Bradykinin increases intracellular calcium levels in rat testis peritubular cells via the B2 receptor subtype

• Published in: British journal of pharmacology Vol. 138; no. 2; pp. 351 - 358
• Main Authors: Wennemuth, Gunther, Blöcher, Sonja, Schill, Wolf‐Bernhard, Aumüller, Gerhard, Monsees, Thomas K
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.01.2003; Nature Publishing
• Subjects: Animals; Biological and medical sciences; bradykinin; Bradykinin - pharmacology; Calcium - metabolism; Cell receptors; Cell structures and functions; Cells, Cultured; Fundamental and applied biological sciences. Psychology; intracellular calcium; Intracellular Fluid - drug effects; Intracellular Fluid - metabolism; Kinin B2 receptor; Male; male reproduction; Molecular and cellular biology; Neuropeptide receptors; peritubular cells; rat; Rats; Rats, Sprague-Dawley; Receptor, Bradykinin B2; Receptors, Bradykinin - agonists; Receptors, Bradykinin - metabolism; testis; Testis - cytology; Testis - drug effects; Testis - metabolism; Kinin B2 receptor; male reproduction; peritubular cells; Rat; Rodentia; Electrophysiology; bradykinin; Male; testis; Testicle; In vitro; B2 bradykinin receptor; Vertebrata; Reproduction; Mammalia; Calcium ion; Animal; intracellular calcium
• ISSN: 0007-1188; 1476-5381
• DOI: 10.1038/sj.bjp.0705039

RT–PCR and Western blots were used to detect bradykinin B2 receptors in testis and isolated peritubular cells of pre‐pubertal rats. RT–PCR demonstrated expression of a single transcript, whereas Western blots showed up to three specific bands that were in accordance with the described native, glycosylated and dimeric form of B2 receptor proteins, respectively. Fura‐2‐loaded peritubular cells responded with an instantaneous, linear and transient rise in [Ca2+]i after adding bradykinin. Stimulation of cells with bradykinin concentrations between 1 μM and 1 pM showed a dose dependent increase of [Ca2+]i. The calcium response to bradykinin was diminished after stimulation of peritubular cells in calcium‐free buffer. After blocking the SERCA‐pumps by thapsigargin and subsequent stimulation with bradykinin, no rise of [Ca2+]i was appreciated. Multiple stimulation of a single peritubular cell by local perfusion with a brief addition of BK (10 nM) resulted in a fast and immediate response. However, the second and third stimuli had slower rise rates and diminished [Ca2+]i peaks, showing desensitization of the kinin receptor. Addition of the bradykinin B1 receptor agonist [des‐Arg9]‐bradykinin (100 nM) to Fura‐2‐loaded peritubular cells did not change the [Ca2+]i. However, the B2 receptor antagonist HOE 140 (100 nM) strongly inhibited the bradykinin‐induced calcium response. We conclude that the bradykinin‐induced increase in [Ca2+]i, in testicular peritubular cells is mediated by the stimulation of kinin receptors of the B2 subtype. British Journal of Pharmacology (2003) 138, 351–358. doi:10.1038/sj.bjp.0705039