Inflammation and enhanced nociceptive responses to bladder distension produced by intravesical zymosan in the rat.
BACKGROUND
Mycotic infections of the bladder produce pain and inflammatory changes. The present study examined the inflammatory and nociceptive effects of the yeast cell wall component, zymosan, when administered into the urinary bladder in order to characterize this form of bladder sensitization.


METHODS
Parametric analyses of the time-course (0-48 hr) and concentration (0-2% solutions) variables associated with intravesical zymosan-induced bladder inflammation were performed in female rats. Plasma extravasation of Evan's Blue dye was used as a measure of tissue inflammation. Cardiovascular and visceromotor responses to urinary bladder distension were used as measures of nociception.


RESULTS
Zymosan-induced bladder inflammation, as indexed by plasma extravasation of Evan's Blue, was significantly greater in rats treated with either 1 or 2% solutions as compared to either 0.1 or 0.5% zymosan solutions. In time-course studies (1-48 hr post-treatment), 1% zymosan-induced inflammation progressively increased with time following administration, was greatest at 24 hr and began to normalize by 48 hr. In the studies of inflammation-induced changes in nociception, arterial blood pressure (ABP) and visceromotor responses to graded distension of the urinary bladder were significantly increased relative to controls 24 hr after zymosan administration.


CONCLUSIONS
These studies provide important time-course and solution concentration parameters for studies of zymosan-induced inflammation of the bladder and suggest utility of this model for the study of bladder-related pain.
Department of Psychology, University of Alabama, Birmingham, AL 35294, USA. arandich@uab.edu
Alan
A
Randich
Tyler
T
Uzzell
Ronda
R
Cannon
Timothy J
TJ
Ness
D000283:Administration, Intravesical; D000818:Animals; D001794:Blood Pressure; D004396:Coloring Agents / Q000493:pharmacokinetics; D003556:Cystitis / Q000139:chemically induced / Q000150:complications / Q000503:physiopathology*; D004576:Electromyography; D005070:Evans Blue / Q000493:pharmacokinetics; D005260:Female; D010146:Pain / Q000209:etiology / Q000503:physiopathology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D001743:Urinary Bladder / Q000737:chemistry / Q000503:physiopathology*; D015054:Zymosan / Q000008:administration & dosage / Q000633:toxicity*
D004396:Coloring Agents; D005070:Evans Blue; D015054:Zymosan