Increased plasma norepinephrine concentration in cats with interstitial cystitis.
OBJECTIVE
Interstitial cystitis is a chronic urological syndrome affecting humans and domestic animals, including cats (feline interstitial cystitis). The symptoms of interstitial cystitis seem to be exacerbated by stress, suggesting involvement of the sympathetic nervous system and/or hypothalamic-pituitary-adrenal axis. Others have described sympathetic nervous system abnormalities in patients with interstitial cystitis but to our knowledge no data on plasma catecholamine concentrations or hypothalamic-pituitary-adrenal axis function in such patients have been reported. To evaluate the role of these systems in cats with feline interstitial cystitis we simultaneously measured baseline plasma concentrations of catecholamines and their metabolites to assess sympathetic activity, and the response of plasma adenocorticotropic hormone and cortisol concentrations to the infusion of corticotropin-releasing factor.


METHODS
Eight healthy cats and 8 with feline interstitial cystitis were anesthetized and a catheter was placed in the external jugular vein. Four hours after recovery samples were obtained for high performance liquid chromatography analysis of plasma norepinephrine, dihydroxyphenylglycol, epinephrine, dihydroxyphenylalanine, dopamine and dihydroxyphenylacetic acid. In 4 cats per group 1 microg. ovine corticotropin-releasing factor per kg. body weight was infused and blood samples were collected at intervals for 120 minutes for determining adenocorticotropic hormone and cortisol.


RESULTS
Significant increases in plasma norepinephrine and dihydroxyphenylglycol as well as a trend toward increased epinephrine were found, whereas no effect on dihydroxyphenylalanine, dopamine, dihydroxyphenylacetic acid, adenocorticotropic hormone or cortisol was identified in cats with feline interstitial cystitis.


CONCLUSIONS
These results support and extend previous studies identifying an increase in sympathetic activity in cats with feline interstitial cystitis.
Buffington
C A
CA
Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Ohio State University, Columbus, Ohio, USA.
Pacak
K
K
D000818:Animals; D002371:Cat Diseases / Q000097:blood*; D002415:Cats; D018856:Cystitis, Interstitial / Q000097:blood* / Q000503:physiopathology / Q000662:veterinary*; D005260:Female; D007030:Hypothalamo-Hypophyseal System / Q000503:physiopathology*; D008297:Male; D009638:Norepinephrine / Q000097:blood*; D010913:Pituitary-Adrenal System / Q000503:physiopathology*
D009638:Norepinephrine