The antidepressant effect of an antiulcer pentadecapeptide BPC 157 in Porsolt's test and chronic unpredictable stress in rats. A comparison with antidepressants

Various antidepressants have antiulcer activity. Likewise, the models curre ntly used in ulcers and depression disorders research have a considerable d egree of similarity. Therefore, the possibility that depression disorders c ould be effectively influenced by a primary antiulcer agent with a cyto/org anoprotective activity, such as the novel stomach pentadecapeptide BPC 157, was investigated in two rat depression assays. First, a forced swimming te st (a Porsolt's procedure) was used. As a more severe procedure, chronic un predictable stress (after 5 d of unpredictable stress protocol, once daily drug application during stress procedure, open field-immobility test assess ment at fourth or sixth day of medication) was used. In a forced swimming t est, a reduction of the immobility time in BPC 157 (10 mu g, 10 ng.kg(-1) i .p.) treated rats corresponds to the activity of the 15 mg or 40 mg (i.p.) of conventional antidepressants, imipramine or nialamide, respectively, giv en according to the original Porsolt's protocol. In chronic unpredictable s tress procedure, particular aggravation of experimental conditions markedly affected the conventional antidepressant activity, whereas BPC 157 effecti veness was continuously present. The effect of daily imipramine (30 mg) med ication could be seen only after a more prolonged period, but not after a s horter period (i.e., 4-d protocol). In these conditions, no delay in the ef fectiveness was noted in BPC 157 medication and a reduction of the immobili ty of chronically stressed rats was noted after both 4 and 6 d of BPC 157 ( 10 mu g, 10 ng) medication. (C) 2000 Elsevier Science Ltd. Published by Edi tions scientifiques et medicales Elsevier SAS.