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H Noto

Publications and source records attributed to H Noto.

At least 19 recordsLinked to original sources
PubMed1992

Modulation of the spinobulbospinal micturition reflex pathway in cats.

Micturition, which is mediated by a spinobulbospinal reflex pathway, can be modulated by various spinal and supraspinal mechanisms. This study examined modulation of the micturition reflex in decerebrate unanesthetized cats. Electrical stimulation of the pontine micturition center (PMC) elicited two types of bladder responses: small-amplitude short-duration responses due to direct activation of the bulbospinal pathway (PS-direct contractions) and large-amplitude long-duration reflex responses induced by PS-direct contractions but maintained by afferent feedback (PS-reflex contractions). Rectal and vaginal-cervical stimulation inhibited the PS-direct contractions, indicating inhibition of the descending or efferent limb of the micturition pathway. Stimulation of the central end of a transected S2 ventral root elicited recurrent inhibition of PS-reflex contractions but not of PS-direct contractions, indicating that recurrent inhibition does not directly affect the descending pathway. Continuous electrical stimulation (20 Hz) of the PMC decreased (53 +/- 21%) bladder capacity, presumably by affecting transmission in the pons or ascending input to the pons. Thus the micturition reflex could be modulated at several sites: the pons, the ascending or descending pathways, or spinal interneuronal sites.

Afferent Pathways↗
PubMed1992

The effect of alpha-2 agonists and antagonists on the upper urinary tract of the rat.

We examined the effect of the selective alpha-2 agonist dexmedetomidine and antagonist atipamizole on the upper urinary tract, renal pelvic pressure and ureteral peristalsis. Experiments were performed on twelve Sprague-Dawley female rats weighing 275-323 grams, with administration of urethane (1.2 micrograms/kg). Ventilatory support was provided through a tracheotomy. A continuous normal saline infusion was maintained through the left iliac vein at a rate of 2.5 ml/hr. Arterial pressure was measured at the left iliac artery, which was cannulated with a PE-100 tube connected to a pressure transducer. A mid-line incision was then made from the xyphoid to the symphysis to expose the left kidney, both ureters, and the bladder. The bladder was intubated and drained to avoid bladder pressure increase. Measurements of urine output rate were made from the right ureter and renal pelvic or ureteral pressure was measured using a nephrostomy placed into the pelvis. A ureterostomy was produced by introducing another catheter, into the upper segment of the left ureter for ureteral pressure measurements. The rats were divided into two groups as follows: 1) dexmedetomidine group (n = 6); injected intravenously with 2 micrograms/kg of dexmedetomidine dissolved in 0.5 ml saline. 2) atipamizole group (n = 6); injected intravenously with 2 micrograms/kg of atipamizole dissolved in 0.5 ml saline. Ureteral peristaltic frequency, baseline pressure, and contraction amplitude were compared before, after, and between the bolus injections of 2 micrograms/kg dexmedetomidine (n = 6) or 2 micrograms/kg atipamizole (n = 6) in 0.5 ml saline. The results showed that dexmedetomidine at 2 micrograms/kg produced a significant decrease in arterial pressure and an increase in urine output from 1.2 + 0.8 to 3.6 + 1.2 ml/min. There was no effect on the baseline pelvic pressure of 6.8 + 1.2 cmH2O or amplitude of the renal pelvic contractions: 3.5 + 0.6 cmH2O. The frequency of pelvic contractions was reduced from 0.37 + 0.03 to 0.27 + 0.02 Hz. Atipamizole at 2 micrograms/kg produced a significant reduction in urine flow rate of 1.1 + 0.8 to 0.6 + 0.2 ml/min. Atipamizole also showed no significant effects on baseline pelvic pressure or frequency, but increased the amplitude of pelvic contractions from control values of 3.0 + 0.9 to 3.4 + 0.9 cmH2O. Dexmedetomidine reduced both the baseline ureteral pressure of 8.5 + 2.4 and peristaltic contraction pressure of 11.5 + 2.3 cmH2O in 4/6 rats. Atipamizole reduced base-line ureteral pressure and increased peristaltic rate.(ABSTRACT TRUNCATED AT 400 WORDS)

Adrenergic alpha-Agonists↗
PubMed1992

[Effect of terazosin on lower urinary tract function in the male decerebrate dog].

