Clonidine prevents insulin resistance and hypertension in obese dogs

The role that the central sympathetic nervous system plays in the developme nt of obesity hypertension and insulin was evaluated by feeding dogs a high fat diet with or without clonidine treatment. Thirteen adult mongrel dogs were chronically instrumented and randomly assigned to receive either a hig h fat diet and no clonidine (n=6) or a high fat diet plus clonidine (n=7), 0.3 mg BID. Blood pressure, heart rate, plasma insulin, and electrolytes we re measured daily. Insulin resistance was assessed with a multiple-dose eug lycemic clamp (1, 2, and 30 mU.kg(-1).min(-1)) before and after 1, 3, and 6 weeks of the high fat diet. Clonidine prevented the hypertension, tachycar dia, and insulin resistance associated with feeding dogs the high fat diet but did not affect weight gain. The present study suggests that the central sympathetic nervous system plays a critical role in the development of bot h insulin resistance and hypertension associated with feeding dogs a high f at diet.