The role of sensory C-fibers in response of vagal afferent stimulation by gastric distension in rats with experimental chronic gastric ulcer.
There is growing evidence that gastric vagal afferent input may contribute to the altered sensations associated with gastrointestinal disorders. The aim of our study was to evaluate gastric vagal afferents (VA) activity in rats with experimental gastric ulcer and ulcer healing. The study was carried out on rats with gastric ulcer (GU), including, a group with perivagal capsaicin pretreatment (CAP), a group with capsaicin administration in gastric ulcer (CAP+GU) animals and control rats. In all rats electrical VA activity was recorded and analysed. In GU rats recordings were carried out in chronic ulcer and ulcer healing. In GU and CAP+GU groups gastric balloon distensions with vagal recording was performed on 3(rd) day after ulcer induction. Usually, experimental GU healed spontaneously within 2 weeks. Three days after acetic acid application when GU fully develop, the frequency of the basal VA activity was almost 3-times higher than in the control intact rats and remained elevayed until 4(th) week after ulcer induction. VA response to gastric distension increased concomitantly with increased balloon volume in both GU and control animals, but it was several times higher in GU rats. Perivagal capsaicin application decreased the frequency of spontaneous VA activity and decreased the response of VA to gastric distension. In CAP+GU, spontaneous activity as well as the response to gastric distension were higher than in CAP rats. Our study shows that GU induced inflammatory changes increase sensitivity of gastric VA. Capsaicin-sensitive vagal afferent fibers may play some role in this phenomenon. Peripheral sensitization of VA persists even when gastric ulcer is completely healed.
Zurowski
D
D
Department of Pathophysiology Jagiellonian University Medical College, Krakow, Poland. danski@mp.pl
Dobrek
Ł
Ł
Bugajski
A
A
Thor
P J
PJ
D019342:Acetic Acid; D000344:Afferent Pathways / Q000503:physiopathology*; D000818:Animals; D002211:Capsaicin / Q000494:pharmacology; D002908:Chronic Disease; D004195:Disease Models, Animal; D015905:Gastric Balloon; D013271:Gastric Dilatation; D008297:Male; D009475:Neurons, Afferent / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D013276:Stomach Ulcer / Q000139:chemically induced* / Q000473:pathology / Q000503:physiopathology*; D014630:Vagus Nerve / Q000503:physiopathology*
D019342:Acetic Acid; D002211:Capsaicin