Rabbit versus rat urinary bladder: effects of in vitro hypoxia.
Rabbit versus rat urinary bladder: effects of in vitro hypoxia.
复制标题
兔子与大鼠膀胱：体外缺氧的影响。
作者：
Whitbeck,C;Barreto,M;Horan,P;Levin,SS;Levin,RM
目的：研究表明膀胱缺氧可能是下尿路功能障碍的病因之一。大鼠和家兔是研究下尿路功能和功能障碍常用的两种实验动物。本研究的目的是直接比较体外低氧对大鼠和家兔膀胱对不同形式刺激的收缩反应的影响。在麻醉动物的同时切除每个膀胱，并切割纵向膀胱条，然后固定在器官浴中。在所有条带上施加2g的张力。结果：大鼠膀胱肌条单位组织质量的收缩力均显著大于兔膀胱肌条对场刺激（FS）、卡巴胆碱（100 μmol/l）、KCl（120 mmol/l）和ATP的收缩力。缺氧（随后复氧）导致膀胱条对所有刺激的收缩反应呈时间依赖性进行性降低。大鼠膀胱对FS和卡巴胆碱的反应比兔膀胱对缺氧的反应更敏感。结论：大鼠膀胱神经源性和胆碱能反应对缺氧的敏感性明显高于兔膀胱，这可能与大鼠膀胱产生更大的收缩力和更高的Ca ~（2+）-ATP酶活性有关。
Purpose:Studies indicate that bladder hypoxia may be an etiological factor for lower urinary tract dysfunction. Rat and rabbit are two species of experimental animals used frequently to study lower urinary tract function and dysfunction. The objective of this study was to compare directly effects of in vitro hypoxia on contractile responses of rat and rabbit urinary bladder to different forms of stimulation.Methods:Sexually mature male New Zealand White rabbits and Sprague-Dawley rats were compared. Each bladder was excised while the animal was anesthetized, and longitudinal bladder strips were cut, then mounted in organ baths. A tension of 2 g was placed on all strips. Effects of 1, 2, 3 and 4 h hypoxia followed by 1 h of reoxygenation on contractile responses of bladder strips to field stimulation (FS), carbachol (100 μmol/l), ATP (1 mmol/l) and KCl (120 mmol/l) were determined.Results:Contractility, per unit tissue mass, of rat bladder strips was significantly greater than that of rabbit bladder strips in response to FS (all frequencies), carbachol, KCl and ATP. Hypoxia (followed by reoxygenation) resulted in time-dependent progressive reduction in contractile responses of bladder strips to all stimuli. Rat bladder was significantly more sensitive to hypoxia than rabbit bladder in response to FS and carbachol. Hypoxia induced similar effects on rat and rabbit bladder responses to ATP and KCl.Conclusion:Rat bladder neurogenic and cholinergic responses are significantly more sensitive to hypoxia than are those of rabbit bladder, which may be due to the rat bladder’s greater contractile force generation and previously reported higher Ca2+-ATPase activity.