Assessment of visceral sensitivity using radio telemetry in a rat model of maternal separation.
Stress plays an important role in the development of visceral hypersensitivity, a key mechanism underlying the pathophysiology of the irritable bowel syndrome. Visceral sensitivity in rats is generally assessed under restrain conditions. To avoid this potential stress factor, we developed a model using implanted radio telemetry for remote measurement of the visceromotor response (VMR) to colorectal distention (CRD). Ten days after implantation of a radio telemetry transmitter and EMG electrodes, visceral sensitivity was evaluated by applying a standardized distension protocol (1, 1.5 and 2 mL) on three different days. In a second series, visceral sensitivity was assessed in maternally separated rats before, directly after and at 6 and 24 h after water avoidance (WA) stress. CRD resulted in a reproducible VMR response on the three different study days. In separated but not in non-handled rats, WA significantly increased visceral sensitivity at 6 h (P=0.006) and 24 h (P=0.004) after WA. Our results show that radio telemetry is a reliable and well tolerated new tool for evaluating visceral sensitivity in rats. These data further confirm that maternal separation is a good model for evaluating the mechanisms underlying visceral hypersensitivity.
Welting
O
O
Department of Gastroenterology and Hepatology, Academic Medical Center, Amsterdam, The Netherlands.
Van Den Wijngaard
R M
RM
De Jonge
W J
WJ
Holman
R
R
Boeckxstaens
G E
GE
D000009:Abdominal Muscles / Q000502:physiology*; D000818:Animals; D001010:Anxiety, Separation / Q000523:psychology*; D001835:Body Weight / Q000502:physiology; D002404:Catheterization; D004567:Electrodes, Implanted; D004576:Electromyography; D004594:Electrophysiology; D005260:Female; D006234:Handling, Psychological; D008426:Maternal Deprivation; D009119:Muscle Contraction / Q000502:physiology; D051381:Rats; D020318:Rats, Long-Evans; D012007:Rectum / Q000502:physiology; D013315:Stress, Psychological / Q000503:physiopathology; D013686:Telemetry