Plasma and bronchoalveolar fluid concentrations of nitric oxide and localization of nitric oxide synthesis in the lungs of horses with summer pastureassociated obstructive pulmonary disease

Lais R. R. Costa Equine Health Studies Program, Departments of Veterinary Clinical Sciences and Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803.

Search for other papers by Lais R. R. Costa in
Current site
Google Scholar
PubMed
Close
 MV, MS
,
Thomas L. Seahorn Equine Health Studies Program, Departments of Veterinary Clinical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803.
Present address Haggyard-Davidson McGee Associates, 4250 Iron Works Pike, Lexington, KY 40511.

Search for other papers by Thomas L. Seahorn in
Current site
Google Scholar
PubMed
Close
 DVM, MS
,
Rustin M. Moore Equine Health Studies Program, Departments of Veterinary Clinical Sciences and Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803.

Search for other papers by Rustin M. Moore in
Current site
Google Scholar
PubMed
Close
 DVM, PhD
,
Julian L. Oliver Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803.

Search for other papers by Julian L. Oliver in
Current site
Google Scholar
PubMed
Close
 DVM, PhD
, and
Giselle L. Hosgood Equine Health Studies Program, Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803.

Search for other papers by Giselle L. Hosgood in
Current site
Google Scholar
PubMed
Close
 BVSc, MS

Abstract

Objective—To determine concentrations of nitric oxide (NO) in plasma and bronchoalveolar lavage fluid (BALF) and localize nitric oxide synthesis in the lungs of horses with summer pasture-associated obstructive pulmonary disease (SPAOPD).

Animals—7 adult horses with SPAOPD and 6 clinically normal adult horses.

Procedure—Severity of SPAOPD was determined by use of clinical scores, change in intrapleural pressure (ΔPpl) during tidal breathing, cytologic analysis of BALF, and histologic evaluation of lung specimens obtained during necropsy. Nitric oxide concentrations in plasma, BALF, and epithelial lining fluid (ELF) were determined by use of a chemiluminescent method. Inducible nitric oxide synthase (iNOS) and nitrotyrosine (NT) were localized in formalin-fixed lung specimens by use of immunohistochemical staining, and nicotinamide adenine dinucleotide phosphate diaphorase (NADPHd) activity was localized in cryopreserved specimens by use of histochemical staining.

Results—Plasma concentration of NO in affected horses was slightly but not significantly greater than concentration in nonaffected horses. Nitric oxide concentrations in BALF or ELF did not differ between groups. Immunoreactivity of iNOS in bronchial epithelial cells of 3 of 5 lung lobes was greater in horses with SPAOPD, compared with nonaffected horses. However, staining for NT and NADPHd activity did not differ between groups.

Conclusions and Clinical Relevance—Expression of iNOS was greater in bronchial epithelial cells of horses with SPAOPD, compared with nonaffected horses, suggesting that NO may play a role in amplifying the inflammatory process in the airways of horses with this disease. (Am J Vet Res 2001;62:1381–1386)

Abstract

Objective—To determine concentrations of nitric oxide (NO) in plasma and bronchoalveolar lavage fluid (BALF) and localize nitric oxide synthesis in the lungs of horses with summer pasture-associated obstructive pulmonary disease (SPAOPD).

Animals—7 adult horses with SPAOPD and 6 clinically normal adult horses.

Procedure—Severity of SPAOPD was determined by use of clinical scores, change in intrapleural pressure (ΔPpl) during tidal breathing, cytologic analysis of BALF, and histologic evaluation of lung specimens obtained during necropsy. Nitric oxide concentrations in plasma, BALF, and epithelial lining fluid (ELF) were determined by use of a chemiluminescent method. Inducible nitric oxide synthase (iNOS) and nitrotyrosine (NT) were localized in formalin-fixed lung specimens by use of immunohistochemical staining, and nicotinamide adenine dinucleotide phosphate diaphorase (NADPHd) activity was localized in cryopreserved specimens by use of histochemical staining.

Results—Plasma concentration of NO in affected horses was slightly but not significantly greater than concentration in nonaffected horses. Nitric oxide concentrations in BALF or ELF did not differ between groups. Immunoreactivity of iNOS in bronchial epithelial cells of 3 of 5 lung lobes was greater in horses with SPAOPD, compared with nonaffected horses. However, staining for NT and NADPHd activity did not differ between groups.

Conclusions and Clinical Relevance—Expression of iNOS was greater in bronchial epithelial cells of horses with SPAOPD, compared with nonaffected horses, suggesting that NO may play a role in amplifying the inflammatory process in the airways of horses with this disease. (Am J Vet Res 2001;62:1381–1386)

All Time Past Year Past 30 Days
Abstract Views 23 0 0
Full Text Views 2060 1857 111
PDF Downloads 92 56 6
Advertisement