| Abstract: | Hepatocytes were isolated from livers of adult male SpragueDawley rats and cultured
in Williams'E Medium with 3 H thymidine. The effect of 5hydroxytryptamine (5HT) was
investigated through adding various concentrations (10-810-3 mol/L) of 5HT to the hepatocyte
cultures in the presence or absence of epidermal growth factor (EGF) and insulin. The
involvement of 5HT2 receptor was examined by adding a 5HT2 receptor antagonist, ketanserin
(10-6 mol/L), to some of the cultures containing 5HT. The increment of DNA synthesis was
measured by 3 H thymidine incorporation. The results showed that 5HT2 (10-6 mol/L)
significantly (P<005) increased the amount of DNA synthesis induced by EGF and insulin in the
cultured adult rat hepaptocytes. The effect of 5HT in enhancing DNA synthesis began to appear
at a concentration between 10-7 and 10-6 mol/L and reached maximum at concentrations of 10-4
mol/L. The enhancement of DNA synthesis by 5HT was significantly (P<005) antagonized by
ketanserin, suggesting that this effect of 5HT was mediated by 5HT2 receptor subtype. |
