Antihypertensive effect of oral nitrite uptake in the spontaneously hypertensive rat.
The lower blood pressure of vegetarians might partly be due to the high dietary load with nitrate which--to a certain extent--is further reduced to nitrite and finally to nitric oxide. To test this hypothesis, spontaneously hypertensive rats received drinking water containing 0, 25, 50 or 100 mmol/l NO2 during 56 days. Food was offered ad libitum or was restricted by 20% (pair-feeding) to simulate the lower energy consumption of vegetarians. Blood pressure, which was monitored at regular intervals, was lowered in a dose-dependent manner by nitrite. This effect was reversible and could not be enhanced by energy restriction. In volunteers plasma nitrate levels increased by a factor of 8 to 32 following the ingestion of a nitrate-rich meal, and mean methemoglobin concentrations increased from 1.2% to 2.4% indicating the endogenous formation of nitrite under these conditions.
Beier
S
S
Department of Pharmacology and Toxicology of Nutrition, University of Hohenheim, Stuttgart, Germany.
Classen
H G
HG
Loeffler
K
K
Schumacher
E
E
Thöni
H
H
D000328:Adult; D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects*; D001835:Body Weight / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid; D014676:Diet, Vegetarian; D004734:Energy Metabolism / Q000187:drug effects; D005260:Female; D006801:Humans; D008297:Male; D008706:Methemoglobin / Q000378:metabolism; D009566:Nitrates / Q000097:blood; D009569:Nitric Oxide / Q000378:metabolism / Q000494:pharmacology; D009573:Nitrites / Q000378:metabolism / Q000494:pharmacology*; D051381:Rats; D011918:Rats, Inbred SHR; D017207:Rats, Sprague-Dawley; D013056:Spectrophotometry, Ultraviolet
D000959:Antihypertensive Agents; D009566:Nitrates; D009573:Nitrites; D009569:Nitric Oxide; D008706:Methemoglobin