Macrophages within the granulomas of murine Schistosoma mansoni are a source of a somatostatin 1-14-like molecule.

Inflammatory cells secrete some neuropeptides that function as immunomodulators. Somatostatin has immunoregulatory properties. It is unknown whether immune cells make somatostatin. Intricate intercellular communications govern the granulomas of murine Schistosoma mansoni. These granulomas synthesize several neuropeptides. Thus, it was determined whether somatostatin is in these inflammatory lesions. Granulomas, which were isolated from the livers of infected mice, contained somatostatin 1-14 as shown by radioimmunoassay and chromatography. Immunostaining localized immunoreactive somatostatin and pre-prosomatostatin to granuloma macrophages. Granuloma macrophages cultured in vitro released immunoreactive somatostatin. Calcium ionophore A23187, which promotes macrophage secretion, increased somatostatin in the culture supernatants. Thus, the granulomas have a molecule with somatostatin 1-14-like properties that is possibly a secretory product of the granuloma macrophage.