Length-Tension Relationship of Urinary Bladder Strips from Streptozotocin-Diabetic Rats

Abstract

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.

Diabetic Complications in a New Animal Model (TSOD mouse) of Spontaneous NIDDM with Obesity

“…In mice with severe hind-limb weakness, the characteristic signs of distension of urinary bladder, dilatation of pelvis, denudation and smudge of penis were observed. Similar symptoms of the urinary bladder were also described in Chinese Hamster with diabetes [6] and streptozotocininduced diabetic rats [13,24]. In Chinese Hamster, aberrant myelination was found in the pelvic plexus and urinary bladder [6].…”

Factors underlying the increased sensitivity to field stimulation of urinary bladder strips from streptozotocin‐induced diabetic rats

“…The tissues were connected to Grass force displacement transducers (FT03) and adjusted to 2 g resting tension. Previously it was determined in our laboratory that maximal active tension was generated at 2 g resting tension in all groups (Longhurst et al, 1990a). Responses were recorded on a Grass Model 7E polygraph.…”

Diabetes mellitus and responses of the urinary bladder to acetylcholine: an in vitro study

“…It has been shown that in diabetic animals, contractile responses of the urinary bladder to muscarinic agonists is inconsistent. Some investigators have reported increased responses (Kolta et al, 1985;Latifpour et al, 1088;Kamata et al, 1992;Tong et al, 2002), while others have reported decreased responses (Longhurst and Belis, 1986;Longhurst et al, 1990), or no change in contractile responses (Lincoln et al, 1984;Luheshi and Zar, 1991) of diabetic urinary bladder smooth muscle strip to muscaric agonists.…”