Effects of ethanol on responses of isolated rabbit urinary bladder and urethra

Associations Between Risk Factors and Overactive Bladder: A Meta-analysis

Age and body mass index are associated with increased risks of overactive bladder, whereas employment status is associated with a decreased risk of overactive bladder.

Objective

The purpose of this study was to investigate the risk factors of overactive bladder (OAB).

Methods

The PubMed, Embase, and Cochrane Library databases were retrieved through May 2016. Odds ratios (OR) or standard mean differences (SMDs) with 95% confidence intervals (CIs) were used to evaluate the associations between risk factors and OAB. Heterogeneity among studies was examined using χ² test based on the Q and I² tests.

Results

A total of 28 articles were analyzed in our study. The results suggested that age and body mass index were significantly higher in OAB patients than in non-OAB controls (SMDs [95% CIs], 0.30 [0.19–0.41] and 0.39 [0.24–0.53]). A significant negative association was found between employment status and OAB (OR [95% CIs], 0.64 [0.46–0.90]). However, sex, educational level, parity, vaginal delivery, race, menopause, marital status, smoking, and alcohol consumption were not significantly different in OAB and non-OAB control patients (ORs [95% CIs], 0.95 [0.59–1.55], 1.04 [0.82, 1.33], 0.98 [0.56–1.70], 1.66 [0.90–3.07], 0.98 [0.75–1.28], 1.84 [0.23–14.70], 0.97 [0.78–1.19], 0.91 [0.77–1.08], and 0.88 [0.71–1.09], respectively). In addition, the number of parities and vaginal deliveries in OAB patients also showed no significant differences compared with non-OAB control patients (SMDs [95% CI], 0.05 [−0.27 to 0.38] and −0.16 [0.40 to 0.09]).

Conclusions

This meta-analysis suggests that age and body mass index are associated with increased risks of OAB, whereas employment status is associated with a decreased risk of OAB. Further prospective studies with large sample sizes are needed to confirm this conclusion.

Hypoactivity of rat detrusor muscle in a model of cystitis: exacerbation by non-selective COX inhibitors and amelioration by a selective DP1 receptor antagonist

Various studies have confirmed that prostaglandins (PG) alter the bladder motor activity and micturition reflex in both human and animals. However, no sufficient data is reported about the effect of cyclooxygenase (COX) inhibitors neither in normal bladder physiology nor in pathological conditions. This study aims to compare the potential effects of some COX inhibitors with varying COX-1/COX-2 selectivities (indomethacin, ketoprofen, and diclofenac) with that of the selective COX-2 inhibitor (DFU) on bladder function. The role played by some PGs and their receptors in controlling detrusor muscle function in normal condition and in cystitis is also studied. Organ bath experiments were performed using isolated rat detrusor muscle. Direct and neurogenic contractions were induced using ACh and electric stimulation (EFS), respectively. A model of hemorrhagic cystitis was induced by single injection of cyclophosphamide (300 mg/kg) in rats, and confirmed by histophathological examination. Results are expressed as mean ± SEM of 5-9 rats. Alprostadil and iloprost (1 nM- 10 µM) concentration-dependently potentiated ACh (100 μM)- and EFS (4 Hz)-induced contraction, with maximum potentiation of 40.01 ± 5.29 and 27.59 ± 6.64%, respectively, in case of ACh contractions. In contrast, ONO-AE1-259 (selective EP₂ agonist, 1 nM-10 μM) inhibited muscle contraction. SC51322 (EP₁-antagonist, 10 μM) and RO1138452 (IP antagonist, 10 μM) inhibited both direct and neurogenic responses. Hemorrhagic cystitis reduced both ACh and EFS responses as well as the potentiatory effect of iloprost and the inhibitory effect of RO1138452 on ACh contractions. ONO-AE3-237 (DP₁ antagonist, 1 μM) significantly potentiated contractions in cystitis but showed no effect in normal bladder. A significant inhibition of contractile response was observed in presence of indomethacin, ketoprofen, and diclofenac at all tested concentrations (20, 50, and 100 μM). Highest effect was induced by diclofenac. The effect of these COX inhibitors on EFS contractions was intensified in case of cystitis, indomethacin being the most potent. Atropine (1 nM) significantly reduced indomethacin effect on ACh contraction only in normal rats. On the other hand, DFU (10^-6 M) significantly potentiated the contractile effect of ACh in case of cystitis although it showed no effect in normal rats. EP₁ receptors seem to play an important role in rat bladder contractility. DP₁ receptors as COX-2, on the other hand, gain an important role only in case of cystitis. The use of non-selective COX inhibitors in cystitis may be associated with bladder hypoactivity; selective COX-2 inhibitors may be a safer option.

