Kinin receptors in experimental inflammation

Area of Science:

• Pharmacology
• Urology
• Inflammation Research

Background:

• Kinins are peptides that mediate inflammatory responses.
• The rat urinary bladder exhibits contractile responses to kinins.
• Understanding kinin receptor subtypes is crucial for inflammatory pathway research.

Purpose of the Study:

• To investigate the role of kinin receptors (B1 and B2) in rat urinary bladder contraction.
• To determine if B1 receptors are synthesized de novo in response to stimuli.
• To explore the in vivo formation of B1 receptors during inflammation.

Main Methods:

• Isolated rat urinary bladder preparations were used.
• Selective agonists and antagonists for B1 and B2 kinin receptors were employed.
• Cycloheximide was used to assess de novo protein synthesis.
• Inflammation was induced using Triton X-100.

Main Results:

• The rat urinary bladder responds to both B1 and B2 receptor agonists.
• The B1 receptor antagonist Des-Arg10-[Leu9]-kallidin showed similar efficacy as in rabbit aorta.
• Response to the B1 agonist des-Arg9-bradykinin increased with incubation and was blocked by cycloheximide, indicating de novo synthesis.
• Triton X-100-induced inflammation enhanced the response to des-Arg9-BK and led to in vivo B1 receptor formation.

Conclusions:

• The rat urinary bladder possesses both B1 and B2 kinin receptors.
• B1 receptors on the rat urinary bladder are synthesized de novo.
• Inflammatory stimuli promote the in vivo synthesis of B1 receptors.
• De novo synthesis of B1 kinin receptors may contribute to inflammatory processes in the bladder.