An. Bateson et al., RAPID INCREASE IN INDUCIBLE NITRIC-OXIDE SYNTHASE GENE-EXPRESSION IN THE HEART DURING ENDOTOXEMIA, European journal of pharmacology, 303(1-2), 1996, pp. 141-144
Inducible, Ca2+-independent nitric oxide (NO) synthase activity in the
heart is elevated during endotoxemia and the resulting excess release
of NO depresses cardiac contractile function. We show here that this
is due to an extremely rapid induction of inducible NO synthase gene e
xpression. Following injection of endotoxin (bacterial lipopolysacchar
ide) in rats we detected increased inducible NO synthase mRNA levels i
n the left ventricular wall within 30 min which then peaked at 3 h. Th
is was followed by an increase in myocardial inducible NO synthase enz
yme activity and plasma levels of NO metabolites, nitrate and nitrite,
which peaked at 6 and 12 h, respectively. The extremely rapid inducti
on of inducible NO synthase may serve to protect the heart against mic
robial infection and concomitantly alter myocardial mechanical functio
n.