Page 119 - The Cell in 40 Topics

n amino acid by the name of L-arginine; the NO synthesis
enzyme; nicotinamide adenine dinucleotide phosphate;
calmodulin; oxygen; flavin mononucleotide; flavin adenine
dinucleotide; tetrahydrobiopterine ...
Probably most people never have heard these words ever before. Yet
the endothelial cell knows all these microscopic compounds very well and
uses them for its production of the NO molecule (Figure 94).
Factories manufacturing chemical products using modern-day tech-
nology are trillions of times larger than endothelial cells. Nonetheless, the
advanced technology of the microscopic factory known as the endothelium
is far superior to that of any human technology.
The endothelial cell knows which chemical substance it has to use,
and in what proportion, in order to produce the nitric oxide molecule.
There is never any incidence of wrong or incorrect production. For exam-
ple, it does not produce laughing gas (N O) instead of NO. Remember,
2
were the endothelial cells to produce fewer messengers than necessary, our
veins would contract and our blood pressure would rise rapidly, leading to
a heart attack. In the event of excessive production, our veins would over-

117