1 The ability of
sodium p-benzyl-4-[1-oxo-2-(4-chlorobenzyl)-3-phenylpropyl]phenyl
phosphonate (N-0164) to antagonize contractions produced by
prostaglandins E2 and F2a on isolated preparations of gerbil, rat and guinea-pig gastrointestinal muscle has been studied. 2
N-0164 was found to be a potent, partially selective
prostaglandin antagonist in these isolated smooth muscle preparations. The blockade produced by
N-0164 in the isolated stomach strip of the rat had some, but not all, the characteristics of a competitive antagonism. 3
N-0164 produced a dose-dependent decrease in tone in the rat stomach strip that was abolished by pretreatment of the preparation with
indomethacin. 4
N-0164 prevented diarrhoea induced by
prostaglandin E2 in mice when given by
intraperitoneal injection but was less effective when given orally. 5
N-0164 inhibited oedema induced with
croton-oil and
pyridine-
ether in the mouse ear. 6
N-0164 delayed the onset of
erythema following ultraviolet irradiation of guinea-pig skin only when an equimolar amount of
pralidoxime chloride was added to the vehicle. 7 It is concluded that
N-0164 is a potent, partially selective
prostaglandin antagonist on several isolated smooth msucle preparations.
N-0164 exhibits activity in vivo particularly following local application when problems associated with penetration and distribution are minimized.