The Journal of urology · 2004
Demonstration of bladder selective muscarinic receptor binding by intravesical oxybutynin to treat overactive bladder.
СтатьяПоддержка исследования: вне правительства СШАНазвание и аннотация: Перевод в очереди
Обработка статьи · этапы, ошибки и управление
Загрузка состояния…
Ошибки и ограничения
История · было → стало
Состояние обновляется каждые 5 секунд, пока блок открыт. Процент показывается только там, где известен объём работы. Пауза останавливает продолжение этапа; текущий запрос к источнику может завершиться.
Oki Tomomi, Kimura Ryohei, Saito Motoaki, Miyagawa Ikuo, Yamada Shizuo
Аннотация
PURPOSE: The current study was done to elucidate the in vivo mechanism of action of intravesical instillation of oxybutynin to treat overactive bladder.
MATERIALS AND METHODS: In rats receiving oral and intravesical oxybutynin we measured muscarinic receptors in the bladder and other tissues by radioligand binding assay using [3H]NMS ([N-methyl-3H] scopolamine methyl chloride) with the simultaneous measurement of plasma concentrations of oxybutynin and its active metabolite N-desethyl-oxybutynin. Pilocarpine induced salivary secretion was also measured.
RESULTS: Following oral administration of oxybutynin there was a significant increase in the apparent dissociation constant (Kd) for specific [3H]NMS binding in the bladder, submaxillary gland, heart and colon of rats at 1 and 3 hours with a consistent decrease in the maximal number of binding sites (Bmax) in the submaxillary gland. Furthermore, a marked and prolonged decrease in pilocarpine induced salivary secretion in rats was observed by oral oxybutynin. In contrast, intravesical instillation of oxybutynin produced a significant increase in Kd for specific [3H]NMS binding in the bladder of rats at 0.5 to 4 hours later and also in the submaxillary gland only at 0.5 hours later. The enhancement in Kd was much larger and longer lasting in the bladder than in the submaxillary gland. Moreover, intravesical oxybutynin had little muscarinic receptor binding activity in the heart and colon, and little significant suppression of pilocarpine induced salivation in rats. The plasma concentrations of oxybutynin and N-desethyl-oxybutynin were much higher in rats receiving oxybutynin orally than intravesically.
CONCLUSIONS: Intravesical oxybutynin in rats may cause selective binding of bladder muscarinic receptors via a direct local effect, while oral oxybutynin may exert predominant binding of salivary gland receptors.
MATERIALS AND METHODS: In rats receiving oral and intravesical oxybutynin we measured muscarinic receptors in the bladder and other tissues by radioligand binding assay using [3H]NMS ([N-methyl-3H] scopolamine methyl chloride) with the simultaneous measurement of plasma concentrations of oxybutynin and its active metabolite N-desethyl-oxybutynin. Pilocarpine induced salivary secretion was also measured.
RESULTS: Following oral administration of oxybutynin there was a significant increase in the apparent dissociation constant (Kd) for specific [3H]NMS binding in the bladder, submaxillary gland, heart and colon of rats at 1 and 3 hours with a consistent decrease in the maximal number of binding sites (Bmax) in the submaxillary gland. Furthermore, a marked and prolonged decrease in pilocarpine induced salivary secretion in rats was observed by oral oxybutynin. In contrast, intravesical instillation of oxybutynin produced a significant increase in Kd for specific [3H]NMS binding in the bladder of rats at 0.5 to 4 hours later and also in the submaxillary gland only at 0.5 hours later. The enhancement in Kd was much larger and longer lasting in the bladder than in the submaxillary gland. Moreover, intravesical oxybutynin had little muscarinic receptor binding activity in the heart and colon, and little significant suppression of pilocarpine induced salivation in rats. The plasma concentrations of oxybutynin and N-desethyl-oxybutynin were much higher in rats receiving oxybutynin orally than intravesically.
CONCLUSIONS: Intravesical oxybutynin in rats may cause selective binding of bladder muscarinic receptors via a direct local effect, while oral oxybutynin may exert predominant binding of salivary gland receptors.