The Effects of Nitroglycerine
on the Redox Status of Rat Erythrocytes and Reticulocytes
S.D. MARKOVIĆ, B.I. OGNJANOVIĆ1, A. Š.
ŠTAJN, R. V. ŽIKIĆ, Z.S. SAIČIĆ1, R.M. RADOJIČIĆ2,
M.B. SPASIĆ1
Institute of Biology and Ecology, Faculty of Sciences,
University of Kragujevac, Kragujevac, 1Institute for
Biological Research “Siniša Stanković”, Department of
Physiology, Belgrade and 2Institute for Biochemistry
and Physiology, Faculty of Biology, University of Belgrade,
Belgrade, Serbia
Received April 26, 2005
Accepted August 15, 2005
On-line available October 17, 2005
Summary
The effects of nitroglycerine (NTG) are mediated by liberated
nitric oxide (NO) after NTG enzymatic bio-transformation in
cells. The aim of this study was to evaluate some products of
NTG bio-transformation and their consequences on the redox
status of rat erythrocytes and reticulocytes, considering the
absence and presence of functional mitochondria in these cells,
respectively. Rat erythrocyte and reticulocyte-rich red blood
cell (RBC) suspensions were aerobically incubated (2 h, 37 0C)
without (control) or in the presence of different concentrations
of NTG (0.1, 0.25, 0.5, 1.0 and 1.5 mM). In rat erythrocytes,
NTG did not elevate the concentrations of any reactive nitrogen
species (RNS). However, NTG robustly increased concentration of
methemoglobin (MetHb), suggesting that NTG bio-transformation
was primarily connected with hemoglobin (Hb). NTG-induced MetHb
formation was followed by the induction of lipid peroxidation.
In rat reticulocytes, NTG caused an increase in the levels of
nitrite, peroxinitrite, hydrogen peroxide, MetHb and lipid
peroxide levels, but it decreased the level of the superoxide
anion radical. Millimolar concentrations of NTG caused oxidative
damage of both erythrocytes and reticulocytes. These data
indicate that two pathways of NTG bio-transformation exist in
reticulocytes: one generating RNS and the other connected with
Hb (as in erythrocytes). In conclusion, NTG bio-transformation
is different in erythrocytes and reticulocytes due to the
presence of mitochondria in the latter.
Key words
Erythrocytes • Nitric oxide • Nitroglycerine • Oxidative stress
• Reticulocytes
|