The effects of α_1A‐adrenoceptor antagonists on the urethral perfusion pressure of the female rat

Abstract

OBJECTIVE To assess the effects of α1A‐adrenoceptor antagonists on urethral perfusion pressure (UPP) in the female rate and their therapeutic potential for treating female bladder outlet obstruction (BOO). MATERIALS AND METHODS A cannula was inserted into the femoral arteries of female rats to administer tamsulosin (group I), doxazosin (group II) or phentolamine (group III) and to monitor systemic blood pressure. Tamsulosin was also administered to male rats (group IV). UPP and vesical pressures (Pves) were monitored using a triple‐lumen catheter. RESULTS After administration of tamsulosin to group I the frequency of bladder contractions decreased significantly and the duration of minimal urethral relaxation with high‐frequency oscillations (HFOs) was significantly prolonged. Except for mean arterial blood pressure (MAP), none of the variables in group I differed significantly from those in group II and group III. The change in MAP after tamsulosin treatment was significantly lower than after doxazosin or phentolamine. Except for the maximum Pves, which was significantly higher in males (group IV) than in females of group I, the UPP and Pves curves of male rats were similar to those of females before giving tamsulosin. The prolonged frequency and duration of HFO in group IV (with tamsulosin) were significantly different from those of females. CONCLUSIONS The α1A‐adrenergic receptor may be a functional subtype in the female rat urethra. α1A‐adrenoceptor antagonists prolonged the duration of HFOs and decreased the frequency of involuntary bladder contraction. It is possible that treatment with α1A‐adrenoceptor antagonists would not only improve obstructive symptoms, but also ameliorate irritative symptoms by prolonging HFOs and the frequency of involuntary bladder contractions.

The Relaxant Effect of Ginseng Saponin on the Bladder and Prostatic Urethra: An in vitro and in vivo Study

“…Under general anesthesia by intraperitoneal urethane administration, the rats were prepared according to the methods of Bae et al [17]. To monitor the UPP and P ves , we used a custom-designed triple-lumen catheter.…”

Sexually dimorphic urethral activity in response to pharmacological activation of 5-HT1A receptors in the rat

“…Seven isovolumetric IVP and UPP parameters were measured: 1) the maximum amplitude of bladder contraction, 2) the duration of bladder contraction, 3) the area of reflex bladder contraction, 4) the frequency of bladder contraction, 5) the UPP baseline of the continence phase (i.e., the average UPP during bladder relaxation), 6) the UPP baseline of the voiding phase [i.e., the average UPP during the period of high-frequency oscillations (HFOs)], and 7) the difference between the two UPP baselines (i.e., the UPP baseline of the continence phase minus the UPP baseline of the voiding phase) ( Fig. 1) (2,7,45).…”

Relaxation Effect of Phosphodiesterase-5 Inhibitor on the Animal Bladder and Prostatic Urethra: in vitro and in vivo Study

“…Changes of P ves and UPP were Effect of PDE-5 Inhibitor on Lower Urinary Tract Urol Int 2010;84:231-235 233 monitored after giving udenafil (1.0 mg/kg) via the femoral artery. Detail parameters of the experiment were intercontraction interval of isovolumetric vesical contraction (ICI), baseline UPP (UPP basal ), minimal UPP during urethral relaxation (UPP min ), duration of high-frequency oscillation (D hfo ) and vesical pressure change between peak and baseline pressure (P vesdif ) as described by Bae et al [8] .…”

“…To monitor the UPP and P ves , the rats were prepared using the method of Bae et al [8] which is a modified model of Jung et al [9] . After exposing the bladder and proximal urethra via a midline abdominal incision, the UPP was monitored using a customdesigned triple-lumen catheter, which consisted of an outer catheter (8-french cut-down tube) containing two polyethylene catheters of different sizes (PE-160 and PE-50) connected to a pipette tip.…”