The role of cholinesterases in rat urinary bladder contractility

Diagnostic Potential of Low Serum Platelet, Albumin and Prolong PT-INR for Overactive Bladder and Nocturia in Chronic Hepatitis-Related Liver Cirrhosis

Overactive bladder (OAB) is defined as urgency, usually with frequency, nocturia, and incontinence. Patients with liver cirrhosis often present with urinary complaints. The possible reason for this is fluid redistribution, which may induce OAB resulting from portal hypertension and ascites. We conducted this study to investigate predictors of OAB in cirrhotic patients. A total of 164 patients with chronic viral hepatitis-related liver cirrhosis were enrolled and 158 (96.3%) completed the Overactive Bladder Symptoms Score (OABSS) questionnaire. Age, severity of liver cirrhosis, comorbidities, serum sodium level, use of diuretics, body mass index and renal function were also recorded. In the study cohort, the prevalence of OAB was 31.01% and the prevalence of urge incontinence (OAB wet) was 18.3%. Patients with an urgency score ≥2 in OABSS had a significantly lower platelet level (p = 0.025) regardless of the use of diuretics. In addition, 98 patients (62%) with nocturia and 29 patients (18%) with urge incontinence had significantly lower levels of serum albumin (p = 0.028 and 0.044, respectively). In conclusion, patients with liver cirrhosis have a high prevalence of overactive bladder. A low platelet and low serum albumin level in these patients may be predictors for overactive bladder. And longer PT-INR is also a possible biomarker for nocturia.

Impairment of cholinergic bladder contractility in rat model of type I diabetes complicated by cystitis: Contribution of neurotransmitter-degrading ectoenzymes

Parasympathetic regulation of urinary bladder contractions primarily involves acetylcholine release and activation of detrusor smooth muscle (DSM) muscarinic acetylcholine (mACh) receptors. Co-release of ATP and activation of DSM purinergic P2X1-receptors may participate as well in some species. Both types of neuromuscular transmission (NMT) are impaired in diabetes, however, which factors may contribute to such impairment remains poorly understood. Here by using rats with streptozotocin(STZ)-induced type I diabetes (8th week after induction) we show that contribution of atropine-sensitive m-cholinergic component to the contractions of urothelium-denuded DSM strips evoked by electric field stimulation (EFS) greatly increased when diabetic bladders presented overt signs of accompanying cystitis. Modeling of hemorrhagic cystitis alone in control rats by cyclophosphamide injection only modestly increased m-cholinergic component of EFS-contractions. However, exposure of DSM strips from control animals to acetylcholinesterase (AChE) inhibitor, neostigmine (1-10 μM) largely reproduced alterations in EFS contractions observed in diabetic DSM complicated by cystitis. Ellman's assay revealed statistically significant 31% decrease of AChE activities in diabetic vs. control DSM. Changes in purinergic contractility of diabetic DSM were consistent with altered P2X1-receptor desensitization and re-sensitization. They could be mimicked by pharmacological inhibition of ATP-degrading ecto-ATPases with ARL 67156 (50 μM), pointing to compromised extracellular ATP clearance as underlying reason. We conclude that decreased AChE activities associated with diabetes and likely cystitis provide complementary factor to the described in literature altered expression of mACh receptor subtypes linked to diabetes as well as to cystitis to produce dramatic modification of cholinergic NMT.

Effectiveness of intramuscular neostigmine to accelerate bladder emptying after spinal anesthesia

Purpose

Postoperative urinary retention (POUR) is one of the most common complications following spinal anesthesia. Spinal anesthesia may influence urinary bladder function due to interruption of the micturition reflex. Urinary catheterization is the standard treatment of POUR. Urinary catheter insertion is an invasive procedure, which is associated with catheter-related infections, urethral trauma, and patient discomfort. The purpose of this study was to determine the effectiveness of intramuscular (IM) neostigmine to accelerate bladder emptying after spinal anesthesia.

Patients and methods

A total of 36 patients undergoing lower abdominal (except for pelvic, urologic, anorectal, and hernia surgery) and lower extremity surgery under spinal anesthesia were divided into two groups randomly (n=18), to either neostigmine (N) group or control (C) group. Neostigmine 0.5 mg (N group) or NaCl 0.9% (C group) was administered intramuscularly when Bromage score 0 and sensory level sacral two have been achieved. The time to first voiding after IM injection and the time to first voiding after spinal anesthesia were measured.