The effect of terazosin on the lower urinary tract function was studied by combined recording of bladder and urethral pressures and external sphincter electromyogram in 8 male decerebrate dogs. Reflex micturitions were induced by bladder filling before and after terazosin. The statistical analysis was carried out on the urodynamic parameters. During the collecting phase, terazosin at doses of 10, 30 and 100 micrograms/kg produced a significant decrease in maximum urethral pressure in the dose dependent manner. Threshold pressure was significantly shown to decrease at doses of 30 and 100 micrograms/kg. In the urodynamic parameters of the emptying phase there was a significant decrease in maximum contraction pressure at 10 and 30 micrograms/kg, and in voided volume at 100 micrograms/kg. Terazosin seems to facilitate an initiation of the bladder contraction with a decrease in threshold pressure. In concludes that alpha 1 adrenergic activity seems to take an important role for the maintenance of the urethral pressure and to control the initiation of bladder contraction in modulation with threshold pressure.

Animals↗
PubMed1992

Effect of methylene blue on the vesicourethral function in the rats.

The bladder and urethral activities during the rhythmic bladder contractions were evaluated before and after the intraarterial administration of methylene blue, which prevents the activation of soluble guanylate cyclase. The methylene blue produced an increase in the bladder activity and a decrease in the urethral smooth muscle relaxant response induced with bladder contraction. The L-arginine/nitric oxide pathway seems to modulate the vesicourethral function.

Anesthesia↗
PubMed1992

[Vesical ultrasonography and internal examination of female patients with urethral syndrome].

Transabdominal ultrasonography of the bladder and internal examination were performed in 80 female patients without pyuria. They were divided into 3 groups: urethral syndrome with trigonitis (49 cases), asymptomatic trigonitis (16 cases) and normal bladder (15 cases) by cystoscopy. Ultrasonography of trigonitis with or without symptoms showed focal dilation of the submucosal low echo zone and mucosal irregularity around the bladder neck. On the sagittal view, the thicknesses from the surface of mucosa to that of muscle layer within 2 cm from the bladder neck were 4 +/- 1 mm (mean +/- standard deviation) in the group with urethral syndrome and in that with asymptomatic trigonitis, and 3 +/- 1 mm in the normal bladder group. Mucosa of the trigonitis with or without symptom is patients with significantly thicker than that of those with normal bladder (p less than 0.01). On internal examination, tenderness at the upper frontal wall of the vagina was present in 10 of 11 cases (91%) with urethral syndrome, in 2 of 8 cases (25%) with asymptomatic trigonitis and in one of 9 cases (11%) with normal bladder. There was a significant difference (p less than 0.005) between the degree of inflammation and the number of cases with tenderness at the frontal wall of the vagina. From these results, transabdominal ultrasonographic measurement of mucosal thickness around the bladder neck and internal examination for tenderness at the frontal wall of vagina are thought to be useful methods for diagnosis and follow-up of urethral syndrome.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

[An approach to stoma-less continent urinary diversion by uretero-ileoceco-proctostomy (ileocecorectal bladder)].

The current practice of continent urinary diversion still places the patients under the restraint of the stoma and intermittent catheterization. To overcome these problems, we developed a new technique of urinary diversion of which continent is controlled by the anal sphincter. The isolated ileocecal segment is intussuscepted and interposed between the ureters and the rectum. The conjoined ureters are anastomosed to the stump of the ileal limb, and the antimesenteric portion of the cecal limb is joined to the anterior wall of the rectum. The surgical procedure is simpler than that of the continent reservoirs currently employed. The intussuscepted ileocecal segment prevents fecal reflux to the upper urinary tract and may also inhibit carcinogenesis at the uretero-intestinal junction. Additionally, the rectal capacity is augmented by the side to side anastomosis between the cecal limb and the rectum. Our preliminary experience in 10 cases were satisfactory with respect to voiding function, antireflux mechanism of the intussuscepted ileocecal segment and quality of life. The results will justify further trials with this stomaless continent urinary diversion for those in whom the urethra cannot be used.

