X-Message-Number: 17314 From: Date: Sat, 18 Aug 2001 17:01:33 EDT Subject: Re: CryoNet #17291 O2 is bad Dans un courrier dat du 17/08/01 11:01:10 Paris, Madrid (Heure d' t ), a crit : << From: Subject: Bozzoneti: O2 is bad! OK, it's a necessary evil. But when we want to generate more superoxide radicals (there might be some more H2O2 too) in a cell culture dish and cause accelerated telomere shortening, we use 40% O2 in the incubator. Unless you live in the Himalayas, you should try to use chemical means (CoQ10 or whatever) to make better use of less oxygen. -Bill >> More O2 = telomere shortening = O2 is bad? Let me find another interpretation: In a petri dish, there is cell food and no regulating growth factor. More O2 imply the possibility to process more food and so have more energy. That energy is used first for reproduction purpose so here are more cell generations. The result is shortened telomeres. Now think of the cell in an organ: More O2 give more possibilities to produce energy and so the cell will get leaner because food supply will not expand in the same way. There are growth regulators, so the energy can't go simply in reproductive tasks. It may be wasted or if the cell has a good repair system, it may be invested in it without diverting any supply from other activities. More energy imply too more protein synthesis and particularly more peroxyde scavengers such SOD (Super Oxyde Dismutase) The cell would then end up with less H2O2 the true vilain. I think there may be a benefit to use a 30 per cent oxygen atmosphere, I'll test it. Yvan Bozzonetti. Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=17314