Nerve growth factor increases substance P, cholecystokinin and vasoactive intestinal polypeptide immunoreactivities in primary sensory neurones of newborn rats.

Immunoreactive substance P, somatostatin, gastrin/cholecystokinin and vasoactive intestinal polypeptide were studied in lumbar dorsal root ganglia of 14-day-old rats treated from day 2 to 11 of life with nerve growth factor. Increased staining intensity of neuronal cell bodies and processes for substance P, gastrin/cholecystokinin and vasoactive intestinal polypeptide was observed by immunohistochemistry indicating increased neuronal peptide concentrations. These results were supported by radioimmunoassays showing increased ganglionic levels of substance P and vasoactive intestinal polypeptide. Both techniques, however, failed to show a significant increase of somatostatin levels.