Histologic response to injected phosphatidylcholine in fat tissue: experimental study in a new rabbit model.

The application of phosphatidylcholine to the fat tissue of humans for aesthetic purposes has recently been in evidence, despite the sparse literature corroboration of this practice. The authors developed a new experimental model to study injection of substances in fat tissue in rabbits. The objective of this particular study was to verify the possible effects of phosphatidylcholine injected in the animals. The animal weight, the fat pad weight, the presence of inflammatory infiltrate, and fibrosis and necrosis at the application sites were observed. Two groups of rabbits received five weekly applications to the dorsal fat pad. The control group received saline solution 0.9%, and the study group received phosphatidylcholine. The removed fat tissue was evaluated 3, 7, 14, and 21 days after the fifth application was completed. The phosphatidylcholine group presented more intense inflammatory infiltrate and fibrosis than the control group (p = 0.05). Necrosis was not observed in any animal. There was no statistically significant difference with regard to the weights of the animal or the fat pad. On the basis of this study, the injection of phosphatidylcholine is relatively safe, but no effect was observed regarding the reduction of fat tissue volume. New studies with higher doses are needed to justify the clinical use of this substance.