# BIOCHEMISTRY OF MAST CELL MEDIATOR RELEASE

> **NIH NIH R01** · UT SOUTHWESTERN MEDICAL CENTER · 1987 · $228,164

## Abstract

Preformed and newly formed mediators released from mast cells play a
central role in protective or pathologic immediate hypersensitivity
reactions.  Mast cell mediator release also appears to contribute to some
complement-mediated reactions, to the expression or regulation of
lymphocyte-mediated reactions, to some forms of nonspecific inflammation,
and to some physiologic responses.  The long term objectives of this
proposal are to resolve the biochemical basis of mast cell membrane fusion
- the mechanism of preformed mediators release; and the release of
arachidonic acid - the precursor of several newly formed mediators.  Recent
experiments in this and other laboratories have provided biologic
precedents and direct evidence in rat mast cells that alterations in the
metabolism of sn-1,2-diacylglycerol (DAG) and of phosphatidic acid (PA) may
play pivotal roles in mast cell mediator release.  The specific aims of
this proposal are:  1.) to examine the origins and fates of DAG in
stimulated rat mast cells with particular emphasis on phospholipase C,
phosphatidate phosphohydrolase, DAG kinase and DAG-lipase; 2.) to measure
the levels, origins and fates of other fusogenic lipids in stimulated rat
mast cells with emphasis on DAG, sn-1 or 2-monoacylglycerol and
lysophospholipids; 3.) to examine the origins and fate of newly formed P A
in stimulated mast cells; 4.) to determine the reactions that make
arachidonic acid (AA) available for the synthesis of newly formed mediators
in stimulated mast cells; 5.) to probe the intracellular systems that
regulate these reactions; and 6.) to determine whether or not rat mast
cells express protein kinase activity that is activated by DAG ("protein
kinase C") and if present to characterize the activity in detail.
Identification and characterization of the reactions that lead to membrane
fusion and AA availability in mast cells are fundamental to an
understanding of Ige-mediated reactions at the molecular level.  Improved
knowledge of the mechanisms of mediator release might permit the
development of new approaches to purposeful regulation that in turn
eventually might be applied to improve the management of human allergic or
other inflammatory disorders.

## Key facts

- **NIH application ID:** 3129230
- **Project number:** 5R01AI019801-05
- **Recipient organization:** UT SOUTHWESTERN MEDICAL CENTER
- **SAM.gov UEI:** YZJ6DKPM4W63
- **Principal Investigator:** TIMOTHY J SULLIVAN
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1987
- **Award amount:** $228,164
- **Award type:** 5
- **Project period:** 1983-04-01 → 1988-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3129230

## Citation

> US National Institutes of Health, RePORTER application 3129230, BIOCHEMISTRY OF MAST CELL MEDIATOR RELEASE (5R01AI019801-05). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3129230. Licensed CC0.

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