Cystometric and External Urethral Sphincter Measurements in Awake Rats with Implanted Catheter and Electrodes Allowing for Repeated Measurements

Summary

This protocol first describes the surgical procedure of the permanent implantation of a urinary bladder catheter combined with external urethral sphincter electrodes, and second, the measurement of the function of the urinary bladder and external urethral sphincter in implanted awake animals.

Abstract

Lower urinary tract function is mainly assessed by means of cystometric bladder function analysis in rodents. Conventional cystometries are usually performed as terminal analysis under urethane anesthesia. It is well known that anesthetic drugs can influence bladder function. Hence, the aim of this technique is to perform cystometric measurements of the urinary bladder and external urethral sphincter in lightly restrained awake rats. For this purpose, a bladder catheter is implanted into the bladder dome. Subsequently, two electrodes are implanted bilateral to the external urethral sphincter and a ground electrode is sutured to a non-responsive skeletal muscle. The bladder catheter and the three electrodes are finally tunneled subcutaneously to the neck region and affixed to a harness. With this technique, the lower urinary tract can be measured at multiple time points in the same animal to assess lower urinary tract function. The main application of this technique is the follow-up of simultaneous urinary bladder and external urethral sphincter function in awake healthy rats and after induction of a disease or injury. Moreover, subsequent lower urinary tract monitoring can be performed during evaluation of the disease/injury and to monitor treatment efficacy.

Introduction

To analyze urinary storage and voiding function and dysfunction, most studies have used rodent models. Through sequential activation of reflexes, micturition is produced. The coordination of these reflexes is essential for efficient voiding¹. Cystometric recording techniques provide valuable tools for analyzing the urinary bladder function under its neural control¹.

Most conventional cystometries in rats are done as a single, final analysis in anesthesia, mainly urethane², and focus on the urinary bladder solely. However, in some pathologies like neurogenic lower urinar....

Protocol

All procedures described here were approved by the Austrian Governmental Ethics committee for animal research (Bundesministerium für Wissenschaft, Forschung und Wirtschaft, WF / V /3b) and were in compliance with the Association for Assessment of Laboratory Animal Care guidelines for animal use. Rats used for this approach were female, 12-week-old Lewis rats. Use sterile instruments throughout the protocol.

1. Material Preparation

1. Manufacturing of the Catheter
   1. Cut the catheter (polyethylene tubing PE-50) in appropriate length (20 to 25 cm) to fit the size of the animal.
      NOTE: Leave some ....

Results

A schematic showing the process of awake cystometric measurements is presented in Figure 1 and the internal anatomy for bladder catheter implantation is shown in Figure 2. Surgery takes about 2 h. Postoperative analgesia and antibiotics, as described in the protocol, cover pain and infections over five days after surgery. No signs of any pain were noticed thereafter. Twice daily careful inspection of the abdomen, abdominal suture.......

Discussion

This protocol describes the surgical procedure of a permanent catheter and urethral sphincter electrodes implantation and the cystometric recording technique in awake, lightly restrained rats including both the simultaneous analysis of the urinary bladder and external urethral sphincter.

Critical steps during surgery are the careful implantation of the bladder catheter, avoiding leakage and extensive manipulation. Moreover, a precise implantation of the electrodes bilateral to the urethral ext.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Polyethylene tubing PE 50	Becton Dickinson	427411	Catheter
Prolene 6-0 (BV-1, 9.3 mm, 3/8c)	Ethicon	EH7403H	Suture
Teflon coated steel wire	Cooner wire	AS631	Electrode material
Silver wire 0.250 mm	World Precision Instruments	AGW1030	Electrode material
Rotilabo - PVC tube	Carl Roth	97241	Harness
Vicryl rapide 4-0 (P-3, 13 mm, 3/8c)	Ethicon	V4940H	Suture
Quick Connect Single Harness	SAI Infusion Technologies	QCH-23CW	Harness
Shrinking tubes	ChiliTec	17894	Electrode soldering
Soldering wire Pb60 Sn40	Stannol	LD0029	Electrode soldering
Fluxing agent 157	Castolin Eutectin	157 0150	Electrode soldering
Conn Unshrouded Header HDR 3 POS, 2.54mm Solder ST Thru-Hole Box	Preci-dip	801-87-050-10-001101	Electrode soldering
Conn Socket Strip SKT 50 POS 2.54mm, Solder ST Thru-Hole Box	Preci-dip	890-18-003-10-001101	Electrode soldering
Rat Cystometry Package (contains pump, scale, pressure transducer, hardware for cystometric analysis)	Catamount Research and Development Inc.	CAT-CYT-R
Differential amplifier with active headstage	AD instruments	DP-311	EMG amplifier
Restrainer Medium size for rats 200-300 g	emka Technologies	HLD-RM
Uro Dyn Software	Zürich of University		MTA-based
Female rats (Strain Lewis) 12 weeks of age	Charles River, Sulzfeld, Germany		animals