Anal Canal↗
PubMed1992

[Comparative study on nephrotoxicity of ionic and non-ionic contrast agents for drip infused urography].

The effects on renal function of an ionic and hyperosmolaric contrast agent (diatrizoate) and a non-ionic and slightly hypertonic agent (iohexol) for drip infused urography were compared on 60 patients with normal renal function. Urine samples were collected before and 30 minutes after drip infusion of contrast agent, and analyzed for albumin (ALB), gamma-glutamyl transpeptidase (gamma-GTP), N-acetyl-beta-glucosaminidase (NAG), beta 2 microglobulin (beta 2MG) and creatinine (CRE). The urinary excretion of proteins and enzymes was compared with urinary CRE. gamma-GTP, NAG and beta 2MG increased significantly after infusion of diatrizoate. gamma-GTP and beta 2MG increased significantly after infusion of iohexol. Excretion of ALB, gamma-GTP, NAG and beta 2MG was significantly higher after infusion of diatrizoate than after iohexol. The urinary concentration of CRE was significantly lower after infusion of diatrizoate than after iohexol. The degree of renal damage after urography was no related to the appearance of allergy to the contrast agent or age of patient. Therefore, the non-ionic and slightly hyperosmolaric iohexol may be less toxic to the kidneys than the ionic and hypertonic diatrizoate. This nephrotoxicity after drip infused urography is thought to be related mainly to the osmolarity of contrast agent.

Adult↗
PubMed1992

[Effects of Tsumura Chorei-to and Tsumura Chorei-to-go-shimotsu-to on patients with urethral syndrome].

Tsumura Chorei-to or Tsumura Chorei-to-go-shimotsu-to, was administered to 71 female patients with urethral syndrome 2.5 g three times a day for four weeks. Total efficacy rate of Tsumura Chorei-to in 34 cases was 71%. Tsumura Chorei-to was effective against pollakisuria, miction pain or discomfort, sense of residual urine and lower abdominal discomfort. Total efficacy rate of Tsumura Chorei-to-go-shimotsu-to in 37 cases was 57%. Tsumura Chorei-to-go-shimotsu-to was effective against dysuria, sense of residual urine and lower abdominal discomfort. Uutoward effect rates of Tsumura Chorei-to and Tsumura Chorei-to-go-shimotsu-to were 6% and 14%, respectively. Many of the untoward effects of these two drugs were epigastral discomfort. These two drugs are thought to be effective on patients with urethral syndrome.

Adult↗
PubMed1991

Properties of the descending limb of the spinobulbospinal micturition reflex pathway in the cat.

The micturition reflex is thought to be mediated by a spinobulbospinal reflex pathway passing through the rostral pons. This study examined the properties of the descending limb of the reflex pathway by monitoring the responses of the lower urinary tract to stimulation of the pons in the decerebrate cat. Electrical stimulation (300 microseconds pulses at 50 Hz intratrain frequencies, 300-500 ms trains, 0.5-15 V) in the region of the locus coeruleus (P 0.5-3.1/L 2-4/H to -2.75) was used to activate the descending excitatory pathway to the sacral parasympathetic nucleus. Low intensity stimulation induced small amplitude, short duration (14 +/- 11 cm H2O, 10 +/- 3 s) bladder contractions in a partially full bladder, whereas higher intensity stimulation induced large amplitude, long duration (69 +/- 29 cm H2O, 70 +/- 44 s) contractions which were similar to distension-induced reflex micturition contractions. The evoked bladder contractions coincided with a reduction in external urethral sphincter (EUS) EMG activity. Following bilateral L7-S3 dorsal root transection, electrical stimulation of the pons still elicited the small amplitude bladder contractions, but the larger amplitude, long duration micturition contractions were abolished. During these small evoked bladder contractions, a suppression of EUS activity still occurred following deafferentation, indicating a pontine mediated bladder/EUS synergy. It is concluded that the pons can initiate bladder contractions and coordinated bladder-sphincter activity, but that afferent feedback (via the dorsal roots) is needed to maintain the large amplitude micturition contractions.

Animals↗
PubMed1991

Electrophysiological analysis of the ascending and descending components of the micturition reflex pathway in the rat.

