Bradykinin increases intracellular calcium levels in rat testis peritubular cells via the B2 receptor subtype.
Br J Pharmacol
; 138(2): 351-8, 2003 Jan.
Article
em En
| MEDLINE
| ID: mdl-12540526
ABSTRACT
1. RT-PCR and Western blots were used to detect bradykinin B(2) 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 B(2) receptor proteins, respectively. 2. Fura-2-loaded peritubular cells responded with an instantaneous, linear and transient rise in [Ca(2+)](i) after adding bradykinin. Stimulation of cells with bradykinin concentrations between 1 micro M and 1 pM showed a dose dependent increase of [Ca(2+)](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 [Ca(2+)](i) was appreciated. 3. 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 [Ca(2+)](i) peaks, showing desensitization of the kinin receptor. 4. Addition of the bradykinin B(1) receptor agonist [des-Arg(9)]-bradykinin (100 nM) to Fura-2-loaded peritubular cells did not change the [Ca(2+)](i). However, the B(2) receptor antagonist HOE 140 (100 nM) strongly inhibited the bradykinin-induced calcium response. 5. We conclude that the bradykinin-induced increase in [Ca(2+)](i), in testicular peritubular cells is mediated by the stimulation of kinin receptors of the B(2) subtype.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Testículo
/
Bradicinina
/
Cálcio
/
Receptores da Bradicinina
/
Líquido Intracelular
Limite:
Animals
Idioma:
En
Revista:
Br J Pharmacol
Ano de publicação:
2003
Tipo de documento:
Article