Effects of theophylline on tracheal mucociliary clearance rates in healthy cats.
OBJECTIVE
To determine tracheal mucociliary clearance rate (TMCCR) by use of a standard protocol in healthy anesthetized cats and to determine the effect of theophylline on TMCCR in healthy anesthetized cats.


METHODS
6 healthy cats.


METHODS
Cats were anesthetized with propofol, and a droplet of the radiopharmaceutical technetium Tc 99m macroaggregated albumin was placed endoscopically at the carina. Dynamic acquisition scintigraphic imaging was performed, using the larynx as the end point. The TMCCR was determined by measuring the distance the droplet traveled by frame rate. Each cat was imaged 6 times as follows: 3 times following placebo administration and 3 times following the administration of sustained release theophylline (25 mg/kg, PO). Serum theophylline concentrations were assessed during imaging to ensure therapeutic concentrations.


RESULTS
The TMCCR in healthy adult cats anesthetized with propofol was 22.2 +/- 2.8 mm/min. Tracheal mucociliary clearance rate in cats receiving theophylline was 21.8 +/- 3.5 mm/min. Theophylline administration did not significantly alterTMCCR.


CONCLUSIONS
Theophylline has been shown to increase TMCCR in humans and dogs. In our study, we determined TMCCR in healthy anesthetized cats and found that it was not accelerated by the administration of theophylline.
Dunn
Marilyn E
ME
Department of Veterinary Internal Medicine, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada.
Taylor
Susan M
SM
Shmon
Cindy L
CL
Wilkinson
Alex A
AA
Matte
Gilbert G
GG
Dudzic
Edyta M
EM
Cantwell
Shauna
S
Semple
Hugh
H
D000818:Animals; D001993:Bronchodilator Agents / Q000494:pharmacology*; D002415:Cats; D002923:Cilia / Q000187:drug effects; D004848:Epithelium / Q000187:drug effects; D006262:Health; D009079:Mucociliary Clearance / Q000187:drug effects*; D009093:Mucus / Q000378:metabolism; D019275:Radiopharmaceuticals; D013668:Technetium Tc 99m Aggregated Albumin; D013806:Theophylline / Q000494:pharmacology*; D014132:Trachea / Q000166:cytology / Q000187:drug effects*
D001993:Bronchodilator Agents; D019275:Radiopharmaceuticals; D013668:Technetium Tc 99m Aggregated Albumin; D013806:Theophylline