Does dopamine protection in restraint stress include both gastric and pancreatic lesions?

A simultaneous comparison between the effects of dopamine (D) drugs on gastric and pancreatic lesions (as yet known only from separate data) was carried out in Wistar rats (200 g) subjected to 6 h or 48 h restraint stress (RS). Investigated agents (mg/kg b.w.) (D-agonists (AG) bromocriptine 10, amantadine 20, D-antagonists (AN) haloperidol 5, domperidone 5) were given i.p. 1 h before RS. Unstressed (healthy control) and saline preatreated RS-rats were used for comparison. Previously described methods (Sikiric et al., EJP 147, 321, 1988 ; Sikiric et al., EJP 158, 61, 1988) were used for gastric/pancreatic lesions assesment. Results. Time-dependent worseing of stomach and pancreas lesions were noted in RS. 6 h. Stomach. We demonstrated a strong protection for DAG, and for DAN an aggravation inhibited by coadministration of DAG. Pancreas. Domperidone did aggravate the present lesions. No aditional influence of any investigated agent was observed. 48 h. Stomach. Pancreas. No influence of D-drugs was noted. Conclusion. Therefore, based on this parallel and simoultaneous comparison as well known actions of investigated agents as DAG or DAN, these data do not provide the clear evidence for general involvement of D-mechanism in both gastric and pancreatic lesions development in RS. However, the harmful effect of domperidone (6 h-RS), as rather specific peripheral DAN, consistently with our results on bille duct-ligated rats Sikiric et al., EJP 147, 321, 1988), suggests the need for further investigation in RS.