OBJECTIVE: • To investigate the effect of sensory neurone-specific receptors (SNSRs) activation on the micturition reflex in rats. MATERIALS AND METHODS: • Continuous cystometrograms (CMGs, 0.04 mL/min) were performed in female Sprague-Dawley rats under urethane anaesthesia. • After stable micturition cycles were established, a selective rat SNSR1 agonist, bovine adrenal medulla 8-22 (BAM8-22), was administered intravenously (i.v.) or intrathecally (i.t.) in normal rats or rats pretreated with capsaicin 4 days before the experiments. • Micturition variables were recorded and compared before and after drug administration. RESULTS: • Administration (i.v.) of BAM8-22 (3-100 µg/kg) significantly increased intercontraction intervals in a dose-dependent fashion, but did not affect residual urine or baseline pressure at any doses tested. • Administration (i.t.) of BAM8-22 (0.01-0.3 µg) also increased intercontraction intervals in a dose-dependent fashion, but did not affect residual urine or baseline pressure at any doses tested. • These inhibitory effects of i.v. (30 µg/kg) or i.t. (0.3 µg) administration of BAM8-22 still occurred after capsaicin pretreatment. CONCLUSIONS: • These results indicate that in urethane-anaesthetized rats activation of SNSRs can inhibit the micturition reflex via pathways independent of capsaicin-sensitive C-fibres. • Thus SNSRs could be a potential target for the treatment of bladder dysfunction, e.g. overactive bladder.
OBJECTIVE: • To investigate the effect of sensory neurone-specific receptors (SNSRs) activation on the micturition reflex in rats. MATERIALS AND METHODS: • Continuous cystometrograms (CMGs, 0.04 mL/min) were performed in female Sprague-Dawley rats under urethane anaesthesia. • After stable micturition cycles were established, a selective ratSNSR1 agonist, bovine adrenal medulla 8-22 (BAM8-22), was administered intravenously (i.v.) or intrathecally (i.t.) in normal rats or rats pretreated with capsaicin 4 days before the experiments. • Micturition variables were recorded and compared before and after drug administration. RESULTS: • Administration (i.v.) of BAM8-22 (3-100 µg/kg) significantly increased intercontraction intervals in a dose-dependent fashion, but did not affect residual urine or baseline pressure at any doses tested. • Administration (i.t.) of BAM8-22 (0.01-0.3 µg) also increased intercontraction intervals in a dose-dependent fashion, but did not affect residual urine or baseline pressure at any doses tested. • These inhibitory effects of i.v. (30 µg/kg) or i.t. (0.3 µg) administration of BAM8-22 still occurred after capsaicin pretreatment. CONCLUSIONS: • These results indicate that in urethane-anaesthetized rats activation of SNSRs can inhibit the micturition reflex via pathways independent of capsaicin-sensitive C-fibres. • Thus SNSRs could be a potential target for the treatment of bladder dysfunction, e.g. overactive bladder.
Authors: Sang-Kyou Han; Xinzhong Dong; Jong-Ik Hwang; Mark J Zylka; David J Anderson; Melvin I Simon Journal: Proc Natl Acad Sci U S A Date: 2002-10-23 Impact factor: 11.205
Authors: Paola M C Lembo; Eric Grazzini; Thierry Groblewski; Dajan O'Donnell; Marie-Odile Roy; Ji Zhang; Cyrla Hoffert; Jack Cao; Ralf Schmidt; Manon Pelletier; Maryse Labarre; Mylene Gosselin; Yves Fortin; Denis Banville; S H Shen; Peter Ström; Kemal Payza; Andy Dray; Philippe Walker; Sultan Ahmad Journal: Nat Neurosci Date: 2002-03 Impact factor: 24.884
Authors: Eric Grazzini; Carole Puma; Marie-Odile Roy; Xiao Hong Yu; Dajan O'Donnell; Ralf Schmidt; Sophie Dautrey; Julie Ducharme; Martin Perkins; Rosemarie Panetta; Jennifer M A Laird; Sultan Ahmad; Paola M C Lembo Journal: Proc Natl Acad Sci U S A Date: 2004-04-26 Impact factor: 11.205