Conference proceeding
Evidence for Two Separate Receptors Mediating The Stimulation of Platelet Adenylate Cyclase By Prostaglandin I2 (PGI2), PGD2 and PGE1
Thrombosis and Haemostasis, Vol.42(1)
VIIth International Congress on Thrombosis and Haemostasis - London - 1979-07-15
07/1979
DOI: 10.1055/s-0038-1665817
Abstract
Prostacyclin (PGI
2
), and prostaglandins D
2
and E
1
, all inhibit aggregation of human platelets by stimulating adenylate cyclase. in platelets prelabelled with
l4
C adenine, PGI
2
has a higher intrinsic activity than either PGD
2
or PGE
1
, as well as a higher apparent affinity. PGE
1
but not PGD
2
, inhibits the action of high concentrations of PGI
2
, both when added simultaneously with PGI
2
and when added 3 min later. in the latter case the slow spontaneous fall in intracellular cyclic AMP is accelerated by PGE. but not by PGD
2
. PGF
1α
, at concentrations up to 100 μM neither stimulated the cyclase 1 by itself, nor did it inhibit the effects of PGI
2
, PGE
1
, or PGD
2
. PGF
2α
, which did cause a small increase in cyclic AMP, inhibited PGD
2
strongly, PGE
1
not at all, and PGI
2
slightly at high concentrations. N0164, an inhibitor of aggregation induced by bis-enoic prostaglandins, inhibited cyclase stimulation by PGD
2
but not by PGE
1
, PGE
2
, PGD
1
or PGI
2
, though it reduced PGI
2
-induced inhibition of platelet aggregation. Preaddition of PGE1, but not of PGI
2
or PGD
2
, at submaximal concentrations, inhibited subsequent response to high dose PGI
2
. The results suggest that PGE
1
and PGD
2
probably act on the same enzyme, but through a different receptor. PGE
1
acts as a partial agonist for the receptor for PGI
2
, but in addition causes a tachyphylaxis not seen with PGI
2
or with PGD
2
.
Details
- Title: Subtitle
- Evidence for Two Separate Receptors Mediating The Stimulation of Platelet Adenylate Cyclase By Prostaglandin I2 (PGI2), PGD2 and PGE1
- Creators
- D. C. B. Mils - Temple UniversityD. E. Macfarlane - Temple University
- Resource Type
- Conference proceeding
- Publication Details
- Thrombosis and Haemostasis, Vol.42(1)
- Conference
- VIIth International Congress on Thrombosis and Haemostasis - London - 1979-07-15
- Publisher
- Schattauer GmbH
- DOI
- 10.1055/s-0038-1665817
- ISSN
- 0340-6245
- eISSN
- 2567-689X
- Language
- English
- Date published
- 07/1979
- Academic Unit
- Hematology, Oncology, and Blood & Marrow Transplantation; Internal Medicine
- Record Identifier
- 9984359925502771
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