Influence of serotonergic mechanisms on the urine flow rate in male rats

Fan, Wei; Chen, Shih Ching; Hsieh, Tsung Hsun; Lai, Chien Hung; Lin, Yun‐Sheng; Peng, Chih Wei; Kou, Yu Ru

doi:10.1152/ajpregu.00160.2014

Cited by 8 publications

(15 citation statements)

References 38 publications

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“…The surgical procedure for the recordings was performed as previously reported [12,14]. The femoral vein was catheterized for fluid infusion, and the body temperature was maintained at 36-38°C by using a recirculating water blanket.…”

Section: Simultaneous Recording Of Ivp Eus-emg and Ufrmentioning

confidence: 99%

Chronic pudendal neuromodulation using an implantable microstimulator improves voiding function in diabetic rats

et al. 2016

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Abtract Objective. Few studies have investigated the feasibility of using chronic pudendal neuromodulation for improving voiding function in patients with diabetes who are also experiencing urinary retention. The present study investigated the effects of chronic electrical stimulation (ES) of the sensory branch of the pudendal nerve on voiding function in diabetic rats. Approach. A custom-made implantable microstimulation system was designed and manufactured for chronic implantation in normal control (NC) and diabetic rats. After three or six weeks of pudendal neuromodulation, the intravesical pressure, external urethral sphincter electromyograms (EUS-EMGs), and urine flow rate (UFR) of all rats were simultaneously recorded to assess the effects of chronic pudendal ES on voiding function. Morphological changes in pudendal axons were assessed through hematoxylin and eosin (H&E) staining. Results. Abnormal cystometric measurements, including an increased volume threshold, contraction amplitude, and residual volume (RV) as well as a decreased burst period (BP) indicated voiding dysfunction in the diabetic rats with sham ES for three or six weeks. However, real ES for three or six weeks reversed these abnormal results; these parameters became similar to those of the NC rats and, consequently, voiding efficiency (VE) increased significantly from 17%–45% to 51%–57%. The cross-sectional area and axonal density of the pudendal nerve decreased in all the diabetic rats with sham ES for six weeks; however, these values increased significantly after real ES for six weeks. Significance. This study demonstrated the feasibility of using chronic pudendal neuromodulation for improving voiding function in diabetic rats. These results may facilitate the development of an advanced neural prosthesis for restoring bladder function in clinical settings.

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Section: Simultaneous Recording Of Ivp Eus-emg and Ufrmentioning

confidence: 99%

Chronic pudendal neuromodulation using an implantable microstimulator improves voiding function in diabetic rats

et al. 2016

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“…In the absence of direct measurements of voiding flow, an estimate of mean VFR can be obtained using several methods (8), including dividing VV by the duration of voiding represented by either: 1) bladder CD, 2) the TSP of the EUS EMG, or 3) the period of EUS bursting (BD). Recent experiments by Fan et al (9) in which urethral flow was directly monitored with a flow meter attached to the urethra in anesthetized male Sprague-Dawley rats revealed that voiding occurs during the period of EUS bursting. Thus VFR in the present experiments was estimated by dividing the VV by duration of voiding measured indirectly by duration of EUS bursting (BD).…”

Section: Methodsmentioning

confidence: 99%

Effect of orchiectomy and testosterone replacement on lower urinary tract function in anesthetized rats

Cheng

Groat

2016

American Journal of Physiology-Renal Physiology

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Lower urinary tract (LUT) symptoms (LUTS), including frequency, urgency, incomplete voiding, and slow stream, are common in both men and women with advancing age. The most common cause for LUTS in aging men is benign prostatic hyperplasia. Some studies have also revealed an inverse association of serum testosterone levels with LUTS; however, the underlying mechanisms by which gonadal hormones affect the LUT have not been clarified. In the present study, we examined the effect of orchiectomy and testosterone replacement on LUT function in adult male Sprague-Dawley rats. Six weeks after bilateral orchiectomy or sham operations and 3 wk after injection of long-acting testosterone undecanoate (100 mg/kg im), transvesical cystometry and external urethral sphincter electromyogram (EUS EMG) recordings were performed under urethane anesthesia. The micturition reflex was elicited in both sham and orchiectomized animals. In orchiectomized rats, volume threshold for inducing micturition decreased by 47.6%; however, contraction amplitude, duration, and voiding efficiency were similar in sham and orchiectomized rats. The active period during EUS EMG bursting was lengthened during micturition in orchiectomized animals. Testosterone treatment, which normalized plasma testosterone levels, reversed these changes but also increased the duration of EUS EMG bursting. Orchiectomy also reduced mean voiding flow rate estimated from the duration of EUS EMG bursting, an effect that was not reversed by testosterone. The results indicate that orchiectomy affects both the active and passive properties of the bladder and urethra, and that many, but not all, of the changes can be reversed by testosterone.

