Abstract: A series of 8-phenyl-isoquinoline derivatives (I) exhibit high binding affinity to 5-HT7 receptor (5-HT7R) and demonstrate potent antinociceptive activity in two animal models for Irritable Bowel Syndrome (IBS) by intraperitoneal injection (i.p.) or by oral administration (p.o.). These 5-HT7 receptor antagonists are a new class of therapeutic agents for the treatment of IBS.

Abstract: A series of 8-phenyl-isoquinoline derivatives (I) exhibit high binding affinity to 5-HT7 receptor (5-HT7R) and demonstrate potent antinociceptive activity in two animal models for Irritable Bowel Syndrome (IBS) by intraperitoneal injection (i.p.) or by oral administration (p.o.). These 5-HT7 receptor antagonists are a new class of therapeutic agents for the treatment of IBS.

Abstract: A system for detecting function of an intestinal barrier in a subject is provided, which includes: a contrast agent for being administered directly to an intestinal lumen of the subject, allowing a detecting device to detect in vivo or in vitro the signal indication produced by the contrast agent in the tested targets such as abdominal organs or a blood sample; and a determining device for determining intensity of the signal indication produced by the contrast agent in the tested targets after the administration of the contrast agent so as for the intensity of the signal indication after the administration of the contrast agent to indicate damage of the intestinal barrier in the subject. The present invention also provides a method of detecting function of the intestinal barrier in a subject by using the system of the present invention.