SUBMANDIBULAR-GLAND PEPTIDE-T (SGP-T) - MODULATION OF ENDOTOXIC AND ANAPHYLACTIC SHOCK

This report summarizes recent studies on the antishock activities of a novel peptide, submandibular gland peptide-T (SCP-T). This heptapepti de (TDIFEGG) was isolated from the submandibular glands of rats based an the ability of extracts of these glands to reduce the severity of t he hypotension induced by lipopolysaccharide. SGP-T was also found to reduce the severity of anaphylactic shock in ovalbumin-sensitized rats . Structure-activity relationship studies revealed that the inhibition of intestinal anaphylaxis in vitro only required a portion of SGP-T, i.e., the tripeptide FEG, localized at the carboxy terminal of the par ent heptapeptide. Both FEG and its d-isomeric form, feG, inhibited ana phylactic hypotension when administered intravenously prior to exposur e to the antigen. The peptide feG also inhibited anaphylactic hypotens ion when given orally 1 h before exposure to the antigen. SGP-T may be a prototype to a family of small peptides that modulate the immunolog ical and smooth muscle reactions to severe inflammatory (endotoxic and anaphylactic) reactions. (C) 1997 Wiley-Liss, Inc.