In one paper, with the running page heading of "the cocaine paradox," we presented evidence that in aortic strips of rabbit and isolated electrically-driven atria from guinea pig and cat, cocaine potentiated responses to norepinephrine and inhibited those to tyramine by blocking one and the same site on adrenergic nerve terminals.
He knew that nitroglycerine activated an enzyme in aortic muscle cells, guanylylcyclase, which increased cyclic GMP and caused relaxation.
Nearly 10% of people older than 65 suffer from an ailment called aortic stenosis, narrowing of the valve that releases a big surge of blood into the heart's major artery, the aorta.
When the valve doesn't open and close properly, a progressive condition known as aortic stenosis, a person may experience chest pain, shortness of breath and difficulty exercising.
RISK FACTOR: Aortic dissections are often proceeded by an enlargement of the first part of the aorta where it comes out of the heart, called an aortic aneurysm.