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“…Our recent study indicated that the 5-HT 1A agonist 8-OH-DPAT significantly reduced the UFR during voiding in male rats (13). Furthermore, recent studies have demonstrated that 8-OH-DPAT increases urethral pressure (resistance) during the voiding reflex in male rats; however, it significantly reduces the pressure in female rats (14).…”

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confidence: 89%

“…An ultrasonic flow probe (ME2PXN, Transonic Systems, Ithaca, NY) connected to a flowmeter (TS410, Transonic Systems) was used for UFR measurements. The flow probe was placed around the most distal part of the urethra (13,29,33).…”

Section: General Preparationsmentioning

confidence: 99%

“…The following IVP parameters were measured as previously reported (4,22,27), as follows: 1) volume threshold: the minimally sufficient volume of infused saline for inducing the first voiding contraction; 2) pressure threshold: the pressure required to induce voiding contractions; 3) contraction amplitude: the maximal pressure during voiding; 4) contraction duration: the duration of the bladder contraction during voiding; 5) contraction area: the area of the bladder contraction under the bladder pressure curve; 6) voided volume: the micturition volume threshold subtracted by the residual volume; 7) residual volume: the volume of saline withdrawn through the intravesical catheter after voiding; and 8) voiding efficiency: the ratio of the voided volume to the micturition volume threshold. In addition, three EUS-EMG parameters were measured as described elsewhere (13,22,26): the burst, silent, and active periods, as shown in Fig. 1.…”

Section: Physiological Investigationsmentioning

confidence: 99%

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Does pharmacological activation of 5-HT_1A receptors improve urine flow rate in female rats?

Chen

Hsieh

Fan

et al. 2016

American Journal of Physiology-Renal Physiology

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Chen SC, Hsieh TH, Fan WJ, Lai CH, Peng CW. Does pharmacological activation of 5-HT1A receptors improve urine flow rate in female rats? Am J Physiol Renal Physiol 311: F166 -F175, 2016. First published May 4, 2016 doi:10.1152/ajprenal.00469.2015.-The role of 5-HT1A receptors in regulating voiding functions remains unclear, particularly regarding the urine flow rate (UFR) during voiding. This study examined the effects of 5-HT1A receptors on regulating urethral functions in female rats and investigated underlying modulatory mechanisms. Intravesical pressure (IVP), external urethral sphincterelectromyography (EUS-EMG), and UFR were simultaneously recorded during continuous transvesical infusion to examine the effects of a 5-HT1A receptor agonist (8-OH-DPAT) and antagonist (WAY-100635) on bladder and urethral functions. In addition, this study evaluated the independent roles of urethral striated and smooth muscles in the UFR in rats after a neuromuscular blockade (NMB) treatment and bilateral hypogastric nerve transection. Our results revealed that 8-OH-DPAT significantly increased the maximal UFR but reduced the mean UFR. This discrepancy may be because 8-OH-DPAT markedly increased the maximal UFR during the initial segment of the flow duration and subsequently induced an approximately zero level of long oscillatory waves during the remaining flow duration. Thus the mean UFR was reduced because of the prolonged approximately zero level of the UFR. However, paralyzing the EUS with an NMB agent, 8-OH-DPAT, significantly increased the maximal and mean UFRs because the prolonged zero level of the oscillatory UFR did not continue. These results support the hypothesis that the increased UFR in female rats during voiding is due to the induction of urethral smooth muscle relaxation by 8-OH-DPAT. This paper provides a detailed understanding of the role of 5-HT 1A receptors in controlling the UFR in female rats. intravesical pressure; EUS-EMG; 8-OH-DPAT; WAY-100635; neuromuscular blockade THE PRIMARY FUNCTIONS OF THE lower urinary tract (LUT) are storage and periodic urine elimination. These functions require reciprocal coordination between the urinary bladder and urethra outlets, including the bladder neck, urethra, and external urethral sphincter (EUS). The urethra consists of smooth and striated muscle layers that are regulated by the following three peripheral nerve sets: sacral parasympathetic (pelvic nerves) and thoracolumbar sympathetic nerves (hypogastric nerves) that innervate urethral smooth muscles, and sacral somatic nerves (pudendal nerves) that innervate urethral striated muscles including the EUS and pelvic floor muscles.Receptors for serotonin [5-hydroxytryptamine (5-HT)] comprise 14 structurally different 5-HT receptors in mammalian species, including 7 subfamilies (5-HT 1 -5-HT 7 ) (28). Pharmacological studies in animals have indicated that the three sets of LUT nerve terminals contain numerous 5-HT receptor subfamilies. Specifically, 5-HT 1A receptors are vital to LUT functions (32). The effects of 5-HT...

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Influence of serotonergic mechanisms on the urine flow rate in male rats

Cited by 8 publications

References 38 publications

Chronic pudendal neuromodulation using an implantable microstimulator improves voiding function in diabetic rats

Chronic pudendal neuromodulation using an implantable microstimulator improves voiding function in diabetic rats

Effect of orchiectomy and testosterone replacement on lower urinary tract function in anesthetized rats

Does pharmacological activation of 5-HT_1A receptors improve urine flow rate in female rats?

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