Ethanol-mediated relaxation of guinea pig urinary bladder smooth muscle: involvement of BK and L-type Ca2+ channels

Mechanisms underlying ethanol (EtOH)-induced detrusor smooth muscle (DSM) relaxation and increased urinary bladder capacity remain unknown. We investigated whether the large conductance Ca(2+)-activated K(+) (BK) channels or L-type voltage-dependent Ca(2+) channels (VDCCs), major regulators of DSM excitability and contractility, are targets for EtOH by patch-clamp electrophysiology (conventional and perforated whole cell and excised patch single channel) and isometric tension recordings using guinea pig DSM cells and isolated tissue strips, respectively. EtOH at 0.3% vol/vol (~50 mM) enhanced whole cell BK currents at +30 mV and above, determined by the selective BK channel blocker paxilline. In excised patches recorded at +40 mV and ~300 nM intracellular Ca(2+) concentration ([Ca(2+)]), EtOH (0.1-0.3%) affected single BK channels (mean conductance ~210 pS and blocked by paxilline) by increasing the open channel probability, number of open channel events, and open dwell-time constants. The amplitude of single BK channel currents and unitary conductance were not altered by EtOH. Conversely, at ~10 μM but not ~2 μM intracellular [Ca(2+)], EtOH (0.3%) decreased the single BK channel activity. EtOH (0.3%) affected transient BK currents (TBKCs) by either increasing frequency or decreasing amplitude, depending on the basal level of TBKC frequency. In isolated DSM strips, EtOH (0.1-1%) reduced the amplitude and muscle force of spontaneous phasic contractions. The EtOH-induced DSM relaxation, except at 1%, was attenuated by paxilline. EtOH (1%) inhibited L-type VDCC currents in DSM cells. In summary, we reveal the involvement of BK channels and L-type VDCCs in mediating EtOH-induced urinary bladder relaxation accommodating alcohol-induced diuresis.

The association of diet and other lifestyle factors with the onset of overactive bladder: a longitudinal study in men

Objective:

To investigate associations between diet and non-dietary lifestyle factors and the onset of overactive bladder (OAB) in men.

Subjects:

Random sample of community-dwelling men aged 40 years plus.

Design and methods: Baseline data on urinary symptoms and diet were collected from 5454 men using a postal questionnaire and a food-frequency questionnaire. Follow-up data on urinary symptoms were collected from 4887 men in a postal survey one year later. Logistic regression analysis was used to investigate diet and lifestyle factors associated with onset of OAB in the men without OAB at baseline.

Results:

There was a highly significant negative association between beer intake at baseline and subsequent OAB onset (P = 0.001), with reduced risk at all levels of intake compared with those who seldom/never drank beer. Adjustment for total alcohol intake (g ethanol day−1) reduced the significance of the association (P = 0.02). None of the food groups studied was associated with OAB onset, with the possible exception of potatoes (P = 0.05), which showed an increased risk of onset at the highest level of consumption. Physical activity, smoking and obesity were not significantly associated.

Conclusions:

While most diet and lifestyle factors were not associated with OAB onset, the evidence from this prospective longitudinal study suggests that beer may have a protective role in the development of OAB. This could be due to a non-alcoholic ingredient as well as the alcohol content.

Effects of ethanol on intracorporeal structures of the rat

OBJECTIVE

Previous studies demonstrated that acute in vitro exposure of corpus cavernosal tissue to ethanol decreased its response to field stimulation and pharmacological stimulation. In the present study we investigated the effects of chronic ethanol consumption on the ultrastructure of cavernosal smooth muscle cells, elastic fibres and collagen content.

MATERIAL AND METHODS

Fourteen adult wistar rats were divided into a control group (n = 7, fed a standard diet and tap water) and an alcoholic group (n = 7, fed a standard diet and 5% (v/v) ethanol in drinking water and by increasing the ethanol concentration for every week, at the end of 6th week 30% (v/v) ethanol concentration was attained. Same dose was given until 12th week. At the end of 12th week blood samples were obtained and the ethanol concentrations were determined. The cavernosal tissues were obtained and immunohistochemical examinations were performed.

RESULTS

Immunohistochemical analysis revealed that chronic ethanol exposure markedly decreased the content of smooth muscle cells, elastic fibres and collagen type 4.

CONCLUSION

Our findings suggest that in this animal model chronic ethanol exposure decreases the percentage of staining for smooth muscle actin, elastin, and collagen type 4 which are the key structures fundamental for erection.

Effects of testosterone on neuromuscular transmission in rat isolated urinary bladder

Testosterone was examined for its effects on neuromuscular transmission in rat and shrew urinary bladder. In isolated preparations of detrusor muscle from sexually immature male rats (8-10 weeks old) at concentrations of 100-300 microM, it inhibited neuromuscular transmission in a concentration-dependent manner and it also inhibited responses to applied carbachol and diadenosine pentaphosphate (Ap(5)A, a P2X receptor agonist). Ethanol (at or above 38 mM), the solvent for testosterone, also caused significant inhibition of neurogenic contractions as well as carbachol- and Ap(5)A-induced contractions. In older, sexually mature male rats (over 16 weeks old), testosterone and ethanol had similar effects to those observed in the young male rat, although both were slightly less potent. In young virgin female rats (8-12 weeks old), testosterone and ethanol inhibited neuromuscular transmission; testosterone was approximately 1000 times more potent than in male rats, with a threshold concentration of 30 nM. In the insectivore, Suncus murinus, testosterone (0.1 microM-1 x mM) caused inhibition of neurogenic and chemogenic responses, but ethanol had no significant effect. Flutamide (50 microM), a genomic testosterone-receptor antagonist, did not inhibit any of the responses to testosterone. It is concluded that testosterone acts predominantly on a postjunctional nongenomic receptor to inhibit urinary bladder detrusor muscle contraction.

