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Privacy Policy. The contraction response was significantly decreased in response to Ach in normal rats more than that in DM rats. Rat bladder smooth muscle was pre-treated with U for 20 min before the experiment.
For ACh-induced contraction, there was only a small change in contraction in both groups compared to the control and these differences were not statistically significant. Rat bladder smooth muscle was pre-treated with chelerythrine for 20 min before the experiment.
In these experiments examining intracellular signaling pathways, modulators of calcium channels, PLC had significantly different effects on bladder smooth muscle contraction responses between normal and DM rats. Rat bladder smooth muscle was pre-treated with udenafil for 15 min before the experiment. For the ACh-induced contraction, the DM rats also had a higher percent contraction than normal rats. Rat bladder smooth muscle was pre-treated with NaHS for 15 min before the experiment. In addition, there were no significant differences between the controls in each group.
Rat bladder smooth muscle was pre-treated with papaverine for 15 min before the experiment. Papaverine had a smooth muscle relaxing effect on ACh-induced contraction in both normal and DM rats. For ACh-induced contraction, the inhibition of contraction was greater in normal rats than in DM rats. Bladder dysfunction is one of the main complications in DM Golbidi and Laher, A decrease in detrusor contractility is a common symptom in bladder dysfunction Bradley, Many causes can influence bladder smooth muscle contraction.
The present study was conducted to investigate which receptor or enzymes affect the contraction of bladder smooth muscle in a rat DM model. In addition, an enhanced adrenoceptor receptor response has been observed in the DM rat bladder Kudlacz et al.
Adenosine A 1 receptors are known to be expressed in the uroepithelium of the bladder Yu et al. DPCPX 8-cyclopentyl-1, 3-dipropylxanthine is a drug that acts as a selective antagonist of the adenosine A 1 receptor Lohse et al.
Adenosine-induced relaxation is primarily thought to occur through P1A1 receptors because an antagonist of the P1A1 receptor DPCPX has been shown to decrease adenosine-induced relaxation in a normal rat bladder Vesela et al. In this study, prazosin had a significantly different effect on contraction between normal and DM rats. Udenafil PDE5 inhibitor , which is used for the erectile dysfunction treatment. It has also been suggested that treatment with vardenafil, another PDE5 inhibitor, increases the bladder smooth muscle contraction.
This effect is thought to be mediated through changes in cGMP that lead to increases in intracellular calcium levels, thus increasing bladder contraction Rybalkin et al. This study also suggests that the cGMP pathway might be involved in the control of relaxation of bladder smooth muscle in DM.
It has been reported that the density of muscarinic receptors in the rat bladder increases during the early stages of DM Tong et al. It has also been reported that M 3 muscarinic receptors cause bladder contraction in a PLC-independent mechanism Sand and Michel, The main pathway for muscarinic stimulation of contraction of bladder smooth muscle involves the activation of PLC, which leads to the generation of inositol-1, 4, 5-trisphosphate IP 3 Andersson and Arner, Many studies have observed alterations in calcium channel sensitivity and calcium concentration in DM rats.
In particular it has been shown that intracellular calcium levels are elevated in animal models of DM Belis et al. Papaverine is an anti-spasmolytic drug that has long been known to have a smooth muscle relaxing effect Ferrari, It has been reported that papaverine relaxes smooth muscle by reducing the activity of cyclic nucleotide PDEs, as well as reducing calcium transport Huddart et al. Our data demonstrated that the percentage decrease in bladder contraction was larger in normal rats treated with papaverine than in DM rats.
NaHS also induces the relaxation of bladder smooth muscle, and it is known that H 2 S synthetic enzymes are expressed in the bladder. However, we found no significant differences in smooth muscle bladder contraction between normal and DM rats following NaHS treatment.
Several studies have investigated the effect of DM on contraction in cardiac muscle and colonic smooth muscle. It has been reported that the cholinergic response and the contractility of colonic smooth muscle were reduced in DM rats.
The contractile response of the proximal colon to carbachol, an acetylcholine receptor agonist, was also found to be significantly weaker in diabetic rats. Kim et al. Another study in DM using female GK rats demonstrated that these rats had a reduced contraction of the left ventricular muscle Iltis et al.
Our study has several limitations. First, only male rats were used. Male rats have organs that do not exist in female rats, such as the penis and the prostate. These male-specific organs may have effects on bladder smooth muscle contraction that we did not take into account. Second, the effect of age was not studied because all of the rats used here were of a similar age 10 weeks.
In this regard, it has been reported that the contractility of rats changes over time Daneshgari et al. Third, a hypercontractile state was also observed in DM rats. There might be various other factors that affect the contraction of bladder smooth muscle. Accordingly, additional experiments will be required to address these limitations. In conclusion, the results of the present study show that the bladder contractility is decreased in DM rats. While atropine has no inhibitory effect in DM rats, the responses to a PLC inhibitor, a calcium channel blocker, and a PDE5 inhibitor were significantly different between normal and DM rats.
Representative traces and tension comparison for ACh-induced contraction of bladder smooth muscle in normal and DM rats. A ACh-induced contraction. The left- and right-hand sides of 1A represent normal and DM rats, respectively.
Changes in contraction following prazosin treatment of bladder smooth muscle from normal or DM rats. ACh-induced contraction. Changes in contraction following verapamil treatment of bladder smooth muscle from normal or DM rats. Changes in contraction following udenafil treatment of bladder smooth muscle from normal or DM rats.
Title Author Keyword Volume Vol. Induction of diabetes STZ is often used in medical research to produce an animal model of hyperglycemia, as well as diabetes. Changes in contraction following atropine treatment of bladder smooth muscle from normal or DM rats. Hyperglycaemia enhances nitric oxide production in diabetes: a study from South Indian patients. Amaral, N, and Okonko, DO Metabolic abnormalities of the heart in type II diabetes.
Andersson, KE, and Arner, A Urinary bladder contraction and relaxation: physiology and pathophysiology. Activation of the nitric oxide-cGMP pathway reduces phasic contractions in neonatal rat bladder strips via protein kinase G. Neurogenic function of the diabetic rat bladder: alteration by calcium channel effectors. Bradley, WE Diagnosis of urinary bladder dysfunction in diabetes mellitus.
M2 and M3 muscarinic receptor activation of urinary bladder contractile signal transduction. Normal rat bladder. Bucheimer, RE, and Linden, J Purinergic regulation of epithelial transport. Time dependent changes in diabetic cystopathy in rats include compensated and decompensated bladder function. Diederichs, W Effects of papaverine on tension and 45Ca-uptake in isolated urinary bladder. Hydrogen sulfide mediates hypoxia-induced relaxation of trout urinary bladder smooth muscle.
J Exp Biol. Ferrari, M Effects of papaverine on smooth muscle and their mechanisms. Golbidi, S, and Laher, I Bladder dysfunction in diabetes mellitus. Inhibition by papaverine of calcium movements and tension in the smooth muscles of rat vas deferens and urinary bladder. Defective myocardial blood flow and altered function of the left ventricle in type 2 diabetic rats: a noninvasive in vivo study using perfusion and cine magnetic resonance imaging.
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