High-frequency ultrasound for assessing the renal characteristics of spontaneous type 2 diabetes mellitus <i>db/db</i> mice

There are few ultrasonographic studies on the spontaneous type 2 diabetes mellitus db/db mouse. Our objective was to dynamically investigate and assess renal morphological and hemodynamic changes in spontaneous T2DM db/db mice through high-frequency ultrasound. Eighteen male db/db mice (the model group) and twelve male db/+ mice (the control group) were included. Body weight and fasting blood glucose were measured at the ages of 8, 16 and 32 weeks. High-frequency ultrasound examinations were conducted at the same ages. Compared with those in the control group, hematoxylin-eosin and Masson staining revealed pathological changes in the renal tissue of the db/db mice at 16 weeks of age, and the lesions were significantly aggravated at 32 weeks of age. The body mass of the mice in the model group increased significantly at 8, 16 and 32 weeks of age, and the kidney volume measured by ultrasound also increased with age. Compared with those of the control group, the blood flow scores determined via power Doppler were significantly different. The peak systolic velocity (PSV), end diastolic velocity (EDV), and resistive index (RI) of the renal artery and the PSV, EDV, and RI of the segmental artery were significantly different at the sixteenth week compared with those that at the eighth week. The results of high-frequency ultrasound revealed that the renal hemodynamics of db/db mice changed at the sixteenth weeks.