Results

The time to first voiding after IM injection was significantly faster (P≤0.05) in the N group than that in the C group, with median time as 40 minutes (20–70 minutes) and 75 minutes (55–135 minutes), respectively. Time to first voiding after spinal anesthesia was also significantly faster (P≤0.05) in the N group than that in the C group (mean of 280.8±66.6 minutes and 364.2±77.3 minutes, respectively).

Conclusion

IM neostigmine effectively accelerates bladder emptying after spinal anesthesia.

Specific inhibition of acetylcholinesterase as an approach to decrease muscarinic side effects during myasthenia gravis treatment

Non-selective inhibitors of cholinesterases (ChEs) are clinically used for treatment of myasthenia gravis (MG). While being generally safe, they cause numerous adverse effects including induction of hyperactivity of urinary bladder and intestines affecting quality of patients life. In this study we have compared two ChEs inhibitors, a newly synthesized compound C547 and clinically used pyridostigmine bromide, by their efficiency to reduce muscle weakness symptoms and ability to activate contractions of urinary bladder in a rat model of autoimmune MG. We found that at dose effectively reducing MG symptoms, C547 did not affect activity of rat urinary bladder. In contrast, at equipotent dose, pyridostigmine caused a significant increase in tonus and force of spontaneous contractions of bladder wall. We also found that this profile of ChEs inhibitors translates into the preparation of human urinary bladder. The difference in action observed for C547 and pyridostigmine we attribute to a high level of pharmacological selectivity of C547 in inhibiting acetylcholinesterase as compared to butyrylcholinesterase. These results raise reasonable hope that selective acetylcholinesterase inhibitors should show efficacy in treating MG in human patients with a significant reduction in adverse effects related to hyperactivation of smooth muscles.

Effect of lumbar epidural administration of neostigmine on lower urinary tract function

BACKGROUND

Neostigmine is cholinomimetic and is used for postoperative analgesia. Its urodynamics effects on voiding function have not been elucidated.

MATERIALS AND METHODS

Adult patients without bothersome voiding symptoms planned for rigid cystoscopy under local anesthesia were enrolled. They underwent multichannel urodynamics (filling cystometry and pressure-flow study) before and 30 min after lumbar epidural administration of Neostigmine (2 microg/kg).

RESULTS

Indications for cystoscopy were check examination for follow up of carcinoma urinary bladder (n = 3), staging for carcinoma cervix (5), and removal of ureteral stent (4). Patients' mean age was 51.9 +/- 11.7 years and international Prostatic symptom score 2.34 +/- 3.41. A trend of decreased maximum cystometric capacity (MCC) was observed after Neostigmine (413.50 +/- 142.45 ml vs. 357.00 +/- 145.62 ml; P = 0.056) without any change in end-filling pressure. Five patients developed detrusor overactivity (DO) and one had increase in its amplitude (P = 0.031). Four patients developed rhythmic rectal contractions and one had increase in its amplitude (P = 0.219). There was no difference in any of the voiding parameters. Mean Visual Analog Pain Score (VAS scale 0-10) during cystoscopy for this group was significantly lower than that in a similar group of patients who did not receive Neostigmine prior to rigid cystoscopy (1.16 +/- 0.94 vs. 4.57 +/- 1.45; P = 0.0001). The drug was well tolerated in majority of the patients.

CONCLUSION

Epidural Neostigmine is effective in providing analgesia during diagnostic rigid cystoscopy. It leads to development of DO and decrease in bladder capacity without any effect on voiding function. These findings may help clinicians to use it for transurethral procedure-related pain relief without apprehension of voiding difficulty.

Relationship between serum cholinesterase level and urinary bladder activity in patients with or without overactive bladder and/or neurogenic bladder

We compared the serum cholinesterase (ChE) level and various parameters between patients with or without overactive bladder (OAB) and/or neurogenic bladder (NB). A total of 258 patients who met the following criteria were enrolled: the presence/absence of OAB and/or NB was documented, laboratory data were available, and liver and renal functions were normal. Patients were divided into the 3 groups: 1) a NB+/OAB+ group who had both NB and OAB, 2) a NB-/OAB+ group who had OAB alone, and 3) an OAB- group who did not have OAB. The relationship between the presence of OAB and various biochemical parameters were examined, as well as the therapeutic outcome in relation to the same biochemical parameters. Forty-three patients had both NB and OAB (NB+/OAB+), 66 patients had OAB without NB (NB-/OAB+), and 149 patients had no OAB (OAB-). Serum ChE, total protein, and albumin levels were lower in the NB-/OAB+ group than the NB+/OAB+ group or the OAB- group. In the NB-/OAB+ group, a higher serum albumin or ChE level was associated with a better therapeutic outcome. These results suggest that a decrease of serum ChE level is related to the occurrence of OAB and the poor response to treatment in OAB patients without NB.

