Abstract
1 The frequency and selectivity of individual variations of prostanoid agonist responses in aortic strips from a population of male rabbits was studied. Three levels of responsiveness to the thromboxane mimetic U46619 occurred: responders (R), intermediate responders (IR), and non-responders (NR). R could be subdivided into R1 and R2 based on an enhanced potency of prostaglandin F2 alpha (PGF2 alpha) in R2. In the total population (n = 92), the phenotype frequency was: R, 69%; IR, 11%; and NR, 20%. In a subgroup of this population in which R1 and R2 phenotypes were determined (n = 63), the phenotype frequency was: R1, 54%; R2, 19%; IR, 6%; and NR, 21%. 2 The four rabbit aorta phenotypes, R1, R2, IR, and NR, were characterized with respect to the rank orders of prostanoid agonist potency, agonist intrinsic activities, and the effects of the thromboxane receptor antagonist SQ29548. The rank order of prostanoid agonist potency was U46619 greater than PGF2 alpha greater than PGE2 in R1 and R2, and PGF2 alpha greater than or equal to PGE2 greater than U46619 in IR and NR. For each prostanoid agonist, the intrinsic activity was highest in R (R1 congruent to R2), intermediate in IR, and lowest in NR. In R1, SQ29548 inhibited all prostanoid agonist responses equally. The contractile effects of PGF2 alpha and PGE2 were partially resistant to inhibition by SQ29548 in R2. Prostanoid agonist responses were not inhibited by SQ29548 in IR. 3 The potency of histamine was equivalent in R1, R2, IR, and NR. 4 It is concluded that there are individual variations in the functional expression of thromboxane receptor sensitivity, i.e., prostanoid agonist responses inhibited by SQ29548. Also, there are individual variations in the functional expression of the sensitivity of a non-thromboxane receptor or receptors, i.e., prostanoid agonist responses not inhibited by SQ29548. It has been proposed by others that prostanoid receptors be termed P-receptors and that the prostanoid agonist to which they are most sensitive be indicated by a preceding letter, e.g., TP- for thromboxane receptor and FP- for PGF2 alpha-selective receptor. Accordingly, we proposed a working hypothesis that suggests the four phenotypes could result from the independent regulation of the functional expression of TP- and FP-receptor subtypes with (a) R2 containing both the TP- and FP-receptor subtypes in a fully functional state; (b) R1 containing only the functional TP-receptor; (c) IR containing only the functional FP-receptor; and (d) NR containing only a low efficacy FP-receptor system.(ABSTRACT TRUNCATED AT 400 WORDS)
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Selected References
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- Altura B. M., Altura B. T. Heterogeneity of drug receptors in different segments of rabbit thoracic aorta. Eur J Pharmacol. 1970 Sep 1;12(1):44–52. doi: 10.1016/0014-2999(70)90027-0. [DOI] [PubMed] [Google Scholar]
- Apperley G. H., Coleman R. A., Kennedy I., Levy G. P. The cat isolated trachea, a useful preparation for the study of the smooth muscle relaxant action of prostaglandins [proceedings]. Br J Pharmacol. 1979 Nov;67(3):412P–413P. [PMC free article] [PubMed] [Google Scholar]
- Best L. C., McGuire M. B., Martin T. J., Preston F. E., Russell R. G. Effects of epoxymethano analogues of prostaglandin endoperoxides on aggregation, on release of 5-hydroxytryptamine and on the metabolism of 3',5'-cyclic AMP and cyclic GMP in human platelets. Biochim Biophys Acta. 1979 Mar 22;583(3):344–351. doi: 10.1016/0304-4165(79)90458-6. [DOI] [PubMed] [Google Scholar]
- Bunting S., Gryglewski R., Moncada S., Vane J. R. Arterial walls generate from prostaglandin endoperoxides a substance (prostaglandin X) which relaxes strips of mesenteric and coeliac ateries and inhibits platelet aggregation. Prostaglandins. 1976 Dec;12(6):897–913. doi: 10.1016/0090-6980(76)90125-8. [DOI] [PubMed] [Google Scholar]
- Bunting S., Moncada S., Vane J. R. The effects of prostagladin endoperoxides and thromboxane A2 on strips of rabbit coeliac artery and certain other smooth muscle preparations [proceedings]. Br J Pharmacol. 1976 Jul;57(3):462P–463P. [PMC free article] [PubMed] [Google Scholar]
- Burch R. M., Mais D. E., Saussy D. L., Jr, Halushka P. V. Solubilization of a thromboxane A2/prostaglandin H2 antagonist binding site from human platelets. Proc Natl Acad Sci U S A. 1985 Nov;82(21):7434–7438. doi: 10.1073/pnas.82.21.7434. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Coleman R. A., Humphrey P. P., Kennedy I., Levy G. P., Lumley P. Comparison of the actions of U-46619, a prostaglandin H2-analogue, with those of prostaglandin H2 and thromboxane A2 on some isolated smooth muscle preparations. Br J Pharmacol. 1981 Jul;73(3):773–778. doi: 10.1111/j.1476-5381.1981.tb16814.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Coleman R. A., Kennedy I. Characterisation of the prostanoid receptors mediating contraction of guinea-pig isolated trachea. Prostaglandins. 1985 Mar;29(3):363–375. doi: 10.1016/0090-6980(85)90096-6. [DOI] [PubMed] [Google Scholar]
