scholarly journals PHYSIOLOGICAL AND BIOCHEMICAL CHANGES IN ALGAL CULTURES OF CHLORELLA VULGARIS AND SYNECHOCYSTIS SALINA (MESOPHILIC AND ANTARCTIC ISOLATES) OCCURING AFTER TREATMENT WITH UV-B RADIATION

2017 ◽  
pp. 73-82
Author(s):  
Dilyana Doneva ◽  
Juliana Ivanova ◽  
Lyudmila Kabaivanova

Determination of biomass production and viability of algal cells of Chlorella vulgaris and Synechocystis salina exposed to UV-B radiation were carried out in this study together with comparison of the mesophilic and antarctic isolates of both investigated strains. Estimation of the content of the pigments: chlorophyll a, chlorophyll b, β-carotene, C-phycocyanin and allo-phycocyanin in algal cells exposed to UV-B radiation was also accomplished. The obtained results showed that the antarctic algae are more resistant to oxidative stress than their mesophilic counterparts. The antarctic isolates of Ch. vulgaris and S. salina compared with the mesophilic ones - up to 72 h showed tolerance to low exposures of radiation, expressed in a slight stimulation of growth and viability of the cells. Antarctic isolates also showed greater resistance to low doses of UV-B radiation manifested by stimulation of the synthesis of chlorophyll a and β-carotene. The registered increase in the amount of C- and allo-phycocyanin in antarctic isolates of S. salina showed that they had developed protective strategies against UV-B radiation by increasing the concentration of the phycobiliproteins. As a result of increased UV-B background, in antarctic isolates, stronger antioxidant defence mechanisms are triggered, which proved the possibility of using them as markers of oxidative stress.

1974 ◽  
Vol 47 (12) ◽  
pp. 3001-3005 ◽  
Author(s):  
Yoshihiro Nakato ◽  
Takeshi Chiyoda ◽  
Hiroshi Tsubomura

2007 ◽  
Vol 32 (4) ◽  
pp. 677-685 ◽  
Author(s):  
Cecilia M. Shing ◽  
Jonathan M. Peake ◽  
Shannon M. Ahern ◽  
Natalie A. Strobel ◽  
Gary Wilson ◽  
...  

We examined the influence of 3 consecutive days of high-intensity cycling on blood and urinary markers of oxidative stress. Eight highly-trained male cyclists (VO2 max76 ± 4 mL·kg–1·min–1; mean ± SD) completed an interval session (9 exercise bouts lasting 30 s each, at 150% peak power output) on day 1, followed by 2 laboratory-simulated 30 km time trials on days 2 and 3. The cyclists also completed a submaximal exercise trial matched to the interval session for oxygen consumption. Blood was collected pre- and post-exercise for the determination of malondialdehyde (MDA), total antioxidant status (TAS), vitamin E, and the antioxidant enzyme activity of superoxide dismutase and glutathione peroxidase, while urine was collected for the determination of allantoin. There were significant increases in plasma MDA concentrations (p < 0.01), plasma TAS (p < 0.01), and urinary allantoin excretion (p < 0.01) following the high-intensity interval session on day 1, whereas plasma vitamin E concentration significantly decreased (p = 0.028). Post-exercise changes in plasma MDA (p = 0.036), TAS concentrations (p = 0.039), and urinary allantoin excretion (p = 0.031) were all significantly attenuated over the 3 consecutive days of exercise, whereas resting plasma TAS concentration was elevated. There were no significant changes in plasma MDA, TAS, or allantoin excretion following submaximal exercise and there were no significant changes in antioxidant enzyme activity over consecutive days of exercise or following submaximal exercise. Consecutive days of high-intensity exercise enhanced resting plasma TAS concentration and reduced the post-exercise increase in plasma MDA concentrations.


2001 ◽  
Vol 20 (3) ◽  
pp. 232-238 ◽  
Author(s):  
Isabelle A. Hininger ◽  
Anita Meyer-Wenger ◽  
Ulrich Moser ◽  
Anthony Wright ◽  
Susan Southon ◽  
...  

2005 ◽  
Vol 827 (1) ◽  
pp. 109-118 ◽  
Author(s):  
Marica Orioli ◽  
Giancarlo Aldini ◽  
Giangiacomo Beretta ◽  
Roberto Maffei Facino ◽  
Marina Carini

2014 ◽  
Vol 84 (Supplement 1) ◽  
pp. 25-29 ◽  
Author(s):  
Guangwen Tang

Humans need vitamin A and obtain essential vitamin A by conversion of plant foods rich in provitamin A and/or absorption of preformed vitamin A from foods of animal origin. The determination of the vitamin A value of plant foods rich in provitamin A is important but has challenges. The aim of this paper is to review the progress over last 80 years following the discovery on the conversion of β-carotene to vitamin A and the various techniques including stable isotope technologies that have been developed to determine vitamin A values of plant provitamin A (mainly β-carotene). These include applications from using radioactive β-carotene and vitamin A, depletion-repletion with vitamin A and β-carotene, and measuring postprandial chylomicron fractions after feeding a β-carotene rich diet, to using stable isotopes as tracers to follow the absorption and conversion of plant food provitamin A carotenoids (mainly β-carotene) in humans. These approaches have greatly promoted our understanding of the absorption and conversion of β-carotene to vitamin A. Stable isotope labeled plant foods are useful for determining the overall bioavailability of provitamin A carotenoids from specific foods. Locally obtained plant foods can provide vitamin A and prevent deficiency of vitamin A, a remaining worldwide concern.


1962 ◽  
Vol 39 (1) ◽  
pp. 13-21 ◽  
Author(s):  
Roger A. Gorski ◽  
Charles A. Barraclough

ABSTRACT We have previously suggested that the failure of the androgen-sterilized, persistent-oestrous rat to ovulate, following electrical stimulation of the median eminence structures of the hypothalamus, is due to an insufficiency in adenohypophyseal LH concentration. Using the ovarian ascorbic acid technique for quantitative determination of pituitary LH content, the present studies have demonstrated that the sterile rat pituitary gland contains one-third the LH content of the normal prooestrous gland. Furthermore, not only does progesterone priming of this persistent-oestrous rat result in a 75 % increase in LH concentration, but on hypothalamic stimulation sufficient LH is released to induce ovulation. The decrease in LH concentration which accompanies ovulation in the progesterone-primed, sterile rat is approximately 45 % of the total gland content as compared with a 51 % decrease in pituitary content in the normal cyclic rat.


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