Abstract
The ability of polyphloretin phosphmate (PPP) to block prostaglandin (PG) activity on the gut, tracheobronchial tree and blood pressure was studied in cats anesthetized with Nembutal (36 mg/kg i.p.) and 70% N2O in 02. Carbachol and PGF2α consistently produced an increase in airway pressure, stimulation of intestinal activity and a fall in blood pressure. The effects of PGE2 on intestinal activity and blood pressure were similar to those of PGF2α. However, PGE2 had no effect on normal airway pressure but lowered airway pressure raised by pretreatment with phospholine iodide (0.1 mg/kg i.v.). The initial effect of PPP (200 mg/kg i.v.) was to stimulate intestinal motility and transiently decrease blood pressure. Airway pressure was unchanged or slightly elevated. All the effects of PGF2α were blocked by PPP. In contrast, PPP blocked only the intestinal stimulation of PGE2 but did not antagonize the effect of PGE2 on blood pressure or airway pressure. PPP did not block the actions of carbachol on ileum or blood pressure but did inhibit the increase in airway pressure. PPP given i.p. also blocked the effect of PGF2α on the ileum. These results show PPP 1) to cause stimulation of gastrointestinal activity, 2) to antagonize all responses to PGF2α monitored and 3) to antagonize only the gastrointestinal effects of PGE2. It was concluded that PPP is active, in vivo, as an antagonist of some, but not of all, of the actions of prostaglandins studied.
Footnotes
- Received March 15, 1971.
- Accepted September 17, 1971.
- © 1972, by The Williams & Wilkins Company
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