Effect of septicaemia on the plasma levels of biopterin and nitric oxide metabolites in rats and rabbits.
Live Escherichia coli decreased mean arterial blood pressure in rabbits from 67 to 20 mmHg. E. coli did not affect blood pressure in rats but did significantly increase heart rate by 29%. To related the cardiovascular effects with putative relevant biochemical pathways, the plasma levels of nitrate + nitrite (NOx) and biopterin, representing the main metabolites of nitric oxide and tetrahydrobiopterin, respectively, were determined in conscious rats and rabbits after treatment with live E. coli. In rats, E. coli induced a rapid 43% increase in the plasma level of biopterin preceding the 7- to 26-fold increase in NOx level. In rabbits, no increase in the NOx level was observed despite a 3- to 5-fold increase in the biopterin level at 6-10 hr posttreatment. It is concluded that the synthesis of tetrahydrobiopterin precedes nitric oxide synthesis after induction of septicaemia in the rat. After the induction of septicaemia, rabbits show a clear hypotensive response and an increase in biopterin level but no concomitant increase in NOx. Biopterin apparently represents a more appropriate biochemical marker of septic shock than does NOx.
van Amsterdam
J G
JG
Department of Pharmacology, National Institute of Public Health and Environmental Protection, Bilthoven, The Netherlands.
van den Berg
C
C
Zuidema
J
J
te Biesebeek
J D
JD
Rokos
H
H
D000818:Animals; D016470:Bacteremia / Q000097:blood* / Q000209:etiology / Q000503:physiopathology; D001708:Biopterins / Q000031:analogs & derivatives / Q000097:blood*; D001794:Blood Pressure; D004927:Escherichia coli Infections / Q000097:blood / Q000209:etiology / Q000503:physiopathology; D006339:Heart Rate; D009569:Nitric Oxide / Q000097:blood*; D011817:Rabbits; D051381:Rats; D013045:Species Specificity; D013997:Time Factors
D001708:Biopterins; D009569:Nitric Oxide; C003402:sapropterin