Altered neuroendocrine response and gastric dysmotility in the Flinders Sensitive Line rat

In the search for animal models that can replicate some features of functional dyspepsia (FD) patients, we turned our interest to the Flinders Sensitive Line (FSL) rat. Gastric motility disturbances prevalent in FD patients as well as urine corticosterone and plasma prolactin were measured following buspirone challenge. Flinders Resistant Line (FRL) rat was used as control. The results show that the FSL rats have a disturbed gastric motility, reflected as both an increased gastric accommodation rate and gastric volume during gastric distension as well as a delayed gastric emptying, the latter possibly as a consequence of the former. Lipid administration resulted in a significant increase in maximal gastric volume only in the FRL rats. Both the corticosterone response to buspirone and the 24-h urinary output of corticosterone were normal in FSL rats. Similar to FD patients, the FSL rat showed supersensitivity to buspirone in the increase in prolactin release. Although FSL rats show some features similar to a subset of FD patients, the increased gastric accommodation contrasts to the reduced accommodation often seen in FD patients. Further studies are warranted to determine the relevance of this rat strain as a model for FD.