Responses of guinea-pig lung parenchymal strips to tracheobronchial lavage fluid from horses affected with summer pasture-associated obstructive pulmonary disease.
The response of parenchymal strips from guinea-pig lungs to tracheobronchial lavage fluid (TBLF) collected from 8 normal horses and from 8 affected with summer pasture-associated obstructive pulmonary disease (SPAOPD) was determined. TBLF was collected during the summer (July) and winter (February) seasons. The serum/TBLF urea nitrogen ratio was used to standardize the mediator concentration in the TBLF. Four strips were used from each guinea-pig. The first strip did not receive any antagonist and served as the control. The second, third and fourth strips received antagonists of PGE2, LTD4 and PAF, respectively at 10(-6) mol/L for 30 min. The tissues were then precontracted with a dose of histamine (10(-5) mol/L) and their responses to 1 ml of TBLF were determined. The study showed that TBLF obtained in the summer from unaffected horses produced a significantly greater relaxation than that from the affected horses, whereas TBLF obtained in the winter from unaffected or affected horses did not cause a significantly different degree of relaxation. Among the antagonist-treated strips, only those exposed to the PGE2 blocker showed a significant reduction in the relaxation caused by TBLF obtained in the summer from SPAOPD horses. This suggests that PGE2 is an important mediator present in the summer in the TBLF from horses affected with SPAOPD.
Venugopalan
C S
CS
Department of Veterinary Physiology, School of Veterinary Medicine, Louisiana State University, Baton Rouge 70803, USA.
Beadle
R E
RE
Seahorn
T L
TL
Holmes
E P
EP
D000821:Animal Feed / Q000009:adverse effects*; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology; D001992:Bronchoalveolar Lavage Fluid; D015232:Dinoprostone / Q000037:antagonists & inhibitors; D006168:Guinea Pigs; D006632:Histamine / Q000494:pharmacology; D006734:Horse Diseases / Q000097:blood / Q000209:etiology / Q000503:physiopathology*; D006736:Horses; D066298:In Vitro Techniques; D017998:Leukotriene D4 / Q000037:antagonists & inhibitors; D008168:Lung / Q000187:drug effects / Q000502:physiology*; D008173:Lung Diseases, Obstructive / Q000209:etiology / Q000503:physiopathology / Q000662:veterinary*; D009119:Muscle Contraction / Q000187:drug effects; D009126:Muscle Relaxation / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects / Q000502:physiology; D010742:Phospholipid Ethers / Q000494:pharmacology; D010972:Platelet Activating Factor / Q000037:antagonists & inhibitors; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology; D006109:Poaceae / Q000009:adverse effects; D011448:Prostaglandin Antagonists / Q000494:pharmacology; D011804:Quinolines / Q000494:pharmacology; D012016:Reference Values; D012621:Seasons; D014132:Trachea / Q000502:physiology / Q000503:physiopathology; D014966:Xanthenes / Q000494:pharmacology; D044004:Xanthones
D000894:Anti-Inflammatory Agents, Non-Steroidal; D010742:Phospholipid Ethers; D010972:Platelet Activating Factor; D010975:Platelet Aggregation Inhibitors; D011448:Prostaglandin Antagonists; D011804:Quinolines; D014966:Xanthenes; D044004:Xanthones; C049740:alpha-pentyl-3-(2-quinolinylmethoxy)benzenemethanol; C053876:6-isopropoxy-9-oxoxanthene-2-carboxylic acid; D017998:Leukotriene D4; D006632:Histamine; C037913:CV 3988; D015232:Dinoprostone