Renal vasodilation in response to coronary artery ligation in the dog.

1. The effects of coronary artery ligation on renal vascular resistance were determined with and without pretreatment with methylprednisolone succinate or atropine in anaesthetized dogs. 2. With coronary artery ligation alone renal blood flow is maintained constant in spite of a reduction in arterial blood pressure, indicating renal vasodilation. 3. Pretreatment with methylprednisolone succinate prevents the fall in arterial blood pressure. 4. After pretreatment with atropine, renal blood flow falls in response to the reduction in arterial blood pressure, suggesting inhibition of cholinergic renal vasodilatation.