- Cunard C. M., Maddox Y. T., Ramwell P. W. Endothelium-dependent gender differences in the response of the rat pulmonary artery to the thromboxane mimic (U46619). J Pharmacol Exp Ther. 1986 Apr;237(1):82–85. [PubMed] [Google Scholar]
- Darius H., Smith J. B., Lefer A. M. Beneficial effects of a new potent and specific thromboxane receptor antagonist (SQ-29,548) in vitro and in vivo. J Pharmacol Exp Ther. 1985 Nov;235(2):274–281. [PubMed] [Google Scholar]
- Dong Y. J., Jones R. L., Wilson N. H. Prostaglandin E receptor subtypes in smooth muscle: agonist activities of stable prostacyclin analogues. Br J Pharmacol. 1986 Jan;87(1):97–107. doi: 10.1111/j.1476-5381.1986.tb10161.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ercan Z. S., Türker R. K. The relaxing activity of iloprost and prostaglandin E2 in the isolated various smooth muscle strips of the rabbit. Pharmacology. 1985;31(2):61–66. doi: 10.1159/000138099. [DOI] [PubMed] [Google Scholar]
- FURCHGOTT R. F., BHADRAKOM S. Reactions of strips of rabbit aorta to epinephrine, isopropylarterenol, sodium nitrite and other drugs. J Pharmacol Exp Ther. 1953 Jun;108(2):129–143. [PubMed] [Google Scholar]
- Furchgott R. F., Zawadzki J. V. The obligatory role of endothelial cells in the relaxation of arterial smooth muscle by acetylcholine. Nature. 1980 Nov 27;288(5789):373–376. doi: 10.1038/288373a0. [DOI] [PubMed] [Google Scholar]
- Förstermann U., Hertting G., Neufang B. The importance of endogenous prostaglandins other than prostacyclin, for the modulation of contractility of some rabbit blood vessels. Br J Pharmacol. 1984 Apr;81(4):623–630. doi: 10.1111/j.1476-5381.1984.tb16127.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gryglewski R. J., Bunting S., Moncada S., Flower R. J., Vane J. R. Arterial walls are protected against deposition of platelet thrombi by a substance (prostaglandin X) which they make from prostaglandin endoperoxides. Prostaglandins. 1976 Nov;12(5):685–713. doi: 10.1016/0090-6980(76)90047-2. [DOI] [PubMed] [Google Scholar]
- Hamberg M., Svensson J., Samuelsson B. Prostaglandin endoperoxides. A new concept concerning the mode of action and release of prostaglandins. Proc Natl Acad Sci U S A. 1974 Oct;71(10):3824–3828. doi: 10.1073/pnas.71.10.3824. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hamberg M., Svensson J., Samuelsson B. Thromboxanes: a new group of biologically active compounds derived from prostaglandin endoperoxides. Proc Natl Acad Sci U S A. 1975 Aug;72(8):2994–2998. doi: 10.1073/pnas.72.8.2994. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Jones R. L., Peesapati V., Wilson N. H. Antagonism of the thromboxane-sensitive contractile systems of the rabbit aorta, dog saphenous vein and guinea-pig trachea. Br J Pharmacol. 1982 Jul;76(3):423–438. doi: 10.1111/j.1476-5381.1982.tb09236.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Karanian J. W., Moran F. M., Ramey E. R., Ramwell P. W. Gender differences in prostaglandin receptors of rat aorta. Br J Pharmacol. 1981 Jan;72(1):10–12. doi: 10.1111/j.1476-5381.1981.tb09097.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Karanian J. W., Ramey E. R., Ramwell P. W. Effect of gender on development and diurnal rhythm of prostaglandin receptors in rat aorta. Br J Pharmacol. 1981 Aug;73(4):903–907. doi: 10.1111/j.1476-5381.1981.tb08744.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kennedy I., Coleman R. A., Humphrey P. P., Levy G. P., Lumley P. Studies on the characterisation of prostanoid receptors: a proposed classification. Prostaglandins. 1982 Nov;24(5):667–689. doi: 10.1016/0090-6980(82)90036-3. [DOI] [PubMed] [Google Scholar]
- Needleman P., Moncada S., Bunting S., Vane J. R., Hamberg M., Samuelsson B. Identification of an enzyme in platelet microsomes which generates thromboxane A2 from prostaglandin endoperoxides. Nature. 1976 Jun 17;261(5561):558–560. doi: 10.1038/261558a0. [DOI] [PubMed] [Google Scholar]
- Ogletree M. L., Harris D. N., Greenberg R., Haslanger M. F., Nakane M. Pharmacological actions of SQ 29,548, a novel selective thromboxane antagonist. J Pharmacol Exp Ther. 1985 Aug;234(2):435–441. [PubMed] [Google Scholar]
- Piper P. J., Vane J. R. Release of additional factors in anaphylaxis and its antagonism by anti-inflammatory drugs. Nature. 1969 Jul 5;223(5201):29–35. doi: 10.1038/223029a0. [DOI] [PubMed] [Google Scholar]
- Svensson J., Hamberg M., Samuelsson B. Prostaglandin endoperoxides IX. Characterization of rabbit aorta contracting substance (RCS) from guinea pig lung and human platelets. Acta Physiol Scand. 1975 Jun;94(2):222–228. doi: 10.1111/j.1748-1716.1975.tb05881.x. [DOI] [PubMed] [Google Scholar]
- VAN ROSSUM J. M. Cumulative dose-response curves. II. Technique for the making of dose-response curves in isolated organs and the evaluation of drug parameters. Arch Int Pharmacodyn Ther. 1963;143:299–330. [PubMed] [Google Scholar]
- Vane J. R. Nobel lecture, 8th December 1982. Adventures and excursions in bioassay: the stepping stones to prostacyclin. Br J Pharmacol. 1983 Aug;79(4):821–838. doi: 10.1111/j.1476-5381.1983.tb10020.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
