title: Elevation of colony stimulating factors in mouse serum after injection of PSK, an antitumor polysaccharide.
abstract: The level of colony stimulating factors (CSF) in mouse serum was elevated by a single intraperitoneal injection of PSK, a host-mediated antitumor protein-bound polysaccharide obtained from Basidiomycetes. The assay for CSF activity was performed by employing a semisolid methylcellulose culture method using mouse bone marrow cells, and the activity was estimated by an equation well matched with the dose response curve obtained in the CSF assay. A temporary increase of CSF activity within 10 h after the injection of an antitumor polysaccharide, Krestin (PSK) (250-1000 mg/kg) was followed by a fast decline in the activity, but no significant increases were detected in the cases of 62.5 and 125 mg/kg PSK injections. The CSF activity in PSK (500 mg/kg)-treated mouse serum was separated into two active fractions by DEAE ion-exchange chromatography, and both fractions were found to induce colonies comprised of cells with the properties of macrophage in regard to morphology, cytochemistry of non-specific esterase, phagocytic function and expression of Fc receptors on the cell surface. The elevation of the serum CSF level due to administration of so-called host-mediated antitumor agents might be one of the tumor-defense mechanisms in vivo.
mesh_terms: D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000494:pharmacology*; D001853:Bone Marrow / Q000032:analysis; D002478:Cells, Cultured; D002852:Chromatography, Ion Exchange; D003115:Colony-Stimulating Factors / Q000032:analysis / Q000097:blood*; D005260:Female; D051379:Mice; D008815:Mice, Inbred Strains; D011509:Proteoglycans / Q000494:pharmacology*
chemical_list: D000903:Antibiotics, Antineoplastic; D003115:Colony-Stimulating Factors; D011509:Proteoglycans; C010770:polysaccharide-K