title: Does pharmacological activation of 5-HT1A receptors improve urine flow rate in female rats?
abstract: 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 sphincter-electromyography (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-HT1A receptors in controlling the UFR in female rats.
authors.affiliation: Department of Physical Medicine and Rehabilitation, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan; Department of Physical Medicine and Rehabilitation, Taipei Medical University Hospital, Taipei, Taiwan;
authors.forename: Shih-Ching
authors.initials: SC
authors.lastname: Chen
authors.affiliation: Department of Physical Therapy and Graduate Institute of Rehabilitation Science, College of Medicine, Chang Gung University, Taoyuan, Taiwan; Graduate Institute of Neural Regenerative Medicine, Taipei Medical University, Taipei, Taiwan; and Neuroscience Research Center, Chang Gung Memorial Hospital, Linkou Medical Center, Taoyuan, Taiwan.
authors.forename: Tsung-Hsun
authors.initials: TH
authors.lastname: Hsieh
authors.affiliation: Department of Physical Medicine and Rehabilitation, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan;
authors.forename: Wen-Jia
authors.initials: WJ
authors.lastname: Fan
authors.affiliation: Department of Physical Medicine and Rehabilitation, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan; Department of Physical Medicine and Rehabilitation, Taipei Medical University Hospital, Taipei, Taiwan;
authors.forename: Chien-Hung
authors.initials: CH
authors.lastname: Lai
authors.affiliation: School of Biomedical Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei, Taiwan; Graduate Institute of Biomedical Materials and Tissue Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei, Taiwan; Department of Physical Medicine and Rehabilitation, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan; Department of Physical Medicine and Rehabilitation, Taipei Medical University Hospital, Taipei, Taiwan; cwpeng@tmu.edu.tw.
authors.forename: Chih-Wei
authors.initials: CW
authors.lastname: Peng
mesh_terms: D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000494:pharmacology; D000818:Animals; D003714:Denervation; D004576:Electromyography; D005260:Female; D007001:Hypogastric Plexus / Q000502:physiology; D009466:Neuromuscular Blocking Agents / Q000494:pharmacology; D010879:Piperazines / Q000494:pharmacology; D011725:Pyridines / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D044282:Receptor, Serotonin, 5-HT1A / Q000187:drug effects*; D058825:Serotonin 5-HT1 Receptor Agonists / Q000627:therapeutic use*; D058829:Serotonin 5-HT1 Receptor Antagonists / Q000494:pharmacology; D012702:Serotonin Antagonists / Q000494:pharmacology; D014521:Urethra / Q000503:physiopathology; D014554:Urination / Q000187:drug effects; D014563:Urodynamics / Q000187:drug effects*
chemical_list: D009466:Neuromuscular Blocking Agents; D010879:Piperazines; D011725:Pyridines; D058825:Serotonin 5-HT1 Receptor Agonists; D058829:Serotonin 5-HT1 Receptor Antagonists; D012702:Serotonin Antagonists; D044282:Receptor, Serotonin, 5-HT1A; C090413:N-(2-(4-(2-methoxyphenyl)-1-piperazinyl)ethyl)-N-(2-pyridinyl)cyclohexanecarboxamide; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin
keywords: 8-OH-DPAT; EUS-EMG; WAY-100635; intravesical pressure; neuromuscular blockade