title: Demonstration of prostaglandin activity in lungs of the rainbow lizard (Agama agama) by bioassay.
abstract: Extracts and perfusate effluents of lungs of the rainbow lizard (Agama agama) were assayed for prostaglandin-like activity. Results of differential bioassay and thin-layer chromatography suggested that the prostanoid was predominantly PGE2-like. The mean PGE2-like content of 10 lizard lung extracts was 2.9 micrograms g-1 wet weight compared with 146 ng g-1 in rat lungs. Mechanical pressure applied to the lung during perfusion through the pulmonary vasculature provoked the release of large quantities of PGE2-like material. This release was blocked by fatty acid cyclooxygenase inhibitors. Compared with guinea-pig and rat lungs, lizard lungs exhibited a markedly low capacity for inactivating PGE2. In view of an apparently high prostaglandin-forming and a low inactivating capacity, we speculate that under certain circumstances, lizard lungs may release vasoactive substances into the circulation.
authors.affiliation: Department of Pharmacology and Therapeutics, College of Medicine, University of Ibadan, Nigeria.
authors.forename: F O
authors.initials: FO
authors.lastname: Ajayi
authors.forename: D T
authors.initials: DT
authors.lastname: Okpako
mesh_terms: D000818:Animals; D002855:Chromatography, Thin Layer; D016861:Cyclooxygenase Inhibitors; D015232:Dinoprostone / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005260:Female; D008116:Lizards; D008168:Lung / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D010477:Perfusion; D011453:Prostaglandins / Q000302:isolation & purification / Q000378:metabolism / Q000502:physiology*; D011651:Pulmonary Artery; D011652:Pulmonary Circulation / Q000187:drug effects
chemical_list: D016861:Cyclooxygenase Inhibitors; D011453:Prostaglandins; D015232:Dinoprostone