Impaired micturition reflex caused by acute selective dorsal or ventral root(s) rhizotomy in anesthetized rats.
OBJECTIVE
To clarify the contributions of parasympathetic inputs and outputs to the micturition reflex.


METHODS
Intra-vesical pressure (IVP), external urethral sphincter electromyogram (EMG), pelvic afferent nerve activities (PANA), and pelvic efferent nerve activities (PENA) as well as the time-derived IVP (dIVP, an index of bladder contractility) were evaluated in intact and acute dorsal or ventral root(s) rhizotomized (DRX and VRX, respectively) rats.


RESULTS
In DRX rats, when compared with that in intact stage, the voiding frequency was decreased (75 +/- 15% of intact, P < 0.05, n = 8), while the threshold pressure to trigger voiding contractions was significantly increased (187 +/- 75% of intact, P < 0.05, n = 8). In addition, several insufficient contractions (5.3 +/- 3.5 contractions/voiding, P < 0.05, n = 8) occurred in ahead of each voiding contraction. On the other hand, in VRX rats, the peak and rebound IVP were significantly decreased (90 +/- 3.5% and 75 +/- 11.3% of intact, P < 0.01, n = 8), while the threshold pressure was not affected (102 +/- 11% of intact, P = NS, n = 8). The time-derived parameters were significantly decreased in VRX (peak dIVP, 78 +/- 10.2%, rebound dIVP, 75 +/- 15.6%, minimal dIVP, 68 +/- 14% of intact, P < 0.01, n = 8) but only peak dIVP was decreased (85 +/- 11% of intact, P < 0.01, n = 8) in DRX rats.


CONCLUSIONS
Acute selective DRX and VRX rat can be an animal model to investigate peripheral neural control in micturition functions.
Department of Physiology, College of Medicine, Chung-Shan Medical University, Taichung, Taiwan.
Jiuan-Miaw
JM
Liao
Department of Surgery, Division of Urology, Taichung Veterans General Hospital, Taichung, Taiwan.
Chen-Li
CL
Cheng
School of Physical Therapy, College of Medicine, Chung-Shan Medical University, Taichung, Taiwan.
Shin-Da
SD
Lee
Department of Obstetrics and Gynecology, Hospital, Chung-Shan Medical University, Taichung, Taiwan.
Gin-Den
GD
Chen
Department of Physiology, College of Medicine, Chung-Shan Medical University, Taichung, Taiwan.
Kuo-Jung
KJ
Chen
Department of Cosmetic Science, Providence University, Taichung, Taiwan.
Chao-Hsun
CH
Yang
Department of Biotechnology, Ming-Chuan University, Taoyuan, Taiwan.
Shwu-Fen
SF
Pan
Department of Applied Cosmetic, Ching-Kuo Institute of Management and Health, Keelong, Taiwan.
Mei-Jung
MJ
Chen
School of Medicine, Kao-Hsiung Medical University, Kaohsiung, Taiwan.
Pei-Chen
PC
Huang
Department of Physiology, College of Medicine, Chung-Shan Medical University, Taichung, Taiwan.
Tzer-Bin
TB
Lin
D000758:Anesthesia; D000818:Animals; D005260:Female; D010275:Parasympathetic Nervous System / Q000503:physiopathology; D011312:Pressure; D051381:Rats; D017208:Rats, Wistar; D012021:Reflex, Abnormal; D019051:Rhizotomy / Q000009:adverse effects* / Q000379:methods*; D001743:Urinary Bladder / Q000503:physiopathology*; D014554:Urination / Q000502:physiology*