AMP as a Better Delivery System of Adenosine

Adenosine and AMP are substances normally present in the body. Adenosine is also given for
the treatment of some heart rhythm problems and may be used to reduce heart damage during
heart attacks. The problem in using adenosine is that it is taken up by cells and, therefore,
very little of the adenosine we give by vein or in the artery actually reaches the tissue. We
propose to use AMP as a way to improve delivery of adenosine. AMP is inactive by itself, but
is converted to adenosine in tissue. We hope that by giving AMP we will increase levels of
adenosine in tissue. To see if this is true, we will give either adenosine or AMP into the
forearm artery while we measure how much adenosine reaches the forearm tissue.