthase Type 2 mRNA in amnion-derived WISH cells

1998 ◽  
Vol 20 (2) ◽  
pp. 221-231 ◽  
Author(s):  
WR Hansen ◽  
T Sato ◽  
MD Mitchell
Keyword(s):  
Tumour Necrosis Factor ◽  
Tumour Necrosis ◽  
Tumour Necrosis Factor Alpha ◽  
Early Gene ◽  
Tnf Alpha ◽  
Necrosis Factor Alpha ◽  
Prostaglandin Endoperoxide ◽  
Factor Alpha ◽  
Endoperoxide H Synthase ◽  
Necrosis Factor

We have evaluated the mechanism by which tumour necrosis factor-alpha (TNF-alpha) induces increased prostaglandin (PG) biosynthesis in amnion-derived WISH cells. WISH cells were treated with 50 ng/ml TNF-alpha or vehicle for 0-24 h. PGE2 production was stimulated by TNF-alpha within 2 h and continued to accumulate for at least 24 h. Increased prostaglandin endoperoxide H synthase (PGHS)-2 mRNA expression was evident within 30 min and was highest by 1 h, returning to unstimulated levels by 2 h. The PGHS-2 mRNA was re-induced at 8 h and was also elevated at 16 h. Immunoreactive PGHS-2 protein was nearly undetectable in control cells. However, within 30 min of TNF-alpha treatment, PGHS-2 protein was elevated and was induced for at least 16 h suggesting rapid production of both the PGHS-2 mRNA and protein. Transcription run-on assays indicated that the initial increase in the PGHS-2 mRNA was due to a 20-fold increase in the rate of transcription. The PGHS-2 mRNA decayed with an apparent half-life of 1 h in TNF-alpha-stimulated WISH cells. Induction of PGHS-2 expression proceeded in the presence of 10 microg/ml cycloheximide which agrees with the classification of PGHS-2 as an immediate early gene. These results indicate that a bi-phasic induction of the PGHS-2 mRNA is due, in part, to an initial transcriptional activation which results in rapid and continued synthesis of the PGHS-2 protein. This may be a unique characteristic of amnion cells which may be partially responsible for increased PG concentrations in the amniotic fluid during infection-associated preterm labour.

Expression of prostaglandin endoperoxide H synthase‐2 induced by nitric oxide in conditionally immortalized murine colonic epithelial cells

2000 ◽  
Vol 14 (9) ◽  
pp. 1188-1201 ◽  
Author(s):  
Jay M. Mei ◽  
Norman G. Hord ◽  
Dolores F. Winterstein ◽  
Steven P. Donald ◽  
James M. Phang
Keyword(s):  
Nitric Oxide ◽  
Epithelial Cells ◽  
Colonic Epithelial Cells ◽  
Prostaglandin Endoperoxide ◽  
Endoperoxide H Synthase
Sign in / Sign up

Export Citation Format

Share Document