Electrophysiological techniques were used to examine the organization of the spinobulbospinal micturition reflex pathway in the rat. Electrical stimulation of afferent axons in the pelvic nerve evoked a long latency (136 +/- 41 ms) response on bladder postganglionic nerves, whereas stimulation in the dorsal pontine tegmentum elicited shorter latency firing (72 +/- 25 ms) on these nerves. Transection of the pelvic nerve eliminated these responses. Firing on the bladder postganglionic nerves was evoked by stimulation in a relatively limited area of the pons within and close to the laterodorsal tegmental nucleus (LDT) and adjacent ventral periaqueductal gray. Stimulation at sites ventral to this excitatory area inhibited at latencies of 107 +/- 11 ms the asynchronous firing on the bladder postganglionic nerves elicited by bladder distension. Electrical stimulation of afferents in the pelvic nerve evoked short latency (13 +/- 3 ms) negative field potentials in the dorsal part of the periaqueductal gray as well as long latency (42 +/- 7 ms) field potentials in and adjacent to the LDT. The responses were not altered by neuromuscular blockade. Similar responses were elicited by stimulation of afferent axons in the bladder nerves. The sum of the latencies of the ascending and descending pathways between the LDT and the pelvic nerve (i.e. 72 ms plus 42 ms = 114 ms) is comparable although somewhat shorter (22 ms) than the latency of the entire micturition reflex. These results provide further evidence that the micturition reflex in the rat is mediated by a spinobulbospinal pathway which passes through the dorsal pontine tegmentum, and that neurons in the periaqueductal gray as well as the LDT may play as important role in the regulation of the micturition.

Afferent Pathways↗
PubMed1991

Opioid modulation of the micturition reflex at the level of the pontine micturition center.

In precollicular decerebrate cats and dogs the intravenous administration of naloxone reduced urinary bladder capacity. Successive cystometrograms revealed that naloxone in doses of 10-100 micrograms/kg i.v. reduced the volume necessary to evoke micturition by 21-67% (mean 48%) in cats and 15-81% (mean 43%) in dogs, respectively. Microinjection of fentanyl (0.4-10 nM) into the pontine micturition center (PMC) increased the bladder capacity by 4-46% (mean 18%) in cats. Naloxone injected into the same site reversed the effect of fentanyl. Microinjection of naloxone (40-120 nM) into the PMC reduced the bladder capacity by 17-57% (mean 34%) in cats. These data indicate that endogenous opioid peptides may have a role in controlling micturition in both decerebrate cat and dog, and that the enkephalinergic inhibitory mechanisms are important in modulating the micturition reflex at the level of the pontine micturition center.

Animals↗
PubMed1991

[Experimental and clinical studies of urethral anesthesia on etiology and treatment of detrusor-sphincter dyssynergia].

We studied whether detrusor-sphincter synergia during micturition was obtained by means of urethral anesthesia with lidocaine hydrochloride in five thoracic spinal cats and eight clinical cases with detrusor-sphincter dyssynergia. In thoracic spinal cats with detrusor-sphincter dyssynergia, urethral anesthesia produced detrusor-sphincter synergia, an increase in the maximum bladder pressure and a decrease in the residual volume. In clinical cases with detrusor-sphincter dyssynergia, urethral anesthesia produced detrusor-sphincter synergia or a decrease in the external urethral sphincter activities during micturition, and a decrease in the maximum urethral closure pressure and the residual volume. There were no remarkable changes of the external urethral sphincter activities during urine storage phase before and after urethral anesthesia in both spinal cats and clinical cases. These results suggest that urethral anesthesia blocks the urethro-urethral contraction reflex and secondarily activates vesico-urethral relaxation reflex. The block of urethral sensory nerves is thought to effectively treat detrusor-sphincter dyssynergia.

Anesthesia, Local↗
PubMed1991

[Identification of effective region of the pons in response to inaperisone which facilitates urine storage].

