Control of blood glucose is a key objective in the management of type I and type II diabetes mellitus (DM) as well. The basis for development of new antidiabetic drug is the proper control of the hyperglycemia and fur­ther more could manage accompany­ing disorders especially dyslipidemia. The aim of this study was to investi­gate a newly developed (3₃ adrener-gic agonist (BRL 37344) to confirm its effect on blood glucose in two animal models of D.M. which induced by streptozotocin (STZ) in a dose of 70 or 40 mg/Kg for induction of type 1 or type II D.M., respectively and try to explore for the possible underlying mechanism of this effect. Oral admin-
istration of BRL 37344 for 4 succes­sive days in either STZ type I or STZ type II diabetic rats produced signifi­cant reduction in mean serum glu­cose level and non-significant change in mean serum insulin level in com­parison with non treated STZ diabetic rats. BRL treatment significantly in­creased glucokinase activity and de­creased glucose-6-phosphatase ac­tivity in hemogenated hepatic tissues which were isolated from both STZ diabetic rat models. In in-vitro study, BRL produced non-significant chang­es in insulin secretion from isolated pancreatic tissue of STZ type II dia­betic rats, while BRL showed signifi­cant increase in glucose uptake by isolated soleus muscle from both STZ