Effect of Doxazosin on Autonomic Nervous Control and Urodynamics of Rat Urinary Bladder during Modeled Infravesical Obstruction.

The therapeutic effect of doxazosin (40 µg/kg/day over one month) on urinary bladder was examined in female rats with modeled chronic infravesical obstruction (IVO) produced by graduated mechanical constriction of the proximal urethral segment. In one month, IVO induced a pronounced vesical hypertrophy both in treated and untreated rats that manifested in increased bladder weight and capacity, the latter increment being pronouncedly greater in treated rats. In untreated IVO rats, infusion cystometry revealed elevated basal intravesical pressure of void bladder P0, markedly increased maximal (premicturitional) pressure Pmax, and increased amplitude of spontaneous oscillations of intravesical pressure ΔPdet in filled bladder. Doxazosin produced no significant effect on Pmax rise during IVO, but prevented elevation of P0 and increment of ΔPdet in filled bladder. During gradual filling of urinary bladder in control (intact) rats, the parasympathetic vesical influences increased progressively, while in untreated IVO rats, the adrenergic influences prevailed even at maximal filling of the bladder. In IVO rats, doxazosin prevented the bias of the sympathetic-parasympathetic balance in the filled bladder in favor of sympathetic influences, but did not prevent this bias in a void bladder. It is hypothesized that α-adrenoblockers improve micturition during IVO caused by benign prostatic hyperplasia not only by decreasing the urethral resistance to urine flow due to down-regulation of prostate smooth muscle tone, but also by a direct action of these blockers on detrusor adrenergic receptors and central structures involved in urinary bladder control.

Efficacy of intravesical pentosan polysulfate sodium in cats with obstructive feline idiopathic cystitis.

OBJECTIVES: Obstructive feline idiopathic cystitis is a common emergency in small animal practice. There is evidence for a defective glycosaminoglycan layer in the urinary bladder of affected cats. The aim of this study was to investigate the effect of intravesical pentosan polysulfate sodium (PPS) in cats with obstructive feline idiopathic cystitis in a randomised, placebo-controlled, blinded clinical study. METHODS: Thirty-five cats with obstructive feline idiopathic cystitis were enrolled into the study. On day 0, cats were randomised to receive either 30 mg PPS in saline (18 cats) or saline alone as placebo (17 cats) at the time of indwelling urinary catheter placement and then after 24 and 48 h. The catheter was clamped for 30 mins after administration before connecting it to a sterile urine collection system. The procedure was repeated after 24 and 48 h, and then the indwelling catheter was removed. Treatment success was assessed via the incidence of recurrent urethral obstruction, results of a scoring system for physical examination and daily urinalysis from day 0 to 5. RESULTS: Recurrent urethral obstruction occurred in 3/18 cats of the verum group and 3/17 of the placebo group (P = 1.000). The verum group showed a significantly lower degree of microscopic haematuria between day 5 and day 0 (P ⩽0.05). The placebo group showed a significantly lower degree of dipstick haematuria between day 5 and day 0 (P ⩽0.05). There was no difference in the clinical score between the groups in the investigated time period. CONCLUSIONS AND RELEVANCE: Intravesical instillation of PPS three times within 48 h in the chosen dose had no influence on the incidence of recurrent urethral obstruction and clinical signs in cats with obstructive feline idiopathic cystitis.

Reduction of obstruction related bladder overactivity by the guanylyl cyclase modulators BAY 41-2272 and BAY 60-2770 alone or in combination with a phosphodiesterase type 5 inhibitor.

AIMS: To assess the urodynamic effects of soluble guanylyl cyclase (sGC) stimulator, BAY 41-2272, and activator, BAY 60-2770, (which both are able to induce cGMP synthesis even in the absence of nitric oxide (NO)) alone or in combination with a phosphodiesterase type 5 (PDE5) inhibitor, vardenafil, in a model of partial urethral obstruction (PUO) induced bladder overactivity (BO). METHODS: Fifty-six male Sprague-Dawley rats were used, 31 of them underwent PUO. Fourteen rats were used for Western blots to assess PDE5 and sGC expression. For drug evaluation cystometry without anesthesia was performed three days following bladder catheterization. RESULTS: Obstructed rats showed higher micturition frequency and bladder pressures than non-obstructed animals (Intermicturition Interval, IMI, 2.28 ± 0.55 vs. 3.60 ± 0.60 min (± standard deviation, SD); maximum micturition pressure, MMP, 70.1 ± 8.0 vs. 48.8 ± 7.2 cmH2O; both P < 0.05). In obstructed rats vardenafil, BAY 41-2272, and BAY 60-2770 increased IMI (2.77 ± 1.12, 2.62 ± 0.52, and 3.22 ± 1.04 min; all P < 0.05) and decreased MMP (54.4 ± 2.8, 61.5 ± 11.3, and 51.2 ± 6.3 cmH2O; all P < 0.05). When vardenafil was given following BAY 41-2272 or BAY 60-2770 no further urodynamic effects were observed. PDE5 as well as sGC protein expression was reduced in obstructed bladder tissue. CONCLUSIONS: Targeting sGC via stimulators or activators, which increase the levels of cGMP independent of endogenous NO, is as effective as vardenafil to reduce urodynamic signs of BO. Targeting the NO/cGMP pathway via compounds acting on sGC might become a new approach to treat BO.

[Effect of coicis semen oil on renal interstitial fibrosis in rats with unilateral urethral obstruction].

OBJECTIVE: To study the effect and mechanism of Coicis Semen oil (Kanglaite injection, KLT) on renal interstitial fibrosis induced by unilateral ureteral obstruction (UUO). METHOD: Fifty-four male SD rats were randomly divided into 3 groups, 6 in each group, the sham operated group, the model group, and the KLT group. Renal interstitial fibrosis model was established in rats by UUO. After administration of KLT (15 mL x kg(-1) x d(-1)) for 3, 7 and 14 days, the dynamic histological changes of renal interstitial tissues were observed and renal damage including tubular impairment and interstitial fibrosis were quantified on HE and Masson stained tissue sections. The expression of alpha-smooth muscle actin (alpha-SMA) and transforming growth factor-beta1 (TGF-beta1) were measured by immunohistochemistry staining sections. The protein expression of p-Smad2 and Smad7 were detected by Western blot respectively. RESULT: The degree of tubular damage in KLT group was much lower than that in UUO group (P < 0.05). The expression of alpha-SMA and TGF-beta1 was decreased in both UUO group and KLT group, while it was significantly lower in KLT group at every time point. The protein expression of p-Smad2 was obviously decreased while the protein expressions of Smad7 was obviously increased in KLT group, compared with the UUO group (P < 0.05). CONCLUSION: Coicis Semen oil could attenuate the tubulo-interstitial fibrosis, probable by intervening the TGF-beta/Smads signal transduction pathway of UUO rats.

New therapeutic options in prostatic enlargement.

Benign prostatic hyperplasia occurs in the majority of men past middle age. Transurethral prostatectomy has stood the test of time, but it may not be suitable for some men by virtue of concurrent medical problems or because patients prefer to avoid the risks and complications associated with surgery. This article outlines some of the alternative therapeutic options that are available.