Differential effects of TAK-802, a selective acetylcholinesterase inhibitor, and carbamate acetylcholinesterase inhibitors on contraction of the detrusor smooth muscle of the guinea pig

The aim of this study was to compare the effects of TAK-802, a novel acetylcholinesterase (AChE) inhibitor, and carbamate AChE inhibitors on the detrusor smooth muscle contractility in vitro using isometric tension measurements. The effects of drugs on the nicotine-induced contractions and basal tone of the isolated detrusor muscle of the guinea pig were examined. All of the drugs, namely, TAK-802, distigmine, neostigmine and pyridostigmine, enhanced the nicotine-induced contractions of the muscle strips in a concentration-dependent manner. On the other hand, while neostigmine and pyridostigmine markedly increased the basal tone, and distigmine slightly but significantly increased the basal tone, TAK-802 had no influence on the basal tone of the muscle strips at all. However, following co-treatment with tetraisopropyl pyrophosphoramide, a selective butyrylcholinesterase (BuChE) inhibitor, TAK-802 also did increase the basal tone. The increase of the basal tone by all of the above treatments was completely abolished by atropine. These results reveal that while all the four AChE inhibitors enhanced endogenous acetylcholine-induced contractions, their effects on the basal tone were clearly different. The effect of carbamate AChE inhibitors of increasing the basal tone could be partly attributed to their dual inhibition of both AChE and BuChE, because both cholinesterases may play a critical role in maintaining the resting tension of the urinary bladder. TAK-802, however, did not increase the basal tone of the detrusor muscle strips, probably because of its selective inhibitory effect against AChE. The effect of carbamate AChE inhibitors on the basal tone of the detrusor muscle may explain the decrease of bladder compliance observed in our previous study on guinea pigs as well as the deterioration of the bladder-storage function reported with their clinical use.

Effects of TAK-802, a novel acetylcholinesterase inhibitor, and various cholinomimetics on the urodynamic characteristics in anesthetized guinea pigs

In the present study, we investigated the effects of cholinomimetic drugs on the urodynamic characteristics in anesthetized guinea pigs. 8-[3-[1-[(3-fluorophenyl)methyl]-4-piperidinyl]-1-oxopropyl]-1,2,5,6-tetrahydro-4H-pyrrolo[3,2,1-ij]quinolin-4-one (TAK-802), a novel acetylcholinesterase inhibitor, (0.003-0.03 mg/kg, i.v.) increased the voided volume and the maximum flow rate without affecting either the intravesical pressure or the bladder compliance. Distigmine (0.03-0.3 mg/kg, i.v.) and neostigmine (0.01-0.1 mg/kg, i.v.), both carbamate acetylcholinesterase inhibitors, while not increasing the maximum flow rate, increased the intravesical pressure at the maximum flow rate. They also decreased the bladder compliance. Bethanechol (0.1-1 mg/kg, i.v.), a muscarinic receptor agonist, decreased the voided volume and the bladder compliance but did not affect the maximum flow rate. TAK-802 did not affect the intraurethral pressure at doses of up to 0.03 mg/kg in anesthetized guinea pigs. Distigmine increased the intraurethral pressure when administered at the dose of 0.3 mg/kg, and the effect was completely abolished by pretreatment with d-tubocurarine. These results suggest that TAK-802 reinforces the bladder-voiding functions by increasing the bladder contractility without decreasing the storage function. On the other hand, carbamate acetylcholinesterase inhibitors not only deteriorate the voiding function by inducing contraction of the external urethral sphincter muscle, resulting in increasing the urethral resistance, but also cause deterioration of the storage function. Bethanechol obviously decreased the bladder capacity, possibly due to a direct contractile effect on the detrusor smooth muscle. TAK-802 may therefore be a more useful drug than either carbamate acetylcholinesterase inhibitors or muscarinic receptor agonists in the treatment of voiding dysfunction associated with impaired detrusor contractility.