8 research outputs found
Influence of Radiation Dose in Computed Tomography on Antioxidant Enzyme Activity in Rabbit Erythrocytes
The objective of this study was to assess the radiation dose in computed tomography examinations of rabbits using different examination protocols and to correlate these values with the activity of antioxidant enzymes in their red blood cells following irradiation. The presented results revealed that a single, routine computed tomography scan exposure led to a different response of the activity of antioxidant enzymes in red blood cells regarding both dose and time. The results indicate that there is a dose threshold that is about 25 mGy. Doses below that level do not produce any significant changes in the level of antioxidant enzymes activity. On the other hand, the level just above that threshold had a significant impact on the antioxidant defence, but in a relatively short time period (2 hours after exposure), compared to the higher dose that requires a longer adaptive period
Effects of soy phytoestrogens on pituitary-ovarian function in middle-aged female rats
The aim of this study was to assess the effects of genistein (G) and
daidzein (D) on the histological, hormonal, and functional parameters of
the pituitary-ovarian axis in middle-aged female rats, and to compare
these effects with the effects of estradiol (E), commonly used in the
prevention and treatment of menopausal symptoms. Middle-aged (12 month
old) Wistar female rats subcutaneously received 35 mg/kg of G, or 35
mg/kg of D, or 0.625 mg/kg of E every day for 4 weeks. Each of the
treated groups had a corresponding control group. An intact control
group was also established. G and D did not change the intracellular
protein content within gonadotropic and lactotropic cells, but
vacuolization was observed in all the cell types. In contrast, E caused
an inhibition of gonadotropic and stimulation of lactotropic cells.
Also, ovaries of middle-aged female rats exposed to G or D have more
healthy primordial and primary follicles and less atretic follicles. E
treatment in the ovaries had a mostly negative effect, which is
reflected by the increased number of atretic follicles in all tested
classes. G and D provoked decrease in CuZnSOD and CAT activity, while E
treatment increased MnSOD and decreased CuZnSOD and GSHPx activity. All
the treatments increased serum estradiol and decreased testosterone
levels, while D and E increased the serum progesterone level. In
conclusion, soy phytoestrogens exhibited beneficial effects on
pituitary-ovarian function in middle-aged female rats, as compared to
estradiol.Ministry of Education, Science and Technological Development of the
Republic of Serbia {[}173009
Influence of radiation dose in computed tomography on antioxidant enzyme activity in rabbit erythrocytes
The objective of this study was to assess the radiation dose in computed
tomography examinations of rabbits using different examination protocols and
to correlate these values with the activity of antioxidant enzymes in their
red blood cells following irradiation. The presented results revealed that a
single, routine computed tomography scan exposure led to a different response
of the activity of antioxidant enzymes in red blood cells regarding both dose
and time. The results indicate that there is a dose threshold that is about
25 mGy. Doses below that level do not produce any significant changes in the
level of antioxidant enzymes activity. On the other hand, the level just
above that threshold had a significant impact on the antioxidant defence, but
in a relatively short time period (2 hours after exposure), compared to the
higher dose that requires a longer adaptive period. [Project of the Serbian
Ministry of Education, Science and Technological Development, Grant no.
173014: Molecular mechanisms of redox signalling in homeostasis: adaptation
and pathology