Length-tension relationship of urinary bladder strips from streptozotocin-diabetic rats.
Length-tension relationship of urinary bladder strips from streptozotocin-diabetic rats.
复制标题
链脲佐菌素糖尿病大鼠膀胱试纸的长度-张力关系。
作者：
Longhurst,PA;Kang,J;Wein,AJ;Levin,RM
链脲佐菌素诱导的糖尿病或饮用5%蔗糖代替饮用水会导致大鼠膀胱容量和质量增加。使用从对照组、糖尿病大鼠或饮用蔗糖的大鼠分离的膀胱体条，绘制长度-张力曲线，以确定糖尿病和非糖尿病利尿相关的膀胱肥大是否改变了长度-张力关系。此外，我们使用三种不同的表达方法对数据进行了比较：(1)发展的绝对克张力；(2)克张力/100毫克组织；(3)克张力/平方毫米。糖尿病大鼠的横截面积比其他两组大鼠明显增加。三组的长度-被动张力曲线都随着组织长度的增加而增加，达到平台期。没有找到产生主动张力的最佳休止长度。糖尿病和饮用蔗糖的大鼠的条带到达平台期的被动张力比对照组大鼠略大。此外，根据数据呈现方法的不同，糖尿病和饮用蔗糖的大鼠的条带通常比对照组大鼠的条带产生更大的主动张力。这些数据表明，膀胱壁中平滑肌纤维的复杂非线性排列导致了膀胱条产生不寻常的长度-张力曲线(与骨骼肌或血管平滑肌相比)。这种关系在神经病变发生之前的早期糖尿病患者的尿囊中将是有益的，在这种情况下，膀胱壁的拉伸将允许在不损害膀胱功能的情况下进行调节。结果表明，比较正常大鼠和糖尿病大鼠的膀胱条功能，应在≥2g的被动张力下进行，以确保产生最大的主动张力。
Streptozotocin-induced diabetes mellitus or the consumption of 5 % sucrose in place of drinking water cause an increase in rat urinary bladder capacity and mass. Length-tension curves were generated using bladder body strips isolated from control, diabetic, or sucrose-drinking rats to determine whether the length-tension relationship was altered by the bladder hypertrophy associated with diabetic and nondiabetic diuresis. In addition, we compared the data using three different methods of expression: (1) absolute grams tension developed; (2) grams tension/100 mg tissue, and (3) grams tension/mm2. The cross-sectional area of strips from diabetic rats was increased compared to the other two groups. The length-passive tension curves for all three groups increased with increasing tissue length to a plateau. No optimal resting length for generation of active tension was found. Strips from diabetic and sucrose-drinking rats reached the plateau at a slightly larger passive tension than did strips from control rats. In addition, strips from diabetic and sucrose-drinking rats generally developed a greater active tension than did strips from control rats depending on the method of data presentation used. The data suggest that the complex nonlinear arrangement of smooth muscle fibers in the bladder wall results in the unusual length-tension curves generated by urinary bladder strips (as compared to skeletal or vascular smooth muscle). This relationship would be of benefit in the urinary bladders of early-stage diabetic patients before neuropathy development, where the stretching of the bladder wall would allow accommodation without any compromise of bladder function. The data indicate that comparisons of bladder strip function from control and diabetic rats should be done at passive tensions of≥2 g to ensure that maximal active tension is generated.