Magnesium nitrate attenuates blood pressure rise in SHR rats.
The administration of magnesium supplements and nitrates/nitrites decreases arterial blood pressure and attenuates the development of hypertension-induced complications. This study was performed to examine the effects of treatment with magnesium nitrate on the development of hypertension and its complications in spontaneously hypertensive (SHR) rats. Male SHR rats with persistent hypertension at the age of 12-13 weeks were allocated to two groups according to their arterial blood pressure. Rats from the control group received purified water, while the experimental animals from the second group received magnesium nitrate dissolved in purified water at a dose of 50 mg/kg. After four weeks of treatment, blood pressure was measured, the anatomical and functional parameters of the heart were recorded using an ultrasonograph, vascular reactivity was assayed in organ bath experiments and the cardioprotective effects of magnesium nitrate administration was assayed in an ex vivo experimental heart infarction model. Treatment with magnesium nitrate significantly increased the nitrate concentration in the plasma (from 62 ± 8 μmol/l to 111 ± 8 μmol/L), and attenuated the increase in the arterial blood pressure. In the control and magnesium nitrate groups, the blood pressure rose by 21 ± 3 mmHg and 6 ± 4 mmHg, respectively. The administration of magnesium nitrate had no effect on the altered vasoreactivity, heart function or the size of the heart infarction. In conclusion, our results demonstrate that magnesium nitrate effectively attenuates the rise in arterial blood pressure. However, a longer period of administration or earlier onset of treatment might be needed to delay the development of complications due to hypertension.
Latvian Institute of Organic Synthesis, Aizkraukles Str. 21, Riga, LV-1006, Latvia, Rigas Stradins University, Dzirciema Str. 16, Riga, LV-1007, Latvia.
Reinis
R
Vilskersts
Latvian Institute of Organic Synthesis, Aizkraukles Str. 21, Riga, LV-1006, Latvia.
Janis
J
Kuka
Latvian Institute of Organic Synthesis, Aizkraukles Str. 21, Riga, LV-1006, Latvia.
Edgars
E
Liepinsh
Latvian Institute of Organic Synthesis, Aizkraukles Str. 21, Riga, LV-1006, Latvia.
Helena
H
Cirule
Latvian Institute of Organic Synthesis, Aizkraukles Str. 21, Riga, LV-1006, Latvia.
Anita
A
Gulbe
Latvian Institute of Organic Synthesis, Aizkraukles Str. 21, Riga, LV-1006, Latvia.
Ivars
I
Kalvinsh
Latvian Institute of Organic Synthesis, Aizkraukles Str. 21, Riga, LV-1006, Latvia, Rigas Stradins University, Dzirciema Str. 16, Riga, LV-1007, Latvia.
Maija
M
Dambrova
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D017616:Magnesium Compounds / Q000097:blood / Q000494:pharmacology*; D008297:Male; D009566:Nitrates / Q000097:blood / Q000494:pharmacology*; D051381:Rats; D011918:Rats, Inbred SHR
D017616:Magnesium Compounds; D009566:Nitrates; C018330:magnesium nitrate
heart infarction; hypertension; magnesium nitrate; spontaneously hypertensive rat; vascular reactivity