Uptake of thymidine labeled on carbon 2: a potential index of liver regeneration by positron emission tomography.

Noninvasive measurement of liver regeneration with positron emission tomography has been attempted with 11C-thymidine; however, results were unsatisfactory using thymidine labeled on its methyl group. To evaluate whether the specificity of the method could be improved by modifying the labeling position of the tracer, thymidine labeled on its methyl group with 3H and thymidine labeled on its carbon 2 with 14C were injected in 22 hepatectomized rats either 1 hr (when DNA synthesis is not increased) or 24 hr after the surgical procedure (when the rate of DNA synthesis is maximal). Liver samples taken 10, 30 and 120 min after injection showed that, in contrast to 3H-radioactivity, 14C-radioactivity measured in whole tissue allowed a clear discrimination between regenerating and nonregenerating livers. In addition, 14C-radioactivity measured in whole tissue of regenerating livers correlated with the DNA radioactivity 10, 30 and 120 min after injection of the tracer. In contrast, no such correlation was found with the methyl-labeled thymidine. Analysis of the radioactive material present in the non-DNA fraction using ion exchange disks and high-performance liquid chromatography showed that 2-C-labeled thymidine was incorporated into DNA without accumulation of labeled metabolites whereas, for the methyl-labeled thymidine, almost all radioactivity was related to degradative products. Therefore the evaluation of the liver regeneration with the 2-C-labeled thymidine, which does not require cellular fractionation, should be suited for noninvasive measurement with positron emission tomography.

Manometric study of the activity of alizapride on the motor function of the human sphincter of Oddi.

Alizapride is a potent antiemetic, acting as a dopamine receptor antagonist on the chemoreceptor trigger zone with few gastrokinetic properties. Little is known of its activity on the human sphincter of Oddi (SO). The aim of this study was to assess the effect of alizapride on SO motor function and to evaluate a possible use of alizapride in premedication for endoscopy of the upper digestive tract. We selected ten patients who underwent retrograde cholangiopancreaticography, but had no evidence of biliary or pancreatic disease. Endoscopic manometry was applied before and for 10 min after administration of alizapride 100 mg i.v. No significant modification of basal pressure or phasic activity was observed. Alizapride can be proposed as an antiemetic in patients with biliary disorders.