Diabetes mellitus is associated with a reductionof lipoprotein lipase (LPL) activity in adiposetissue and development of hypertriglyceridemia.To determine how a condition ofsevere insulin deficiency affects mammarygland LPL activity and mRNA expression duringlate pregnancy, streptozotocin (STZ) treated(40 mg/kg) and non-treated (control) virginand 20 day pregnant rats were studied. The gene discussed is LPL; the disease is diabetes mellitus.