To identify the effective region of the pons in response to inaperisone which facilitates urine storage, inaperisone (100 mM, 0.2 microliters) was injected into the nucleus locus coeruleus alpha (LCa, the pontine micturition center), the nucleus locus subcoeruleus (LSC, the pontine urine storage center) and the nucleus reticularis pontis oralis (PoO, micturition inhibitory region) of the decerebrate cats. On reflex micturition, inaperisone injection into the LSC decreased voiding volume, and increased residual volume and bladder capacity, significantly. However, there was no difference in the maximum bladder pressure before and after inaperisone injection into the LSC. Inaperisone injection into the LCa or the PoO had no influence on reflex micturition. These results suggest that effective region of the pons in response to inaperisone is the LSC, and that inaperisone facilitates the urine storage neural mechanism in the LSC.

Animals↗
PubMed1991

[Non-invasive imaging diagnosis of left renal vein compression causing hematuria. Part 1. Ultrasonography].

Left renal veins of 100 out-patients were examined by transabdominal ultrasonography to evaluate its usefulness in determining left renal vein compression which is causing renal bleeding. Ultrasonography revealed the left renal vein in 86 patients. In 61 of the 86 cases, the internal cavity of left renal vein was opened at least in diastolic phase, but in 23 cases, the internal cavity was closed between the abdominal aorta and the superior mesenteric artery in both systolic and diastolic phases. In the remaining 2 cases, left renal vein was compressed at a point where it intersected the right renal artery. Left renal vein compression was observed in 18 (69%) of the 26 cases which had been classified as idiopathic renal bleeding and in 7 (26%) of the 27 cases which had urinary tract diseases causing hematuria. In 33 cases which did not have hematuria, left renal vein compression was not observed. These results suggest that diagnosis of left renal vein compression causing renal bleeding is possible by transabdominal ultrasonography.

Adolescent↗
PubMed1991

[Non-invasive imaging diagnosis of left renal vein compression causing hematuria. Part 2. CT].

Left renal veins of 77 patients were examined by computed tomography (CT) to evaluate its usefulness in determining the left renal vein compression which is causing renal bleeding. From CT image, left renal vein compression was observed in 6 (86%) of the 7 cases which had been classified as idiopathic renal bleeding, in 9 (21%) of the 42 cases which had urinary tract diseases causing hematuria, and in 3 (11%) of the 28 cases which did not have hematuria. In 15 of the 18 cases of left renal vein compression, left renal vein was compressed between the superior mesenteric artery and the abdominal aorta, showing so-called nutcracker phenomenon. In the remaining 3 cases, however, the superior mesenteric artery provided sharp delineation from the abdominal aorta. The superior mesenteric artery and the abdominal aorta made the mean angle of 35.5 degree in patients with normal left renal vein, the mean angle of 45.4 degrees in those with left renal vein compression without nutcracker phenomenon, and the mean angle of 11.9 degrees in those with nutcracker phenomenon. CT was superior to ultrasonography, in revealing left renal vein compression.

Adult↗
PubMed1990

Pontine control of the urinary bladder and external urethral sphincter in the rat.

Neurons in the rostral pontine tegmentum are known to have an important role in controlling micturition. The present experiments used urethane anesthetized rats to examine the effects of electrical stimulation at various sites in the pons on bladder and external urethral sphincter activity and on the volume threshold for inducing micturition. Stimulation with short trains of pulses (50 Hz, 1-3 s trains, 1-15 V) in the laterodorsal tegmental nucleus (LDT), the periaqueductal grey (PAG) or the lateral parabrachial nucleus (L-PBN) elicited contractions of a partially filled, quiescent bladder. However stimulation during a bladder contraction aborted the contraction indicating that these areas have inhibitory as well as excitatory effects. Continuous stimulation (50 Hz) in the PAG or L-PBN during a cystometrogram decreased bladder capacity (mean decrease 36%). Conversely, continuous stimulation in the pontine reticular formation (in or near the dorsal subcoeruleus nucleus and medial parabrachial nucleus) increased bladder capacity (mean increase 50%). Stimulation at pontine sites (LDT, PAG and L-PBN) which elicited bladder contractions also elicited an increase in external urethral sphincter activity. A similar increase in urethral sphincter activity occurred during reflex micturition induced by bladder distension. These data suggest that bladder capacity and the coordination of bladder and external urethral functions are controlled by various neuronal populations in the rostral pons of the rat.

Animals↗