Pharmacological actions of leukotrienes C4, D4 and E4 on guinea pig isolated taenia caecum as a preparation to study leukotrienes.

The contractile effects of leukotrienes (LTs) C4, D4 and E4 were studied in guinea pigs isolated taenia caecum. LTs C4, D4 and E4 contracted taenia caecum at low concentrations in a concentration-dependent manner. The response to LTs was not influenced by a gamma-glutamyl transpeptidase inhibitor (L-serine borate), aminopeptidase inhibitor (L-cysteine) or cyclooxygenase inhibitor (flurbiprofen), suggesting that LTC4 and LTD4 were not metabolized or metabolized only slightly in the guinea pig isolated taenia caecum, and that each of the LTs showed the direct contractile action. Furthermore, FPL55712 antagonized the response to LTD4 and LTC4 competitively but not that to LTE4. These results suggested that the guinea pig isolated taenia caecum is useful preparation to study the pharmacological actions of LTs.