Changes in insulin immunoreactivity across the coronary circulation in man during infusions of glucose and a fat...

The extraction of immunoreactive insulin by the human heart has been examined using the technique of coronary sinus catheterisation. The subjects were 12 male volunteers. During the study infusions of a fat emulsion and glucose were given in an effort to create a "steady fed state". The higher arterial insulin immunoreactivities which were observed during the infusions were associated with greater arterial coronary sinus differences in insulin immunoreactivity. The possibility of insulin degradation by the heart is discussed. During prolonged exercise the process of insulin removal by the heart appeared more active.