A queue paradigm formulation for the effect of large-volume alcohol intake on the lower urinary tract

We examine the urologic consequences of large-volume alcohol intake in light of recent advances in hollow viscera biomechanics and urinary tract pharmacology. Recent studies have shown that alcohol is depressive on the isolated rabbit detrusor. Patients teetering on or having manifest pelvi-ureteric junction obstruction or bladder outflow obstruction have been known to demonstrate symptoms on alcohol consumption. In men over 50, the cause is usually an enlarged prostate. Loin pain is precipitated in the case of the former and urinary retention in the latter case after consuming alcohol. Causation is difficult to prove for ethical reasons as well as the practical difficulties in running a prospective trial. It appears that a combination of rapid fill (due to diuretic effects), a weakened pump (due to the depressive effect of alcohol at least with the detrusor) and outlet obstruction lead to the loin pain and urinary retention seen in clinical practice. People liable to urinary tract obstruction would be well advised to avoid large volume alcohol intakes.

Chronic ethanol consumption impairs adrenoceptor- and purinoceptor-mediated relaxations of isolated rat detrusor smooth muscle

OBJECTIVE

To investigate the effects of chronic ethanol consumption on the reactivity of detrusor smooth muscle.

MATERIALS AND METHODS

Eight male rats received ethanol (7.2% v/v) in a modified liquid diet for 4 weeks. Two control groups were assessed; eight rats in one group were fed sucrose and received a liquid diet, and 12 rats in the second group received standard rat chow and water for 4 weeks. The reactivity of detrusor smooth muscle strips from ethanol-fed animals and control animals was evaluated in organ chambers.

RESULTS

The relaxation response elicited by isoprenaline or adenosine was unaffected in the both control groups while it was significantly inhibited, with decreased maximum responses and pD2 values, in the ethanol-fed group. Contractile responses of detrusor smooth muscle to carbachol or 80 mmol/L KCl and relaxant responses to papaverine were similar in the control groups and the ethanol-fed group. There was no change in agonist potency among the groups.

CONCLUSION

Chronic ethanol consumption impairs beta-adrenoceptor- and purinoceptor-mediated relaxation but not cholinoceptor-mediated contraction of the rat detrusor smooth muscle. Thus, it appears that different regulatory mechanisms are involved in ethanol-induced alterations in beta-adrenergic, purinergic and muscarinic receptors in detrusor strip.

Effects of ethanol and its metabolite acetaldehyde on responses of the rat bladder

OBJECTIVE

To investigate the pharmacological effects of ethanol and its metabolite acetaldehyde on isolated rat bladder muscle, and thus assess the potential influence of ethanol ingestion on the risk of urinary retention in patients with benign prostatic hyperplasia.

MATERIALS AND METHODS

Isometric tension changes of isolated rat bladder muscle strips were recorded in an organ bath using a pressure transducer. The acute or prolonged effects of ethanol (1-4%) or acetaldehyde (0.01, 0.1 or 1 mmol/L) were assessed on resting tension, electrical field stimulation (EFS), and bethanechol- (0.5 mmol/L), ATP- (2 mmol/L) or KCl- (127 mmol/L) induced contraction. To determine the mechanism of acetaldehyde-induced stimulation, an antihistamine, diphenhydramine was used after bethanechol stimulation.

RESULTS

At the concentrations used, ethanol and acetaldehyde did not change the pH of the bathing medium. The resting tension of the muscle was not changed by ethanol, and acetaldehyde caused only a small increase in baseline tone at 1 mmol/L. Incubation with ethanol or acetaldehyde significantly suppressed contractility induced by EFS, bethanechol, ATP or KCl at each concentration (P<0.05). Contractions induced by all drugs were not changed significantly by the acute application of ethanol and the acute application of acetaldehyde did not affect contractions induced by ATP or KCl. However, EFS- or bethanechol-induced contractions were significantly enhanced (P<0. 05). The acetaldehyde-induced effects were completely blocked by the H1 antagonist, diphenhydramine (10 micromol/L).

CONCLUSIONS

Ethanol did not affect resting tension but acetaldehyde and ethanol suppressed bladder muscle contractions. However, direct acetaldehyde-stimulation may release histamine and enhance contractility. This suggests that chronic alcoholism rather than acute intoxication is more likely to provoke urinary retention.