DPP4 and hydrops fetalis: In situ histochemical demonstration of alkaline phosphatase (AP) activity, which points out the function of the arterial part of capillaries as well as the activity of dipeptidyl peptidase IV (DPPIV), reflecting function of venous part of capillary network, is demonstrated in Fig. 1B. Activity of AP (blue colour) was reduced in response to ACF-induced HF only in TGR heart but increased due to treatment with losartan and trandolapril in both rat strains (Fig. 1C).