Selective effects of clofibrate on alkaline phosphatase isoenzymes in serum.

Administration of clofibrate to both hyperlipidaemic patients and normolipidaemic subjects produced a significant decrease, averaging 22%, in serum alkaline phosphatase activity. Quantitative isoenzyme analysis showed that this change was entirely attributable to an average reduction of 39% in the activity of liver alkaline phosphatase, and that no significant change in the bone isoenzyme occurred. An accompanying fall in serum gamma-glutamyltransferase activity was seen in some subjects but this change was not statistically significant in the group as a whole.