Hiro Kiwamoto

EXISTENCE OF A β3-ADRENOCEPTOR AND ITS FUNCTIONAL ROLE IN THE HUMAN URETER

Purpose: We tried to determine the β-adrenoceptor (AR) subtypes distributed in the human ureter and to clarify their functional role in ureteral relaxation.Materials and Methods: 1) Effects of β-AR agonists on either spontaneous or KCl-induced contractions of the human ureter and the antagonism by β-AR antagonists on isoprenaline (a non-selective β-AR agonist)-induced effects were evaluated in vitro. 2) Displacement by β-AR antagonists of [3H]-dihydroalprenolol binding to a membrane preparation derived from human ureteral smooth muscle was evaluated. 3) A reverse transcription polymerase chain reaction assay was performed to determine the expression of the mRNA for β1-, β2- and β3-ARs in human ureteral smooth muscle.Results: 1) Isoprenaline and procaterol (a β2-AR agonist) concentration-dependently suppressed both spontaneous and KCl-induced contractions of the human ureter. The β3-AR agonists, CGP-12177A and CL-316243, also suppressed these ureteral contractions, but dobutamine (a β1-AR agonist) had litt...

URINARY INCONTINENCE IN SENILE DEMENTIA OF THE ALZHEIMER TYPE (SDAT)

Twenty patients (1 male and 19 females) with senile dementia of the Alzheimer type were studied using cystometry in combination with sphincter electromyography, brain computed tomography (CT) and evaluating the activities of daily life (ADL), with special reference to urinary incontinence. Seven of the patients were continent and the remainder were incontinent. Cystometry revealed uninhibited detrusor contraction in 8 out of the 13 incontinent patients, while no uninhibited contraction was found in 7 continent patients. There was a significant correlation between uninhibited detrusor contraction and urinary incontinence (p 0.05). Brain CT showed that the degree of brain atrophy was more severe in those with uninhibited contraction than those without (p 0.05). There was no clear relationship between sphincter coordination and the occurrence of incontinence. The ADL score tended to be lower in incontinent patients, although no significant difference was apparent (0.05 p 0.1). Uninhibited detrusor contraction and poor ADL functioning caused by brain atrophy are thought to be major causes of urinary incontinence in patients with senile dementia of Alzheimer type.

Endoscopic correction of vesicoureteral reflux in patients with neurogenic bladder dysfunction

Transurethral injection of Teflon paste (TUI) was carried out in 24 ureters of 16 patients with vesicoureteral reflux (VUR) secondary to neurogenic bladder dysfunction at an age ranging from 4 to 77 years, and the results were compared with those of conventional open surgery. During the mean follow-up period of 20.1 months, reflux disappeared in 19 ureters (79%), so that the success rate of endoscopic operation was considered to be satisfactory as compared with that of conventional open surgery, in which reflux disappeared in 16 (80%) of 20 ureters in 16 patients with neurogenic bladder dysfunction at our department. No exacerbation of hydronephrosis was observed postoperatively, and no complication was noted. This procedure, which is minimally invasive and technically simple, may be regarded as the first choice for VUR secondary to neurogenic bladder dysfunction.

Functional electrical stimulation in the management of incontinence: Studies of urodynamics

Intermittent functional electrical stimulation (FES) was employed for the control of incontinence. One FES session lasted for 30 minutes. It was repeated at intervals of 3 days to 1 week via an anal plug electrode.The success rate was 64% in 41 patients with pollakiuria, urgency and/or urge incontinence, and 43% in 7 patients with stress incontinence. Detrusor activity measured by cystometry did not correlate significantly with the effect on subjective symptoms and the urethral pressure did not increase. The remarkable clinical effect was observed in patients with overactive detrusor function.It seems that FES indirectly inhibits detrusor contraction by suppressing the intrasacral pathway for detrusor activity.

Burst activities of cremasteric motor units

Electromyographic activities of the ipsilateral creamaster muscle evoked by electrical stimulation of either the thigh or the penis were analyzed for latencies and burst durations. Response latencies were 30 ms on thigh stimulation and 30–35 ms on penile stimulation. With the increase in stimulus intensity the latencies decreased to 30 ms in both cases. The changes were stepwise, indicating the switching between different reflex arcs. The burst duration on thigh stimulation was about 50 ms, and that for penile stimulation was 45 ms. Impulses producing the burst consisted of larger and smaller spikes, and this indicates the grouping of motor units for wing tonic and phasic units. The results suggest the existence of parallel neuronal circuitries for the spinal cremateric reflex, and it is expected to provide a clue for evaluating the clinical significance of the cremasteric reflex.

Identification of muscarinic receptor subtypes of cultured smooth muscle cells and tissue of human bladder body

Abstract Background: Muscarinic receptor subtypes of cultured smooth muscle cells from the human bladder body were investigated by the receptor binding assay method. The result was compared with that obtained from the human bladder body tissue to confirm whether the receptor subtypes of the cells are not changed after several passages of cell culture.