Abstract
Abstract
Objectives – To quantify neurokinin 2 and 3 receptor mRNA from nine regions throughout the equine intestinal tract, and to evaluate the effect of jejunal ischemia/reperfusion and intraluminal obstruction on neurokinin 1, 2, and 3 receptor mRNA.
Methods – Specimens were harvested from 5 adult horses euthanized for reasons unrelated to gastrointestinal disease for the study of normal distribution of neurokinin receptor mRNA. Jejunal segments from 6 healthy adult horses subjected to intraluminal distension or ischemia/reperfusion injury were harvested to study the influence of inflammation on neurokinin 1, 2, and 3 receptor mRNA expression. RNA was isolated from normal tissues and also from tissues that underwent either a sham operation (control), 60 minutes of ischemia followed by 60 minutes of reperfusion (ISO), or 120 minutes of intraluminal distension (ILD) as part of an inflammatory model. RNA was reverse transcribed into cDNA. NK2 and NK3 primers were designed and mRNA was quantified using real-time PCR for all experimental groups.
Results – Expression of NK2 receptor mRNA was highest for the duodenum and the body of the cecum. NK3 mRNA expression had high variability. In the inflammatory model, no statistical significant difference was noted between treatment groups for NK1 or NK3 receptor mRNA. NK2 receptor mRNA expression was significantly decreased for ILD when compared to control.
Conclusions –The description of neurokinin receptor mRNA distribution throughout the equine intestinal tract is an important initial step towards determining potential clinical applications of tachykinin agonists and antagonists, as well as their role in gastrointestinal ischemia/reperfusion and intraluminal obstruction injury.