کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5629240 1406406 2016 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Research PaperInfluence of urothelial or suburothelial cholinergic receptors on bladder reflexes in chronic spinal cord injured cats
موضوعات مرتبط
علوم زیستی و بیوفناوری علم عصب شناسی عصب شناسی
پیش نمایش صفحه اول مقاله
Research PaperInfluence of urothelial or suburothelial cholinergic receptors on bladder reflexes in chronic spinal cord injured cats
چکیده انگلیسی

The effects of intravesical administration of a muscarinic receptor agonist (oxotremorine-M, OXO-M) and antagonist (atropine methyl nitrate, AMN) and of a nicotinic receptor agonist (nicotine) and antagonist (hexamethonium, C6) on reflex bladder activity were investigated in conscious female chronic spinal cord injured (SCI) cats using cystometry. OXO-M (50 μM) decreased bladder capacity (BC) for triggering micturition contractions, increased maximal micturition pressure (MMP), increased frequency and area under the curve of pre-micturition contractions (PMC-AUC). Nicotine (250 μM) decreased BC, increased MMP, but did not alter PMC-AUC. The effects of OXO-M on BC and PMC-AUC were suppressed by intravesical administration of AMN (50-100 μM), and the effects of nicotine were blocked by hexamethonium (1 mM). Antagonists infused intravesically alone did not alter reflex bladder activity. However, AMN (0.2 mg/kg, subcutaneously) decreased PMC-AUC. 8-OH-DPAT (0.5 mg/kg, s.c.), a 5-HT1A receptor agonist, suppressed the OXO-M-induced decrease in BC but not the enhancement of PMC-AUC. These results indicate that activation of cholinergic receptors located near the lumenal surface of the bladder modulates two types of reflex bladder activity (i.e., micturition and pre-micturition contractions). The effects may be mediated by activation of receptors on suburothelial afferent nerves or receptors on urothelial cells which release transmitters that can in turn alter afferent excitability. The selective action of nicotine on BC, while OXO-M affects both BC and PMC-AUC, suggests that micturition reflexes and PMCs are activated by different populations of afferent nerves. The selective suppression of the OXO-M effect on BC by 8-OH-DPAT without altering the effect on PMCs supports this hypothesis. The failure of intravesical administration of either AMN or hexamethonium alone to alter bladder activity indicates that cholinergic receptors located near the lumenal surface do not tonically regulate bladder reflex mechanisms in the SCI cat.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Experimental Neurology - Volume 285, Part B, November 2016, Pages 147-158
نویسندگان
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