Plasma levels of 5-HT and 5-HIAA increased after intestinal ischemia/reperfusion in rats.
Intestinal ischemia/reperfusion (I/R) causes serious systemic injury, mainly from a variety of bioactive substances released from the injured intestine. To assess the possible roles of serotonin (5-hydroxytryptamine, 5-HT), a bioactive amine mainly stored in the intestine, in I/R injury, we assayed the levels of tryptophan, 5-HT, and 5-hydroxyindole acetic acid (5-HIAA) in the blood and intestine in a rat I/R model. Plasma 5-HT increased significantly over time after reperfusion; the plateau level was obtained 4 h after reperfusion and was associated with an increase in 5-HIAA. Plasma tryptophan levels declined gradually after reperfusion. The ratio of 5-HIAA/5-HT was significantly higher in I/R rats than in control rats, suggesting that elevated 5-HT was quickly metabolized in the systemic circulation. In the intestine, 5-HT decreased dramatically, whereas tryptophan increased. This phenomenon was prominent in the severely damaged intestine. These findings suggest that the injured intestine released large amounts of 5-HT, whereas its synthesis in the injured intestine was suppressed. An increase in 5-HT in the circulation may be related to various circulatory disturbances observed in humans after intestinal ischemia.
Teramoto
Y
Y
Department of Anesthesiology and Intensive Care, Hamamatsu University School of Medicine, Hamamatsu, 431-3192, Japan.
Urano
T
T
Nagai
N
N
Takada
Y
Y
Ikeda
K
K
Takada
A
A
D008735:5-Methoxytryptamine / Q000494:pharmacology; D000818:Animals; D004146:Dioxanes / Q000494:pharmacology; D004195:Disease Models, Animal; D006897:Hydroxyindoleacetic Acid / Q000097:blood*; D007422:Intestines / Q000098:blood supply* / Q000473:pathology; D054833:Isoindoles; D008297:Male; D010879:Piperazines / Q000494:pharmacology; D010880:Piperidines / Q000494:pharmacology; D011743:Pyrimidines / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000097:blood* / Q000209:etiology / Q000473:pathology; D012701:Serotonin / Q000097:blood*; D012702:Serotonin Antagonists / Q000494:pharmacology; D017366:Serotonin Receptor Agonists / Q000494:pharmacology
D004146:Dioxanes; D054833:Isoindoles; D010879:Piperazines; D010880:Piperidines; D011743:Pyrimidines; D012702:Serotonin Antagonists; D017366:Serotonin Receptor Agonists; C084858:SB 204070A; C055267:tandospirone; D012701:Serotonin; D008735:5-Methoxytryptamine; D006897:Hydroxyindoleacetic Acid