Objective: To observe the effects of Salvia miltiorrhiza (SM) on levels of neuropeptide Y1-36 and calcitonin gene-related peptide immune reactive substances (ir-NPY, ir-CGRP) in blood plasma and pons-oblongata after hypoxia-ischemic brain injury (HIBI) in neonatal rats.
Methods: Seven-day old rats were randomized into HIBI group (A), HIBI + SM group (B) and sham operation group(C). And each group was subdivided into 4 subgroups according to the different time after operation. 0.5 ml SM was injected intraperitoneally immediately and every 12 hrs afterwards. Changes of ir-NPY and ir-CGRP levels in plasma and pons-oblongata were observed immediately and 12, 24 and 48 hrs after HIBI by radioimmunoassay.
Results: Plasma levels of ir-NPY and ir-CGRP in different times after HIBI were all significantly raised but those in pons-oblongata were either raised or lowered to a certain degree. Part of the elevated ir-NPY could be reversed by SM injection.
Conclusion: Central and peripheral neuropeptide Y1-36 and calcitonin gene-related peptide take part in the pathophysiological process of HIBI, SM could partially reverse the abnormal post-HIBI elevation of ir-NPY, which may be one of the pathways of SM in promoting recovery of damaged brain function.