Acupuncture needles were inserted and artificially broken in subcutaneous and muscle tissues in rats. Movement of the needles in the body and histo-pathological changes thus induced were studied in this experiment.
The needles moved in the body most often within 2 weeks of the beginning of experiments. The movement was observed more frequently in the needles buried in the foreleg than in other parts of the body. It was supposed that the movement was related to the motility of this part. The thin or short gold needles moved least of all. In contrast, stainless steel needles moved more actively, sometimes being found in the internal organs, such as the liver, testicles, heart and spermatic duct. Most of the needles remaining in the body were encapsulated in connective tissues after several weeks.
General implications of the buried needles for a organism were discussed from the histopathological point of view.