Bromocriptine improves glucose tolerance in obese mice via central dopamine D2 receptor-independent mechanism
Fig 4
Daily administration of bromocriptine improved glucose metabolism in orexin knockout mice under diet-induced obese conditions.
(A-J) Wild-type (Orexin+/+) and orexin knockout (Orexin-/-) mice at 10 weeks of age were fed a high-fat diet for 8 weeks, and bromocriptine (BC, 10 mg/kg, i.p.) or vehicle (10% ethanol) was then administered daily at ZT14 for 2 weeks. n = 4–7 per group. (A-B) Transient increases in blood glucose levels after the BC injection at ZT14 on day 1 and day 2 in Orexin+/+ (A) and Orexin-/- mice (B). (C-D) Random fed blood glucose levels measured at ZT8 after 1 and 2 weeks of the BC treatment in Orexin+/+ (C) and Orexin-/- mice (D). (E-F) The glucose tolerance test conducted 2 weeks after the daily administration of BC in Orexin+/+ (E) and Orexin-/- mice (F). (G-H) The insulin tolerance test conducted 2 weeks after the daily administration of BC in Orexin+/+ (G) and Orexin-/- mice (H). (I-J) Serum insulin levels during the glucose-stimulated insulin secretion test conducted 2 weeks after the daily administration of BC in Orexin+/+ (I) and Orexin-/- mice (J). Values are expressed as the means ± S.D. * p < 0.05 and **p < 0.01 by the Student’s t-test.