naloxone and Urinary-Incontinence

To evaluate the effect of St. John's wort (SJW), an effective and safe herbal antidepressant, on rat bladder contractility. Recent data have suggested a strong association between depression and urinary incontinence.. Strips were cut from the bladder body and placed in organ baths containing Krebs solution. Contractions were induced by electrical field stimulation (EFS) and, in some experiments, by exogenous alpha,beta (alpha,beta)-methylene adenosine triphosphate.. St. John's wort was significantly more active in inhibiting the EFS-induced contractions than the alpha,beta-methylene adenosine triphosphate-induced contractions, suggesting both a presynaptic site of action and a direct inhibition of bladder smooth muscle. The inhibitory effect of SJW on EFS-induced contractions was unaffected by methysergide, haloperidol, phentolamine plus propranolol (antagonists that block the action of the neurotransmitters 5-hydroxytriptamine, dopamine, and noradrenaline on their own receptors), the L-type calcium channel antagonist verapamil, capsazepine (which blocks the vanilloid receptor), or cannabinoid CB1 receptor antagonist SR141716A. However, the opioid receptor antagonist naloxone significantly reduced the inhibitory effect of SJW on EFS-induced contractions. Among the chemical constituents of SJW tested, hyperforin and, to a lesser extent, the flavonoid kaempferol showed inhibitory effects.. The results of our study demonstrated that SJW inhibits excitatory transmission of the rat urinary bladder and also directly inhibits smooth muscle contractility. The inhibitory effect on excitatory transmission could involve, at least in part, opioid receptors. SJW may be evaluated for its possible use in treating urinary incontinence in depressed patients.

Topics: Acetylcholine; Adenosine Triphosphate; Animals; Anthracenes; Antidepressive Agents; Atropine; Bridged Bicyclo Compounds; Capsaicin; Depression; Electric Stimulation; Female; Haloperidol; Hypericum; Kaempferols; Male; Methysergide; Muscle Contraction; Muscle, Smooth; Naloxone; Perylene; Phentolamine; Phloroglucinol; Piperidines; Plant Extracts; Propranolol; Pyrazoles; Quercetin; Rats; Rats, Wistar; Rimonabant; Rutin; Terpenes; Tetrodotoxin; Urinary Bladder; Urinary Incontinence; Verapamil

The effect of treatment with thyrotropin-releasing hormone (TRH) or naloxone on the neurologic impairment after spinal cord injury was studied in rats with the severest neurologic impairment (complete paraplegia, no withdrawal response upon tail pinching, and urinary incontinence) 24 h and 7 days after injury. Subcutaneous treatment with TRH (2.5, 10 and 40 mg/kg per day) once daily for 7 consecutive days starting 24 h or 7 days after injury improved the neurologic function in the rats with cord injury in a dose-related manner, with a minimum effective dose of less than 2.5 mg/kg per day in both cases. However, subcutaneous treatment with naloxone (40 mg/kg per day) once daily for 7 consecutive days starting 24 h after injury did not exert any beneficial effects on neurologic function. These results indicate that TRH but not naloxone treatment starting 24 h and as late as 7 days after injury is effective in rats with the severest neurologic impairment following spinal cord injury. Thus, it is suggested that the duration of the effectiveness of late treatment with TRH on the neurologic impairment in rats with spinal cord injury is more than 1 week, while the duration with naloxone is less than 24 h.

Topics: Animals; Dose-Response Relationship, Drug; Male; Naloxone; Nervous System; Paraplegia; Rats; Rats, Inbred Strains; Spinal Cord Injuries; Thyrotropin-Releasing Hormone; Time Factors; Urinary Incontinence

In the ventral horn of the sacral spinal cord of the cat, opioid terminals are preferentially localized in Onuf's nucleus, an area containing motor neurons that innervate the striated muscle of the external urethral sphincter. The present study was undertaken to 1) compare the effects of selective opioid agonists on sphincter reflex pathways with the effects of these drugs on hindlimb reflexes and urinary bladder reflexes and 2) determine if the physiological inhibition of sphincter reflexes, which accompany bladder contractions, is mediated by endogenous opioids. The effects of intrathecal (i.t.) and i.v. drug administration on bladder activity, sphincter reflexes and reflexes to the hindlimb musculature were monitored in chloralose-anesthetized cats. Ethylketocyclazocine (0.05-500 micrograms i.t.) produced a dose-dependent, naloxone-sensitive, inhibition of sphincter reflexes to less than 10% of control amplitude while having no consistent effects on hindlimb reflexes or bladder activity. D-Ser2-leu5-enkephalin-thr6 (DSLET; 0.1-2.0 micrograms i.t.) abolished rhythmic bladder activity, while having no effects on sphincter or hindlimb reflexes. Larger doses of DSLET (5.0-10 micrograms i.t.) produced a modest reduction of sphincter reflexes (to 60% of control amplitude), without affecting hindlimb reflexes. Naloxone (50 micrograms i.t.) reversed DSLETs marked inhibition of bladder activity, whereas large doses (greater than 250 micrograms i.t.) only partially antagonized DSLETs weak inhibition of sphincter reflexes. Morphine (5-500 micrograms i.t.) had no consistent effect on any of the measures.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Cats; Cyclazocine; Enkephalin, Leucine; Enkephalin, Leucine-2-Alanine; Ethylketocyclazocine; Female; Morphine; Naloxone; Oligopeptides; Receptors, Opioid; Receptors, Opioid, kappa; Reflex; Urethra; Urinary Bladder; Urinary Incontinence

In order to investigate the influence of the endorphins on lower urinary tract function we antagonized the endogenous opiates with naloxone. We performed urodynamic examination in 17 incontinent women, administered intravenously 0.4 mg naloxone, and repeated the urodynamic examination. Bladder volume and pressure were not influenced by naloxone; the maximum urethral pressure showed a slight and urethral closure pressure a significant rise after naloxone treatment. Contrary to other authors, our results do not support a role of endorphins in lower urinary tract function.

Topics: Adult; Endorphins; Female; Humans; Male; Middle Aged; Naloxone; Pressure; Urethra; Urinary Bladder; Urinary Incontinence; Urodynamics