Quantitative Analysis of Secreted Catecholamines from Chromaffin Cellsin Vitroandin Vivo

Abstract

Background: Adrenal medullary transplants into the subarachnoid space have been demonstrated to reduce pain sensitivity. This analgesia most likely results from the release of neuroactive substances, particularly catecholamines and opioid peptides from the transplanted cells into spinal cord. Methods: Isolated bovine chromaffin cells were encapsulated with alginate and poly-L-lysine prior to implantation into rat´s subarachnoid space to protect them from host immune system. And then catecholamines from encapsulated chromaffin cells were measured quantitatively in vitro by High Performance Liquid Chromatograph. The animals were randomized into 2 groups, one of which received microencapsulated chromaffin cells and the other empty capsules. The effects of such implants were evaluated on the pain behavior resulting from a chronic constriction injury of the rat sciatic nerve for 30 days. Results: Catecholamine concentration in cerebrospinal fluid (CSF) was analyzed. Data (mean SD) are considered significant at P