Itaru Moriya

Role of the Sympathetic Nerve in Bladder and Urethral Sphincter Function During the Micturition Cycle in the Dog Evaluated by Pressure Flow EMG Study

The role of the sympathetic nerve on bladder and urethral sphincter function during the whole micturition cycle, including the collecting and emptying phases, was evaluated on 10 decerebrated dogs by pressure flow EMG study. A series of experiments was performed before and after hypogastric nerve transection. In the control condition and after hypogastric nerve transection, reflex micturition with bladder contraction and spasmodic rhythmic sphincter contractions occurred. Urodynamic parameters of the micturition cycle were statistically compared between control and nerve transection experiments. Threshold volume, threshold pressure and opening pressure showed a small but significant change after nerve transection. A decrease in voided volume seems to be secondarily accompanied with a decrease in threshold volume. It seems that adrenergic nerves play a certain role in bladder function during the collecting phase of the micturition cycle.

Effects of the Autonomic Antagonists on Canine Urethral Reponses to Autonomic Nerve Stimulation

The effects of the autonomic antagonists on urethral activity was studied in female dogs. Urethral responses produced by autonomic nerve stimulation were measured with pressure and motility changes in control conditions and after administration of autonomic antagonists. Phentolamine and guanethidine reduced both hypogastric and pelvic nerve mediated responses. It seems that urethral smooth muscle function is greatly influenced by adrenergic drugs.

Role of striated urethral sphincter on the voiding cycle in the decerebrated dog.

The role of the striated urethral sphincter on the dynamics of micturition was studied using 4 decerebrated dogs. The voiding cycles were analyzed by pressure flow EMG and pressure flow plot studies before and after the administration of suxamethonium. In the control condition, highly reproducible reflex micturition with bladder contraction and spasmodic rhythmic sphincter contractions was demonstrated. After the administration of suxamethonium reflex micturition occurred, but there was decreased bladder emptying as well as absence of spasmodic rhythmic sphincter contractions. The striated urethral sphincter would seen to play an important role in bladder emptying of decerebrated dogs.

Urethral Response to Nerve Stimulation Measured by Strain Gauge Force Transducer

This paper presents a study of urethral responses to efferent nerve stimulation in dogs. The pelvic, hypogastric and pudendal nerves were stimulated using a programmed instrument under three different in vivo conditions. The preparations consisted of: (A) bladder, urethra, and rectum; (B) urethra and rectum, and (C) urethra only. Stimulation of the pelvic nerve in preparation A resulted in elongation and constriction of the mid and proximal urethra with a resultant rise in pressure. However, this response was reduced in preparations B and C. Similar observations were made with hypogastric nerve stimulation. The results of pudendal nerve stimulation were significantly different, in that the pressure rise occurred in the mild and distal urethra and varied in elongation response.

Effects of autonomic agonists on in vivo female canine urethral motility.

The response of the urethra to intra-arterially administered autonomic agonists was studied in vivo by measuring the motility and pressure changes in female dogs. Phenylephrine produced shortening along the transverse axis with an increase in urethral pressure in a dose-dependent manner. Isoproterenol produced lengthening along the transverse axis with a decrease in urethral pressure. Both acetylcholine and dimethylphenylpiperazinium did not produce consistent patterns in urethral response. It seems that adrenergic drugs act predominantly on the circular muscle layer and cholinergic drugs act equally on both the circular and longitudinal muscle layers.

Application of ultrasonic M-mode scanning and computer evaluation on urodynamics.

The M-mode scanning images of urethra, detrusor pressure and urine flow rate during voiding were recorded together on the line scan recorder, and allowed for plotting and calculation of some valuable urodynamic parameters by computer evaluation. This procedure will permit first application of M-mode scanning and new direction on urodynamics.

Clinical evaluation of bicarbonate dialysis

重炭酸透析については, 最近いくつかの報告がなされており, 酢酸透析に比較し不快な症状の少ない透析ができる点で, その有効性が見直されている. 今回我々は, 透析時間を5時間から4時間に短縮し, 透析効果について5時間の酢酸透析と比較し検討を加えた.その結果, pH, HCO-3濃度, B. E. は, 4時間透析にもかかわらず酢酸透析に比較し透析後有意に上昇し, アシドーシスの改善効果が優れていた. 特にpHの改善が顕著で, 透析開始2時間で7,332±0.026から7.403±0.04まで上昇していた.尿素窒素, クレアチニン, 尿酸値は, 透析後有意に低下し, 除去率では, 5時間の酢酸透析と比較し劣らない結果を得た. 特にクレアチニンの除去率は, 酢酸透析の44.1±6.4%に比し, 重炭酸透析では, 52.7±4.4%と有意に高値を示した. また長期的にみた窒素代謝産物の透析前値の上昇, 及び体重の増加はまったく認められなかった. 透析ごとの体重減少量の比較では, 酢酸透析で2.0±0.4kg, 重炭酸透析で23±0.3kgと両者間に有意の差をみなかった. Ca濃度については, 透析後有意に上昇し, 低Ca血症は改善されていた.以上の所見より, 重炭酸透析では, 酸-塩基平衡の改善が効率よくしかも迅速であり, 透析中の不快な症状が少ないばかりでなく, 透析終了時まで十分な血液流量, 及び適正な限外濾過圧を維持することができ, 今後大面積-短時間透析において非常に有利であると判断した.