Fig. 4

GQD and metformin significantly increased glucagon positive cell number of STZ induced diabetic rats. A, Immunohistochemical staining of glucagon in the pancreas; B, Glucagon positive cell number of islets. The glucagon cell number of the GQD or metformin group was increased compared to the diabetes group (p < 0.05); C, Total cell number of islets. The diabetes group had a lower total islet cell number compared to the control (p < 0.001) and GQD or metformin treatment increased the total islet cell number of diabetic rats (p < 0.05); D, Glucagon positive cell ratio of islets. The glucagon cell ratio was higher in the diabetes group than in the control group (p < 0.001), GQD treatment increased the total glucagon cell ratio of diabetic rats; E, Average islet area of different groups. Diabetes decreased islet area compared to the control group (p < 0.05). (* p < 0.05, ** p < 0.01, *** p < 0.001; Scale bar: 50 μm; magnification: 400×; n = 22–30)