Abstract: Agents for improving blood circulation containing gelatin or solubilized collagen as the effective component. The agents facilitate and restore impaired peripheral blood flow, prevent the occurence of circulatory insufficiency, stabilize plasma cells, prevent coagulation of blood, and improve maintenance of various devices for assisting extracorporeal circulation.

Abstract: An agent for curing peripheral circulation insufficiency comprising .alpha..sub.1 -acid glycoprotein. A blood flow in peripheral blood vessels cause a trouble by hardening of the blood vessels, lowering of blood pressure or acceleration of a fibrinolysinemia function to bring about peripheral circulation insufficiency. But .alpha..sub.1 -acid glycoprotein has a function that it prevents coagulation and agglutination of the solid component in the blood and, particularly, it accelerates passability of the red blood corpuscles in the vital peripheral circulation system to alleviate or remove the peripheral circulation insufficiency. .alpha..sub.1 -acid glycoprotein has very low toxicity and is preferred to be administered into an artery or a vein in a form of preparation for injection, etc.