| |
The STUDIA UNIVERSITATIS BABEŞ-BOLYAI issue article summary
The summary of the selected article appears at the bottom of the page. In order to get back to the contents of the issue this article belongs to you have to access the link from the title. In order to see all the articles of the archive which have as author/co-author one of the authors mentioned below, you have to access the link from the author's name. |
|
| |
Abstract: Female white Wistar rats were treated as specified below for an average period of 10 weeks. The control group (C) received a standard diet. The ethanol-fed group (E) consumed the same diet but their drinking water contained 10% (v/v) ethanol. The third group (ES) received the same treatment as E, but, in addition, the rats were supplemented with 8% Spirulina powder in their food. A fourth group received the standard diet plus the Spirulina supplement (S). At the end of the period, the rats were sacrificed and part of their liver was used for the preparation of mitochondria. Membrane potential (ΔΨ), calcium fluxes and matrix swelling were followed spectrophotometrically, in some cases by parallel recordings, using a diode array instrument, while ΔΨ was also recorded fluorimetrically. The respiration and all the associated phenomena monitored by us were triggered by the addition of succinate in the presence of rotenone. From the comparison of the spectrophotometric recordings, we observed a good correlation between the concentration of calcium added to the mitochondrial suspension, the moments of ΔΨ collapse, swelling and calcium release (massive efflux). The sensitivity of mitochondria to calcium was quantified in terms of 10-μM pulses added until ΔΨ collapse and/or calcium efflux and served as a reliable index of comparison between groups. The permeability transition (PT) induced by swelling was confirmed by the inhibitory effect of cyclosporin A. Important differences were noticed between the mitochondria of the four groups regarding the kinetics of the absorbancy changes associated with the generation/collapse of ΔΨ, Ca2+ movements and swelling. In general, mitochondria from ethanol-treated rats (E) were more sensitive to calcium, while those of the S group were the least sensitive. The double- treated group (ES) had practically the same performance as the C group. We conclude that Spirulina utilised as a food additive significantly enhances the resistance of mitochondria to calcium-induced membrane potential collapse and permeability transition.
Keywords: ethanol-fed rats, Spirulina, mitochondrial membrane potential, calcium efflux, permeability transition. |
|
