We investigated whether calcitonin gene-related peptide (CGRP) was able to affect the production of collagen and glycosaminoglycans (GAG) in cultures of rat fat-storing cells (FSC). Rat CGRP (1 nM-1 microM) induced a dose-dependent increase of total GAG production in FSC cultures with an EC50 of 28 nM. One uM human CGRP (8-37) shifted the dose-response curve of rat CGRP to the right (EC50 = 257 nM) without depressing the maximal response. Salmon calcitonin (1 nM-1 microM) did not significantly modify total GAG accumulation in FSC cultures. Collagen type I and III production was not significantly affected by either CGRP or calcitonin in FSC cultures. These findings suggest that peripheral sensory neuropeptides may modulate liver fibrogenesis.