Skip to main content
PMC home page
British Journal of Pharmacology logoLink to British Journal of Pharmacology
. 1970 Jul;39(3):556–563. doi: 10.1111/j.1476-5381.1970.tb10363.x

Antagonism of some smooth muscle actions of prostaglandins by polyphloretin phosphate

K E Eakins, S M M Karim, J D Miller
PMCID: PMC1702621  PMID: 4320286

Abstract

1. The antagonism of the smooth muscle stimulating actions of PGF2a and PGE2 by polyphloretin phosphate (PPP) was studied on several isolated smooth muscle preparations and on the blood pressure of the anaesthetized rabbit.

2. PPP (2·5-20 μg/ml) reversibly inhibited contractions of the jird colon produced by PGE2 or PGF2a; PGF2a was more readily antagonized than PGE2.

3. PPP (2·5-30 μg/ml) reversibly antagonized contractions produced by PGE2 and PGF2a on the isolated rabbit jejunum and uterus. In these preparations PPP antagonized PGE2 as readily as PGF2a.

4. It is concluded that PPP is a selective antagonist to the prostaglandins on these tissues, for contractions produced by other agonists, such as acetylcholine, angiotensin, 5-hydroxytryptamine and bradykinin were not reduced by concentrations of PPP which markedly antagonized responses to the prostaglandins.

5. Intravenous injections of PPP (25-200 mg/kg) resulted in a variable antagonism to the fall in blood pressure produced by intravenous injections of PGF2a in the anaesthetized rabbit; vasodepressor responses produced by PGE2 and acetylcholine were not antagonized.

6. The mechanism of this antagonism by PPP is not clear and must await further investigation.

Full text

PDF
556

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. AMBACHE N., KAVANAGH L., WHITING J. EFFECT OF MECHANICAL STIMULATION ON RABBITS' EYES: RELEASE OF ACTIVE SUBSTANCE IN ANTERIOR CHAMBER PERFUSATES. J Physiol. 1965 Feb;176:378–408. doi: 10.1113/jphysiol.1965.sp007557. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Ambache N., Brummer H. C. A simple chemical procedure for distinguishing E from F prostaglandins, with application to tissue extracts. Br J Pharmacol Chemother. 1968 May;33(1):162–170. [PubMed] [Google Scholar]
  3. Beitch B. R., Eakins K. E. The effects of prostaglandins on the intraocular pressure of the rabbit. Br J Pharmacol. 1969 Sep;37(1):158–167. doi: 10.1111/j.1476-5381.1969.tb09533.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Cole D. F. PREVENTION OF EXPERIMENTAL OCULAR HYPERTENSION WITH POLYPHLORETIN PHOSPHATE. Br J Ophthalmol. 1961 Jul;45(7):482–489. doi: 10.1136/bjo.45.7.482. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. FRIES B. The edema-inhibiting action of polyphloretin phosphate (PPP) in some types of capillary damage. An experimental investigation. Acta Chir Scand. 1960 May 25;119:1–7. [PubMed] [Google Scholar]
  6. Fried J., Santhanakrishnan T. S., Himizu J., Lin C. H., Ford S. H., Rubin B., Grigas E. O. Prostaglandin antagonists: synthesis and smooth muscle activity. Nature. 1969 Jul 12;223(5202):208–210. doi: 10.1038/223208a0. [DOI] [PubMed] [Google Scholar]
  7. Sanner J. H. Antagonism of prostaglandin E2 by 1-acetyl-2-(8-chloro-10,11-dihydrodibenz (b,f) (1,4) oxazepine-10-carbonyl) hydrazine (SC-19220). Arch Int Pharmacodyn Ther. 1969 Jul;180(1):46–56. [PubMed] [Google Scholar]

Articles from British Journal of Pharmacology are provided here courtesy of The British Pharmacological Society

RESOURCES