We showed that rapid-eye-movement
(REM) sleep deprivation (RSD) by the platform-over-water method inhibits hippocampal cell proliferation in adrenalectomized rats with low-dose corticosterone clamp. This procedure also greatly disrupts daily behavioral rhythms. Given recent evidence for circadian clock regulation of cell proliferation, we asked whether disruption of circadian rhythms might play a role in the anti-neurogenic effects of sleep loss. Male Sprague Dawley rats were subjected to a 4-day RSD procedure or were exposed to constant bright light (LL) for 4 days or 10 weeks, a non-invasive procedure for eliminating circadian rhythms of behavior and physiology in this species. Proliferating cells in the granule cell LDN-193189 cost layer of the dentate gyrus were identified by immunolabeling for the thymidine analogue 5-bromo-2-deoxyuridine. Consistent with our previous results, the RSD procedure suppressed cell proliferation by similar to 50%. By contrast, although LL attenuated or eliminated daily rhythms of activity and sleep-wake without affecting daily amounts of REM sleep, cell proliferation was not affected. Melatonin, a nocturnally secreted neurohormone that is inhibited by light, has been shown to promote survival of new neurons. We found that 3-weeks of LL eliminated daily rhythms and decreased plasma
melatonin by 88% but did not significantly affect either total selleck compound cell survival or survival of new neurons (doublecortin+). Finally, we measured cell proliferation selleckchem rates at the beginning and near the end of the daily light period in rats entrained to a 12:12 light/lark (LD) cycle, but did not detect a daily rhythm. These results indicate that the anti-neurogenic effect of RSD is not secondary to disruption of circadian rhythms, and provide no evidence that hippocampal cell proliferation and survival are regulated by the circadian system or by nocturnal secretion of pineal melatonin. (C) 2011 IBRO. Published
by Elsevier Ltd. All rights reserved.”
“Objective: Blood vessels are an important tissue for allogenic vessel replacement surgery, which is needed for example following infection of artificial grafts. For tissue banking, European legislation requires evidence of tissue sterility with assays performed over 1 week. Currently, used cold storage solutions do not protect vascular function longer than 2 days. This does not allow completion of microbiological testing. This discrepancy has almost completely stopped vessel banking in Europe.
Methods: We compared the recently developed storage solution TiProtec (Dr F Kohler Chemie, Bensheim, Germany) with traditionally used histidine-tryptophan-ketoglutarate (HTK) solution, 0.9% NaCl, and phosphate-buffered saline (physiological saline solution [PSS]) solution for extended cold (4 degrees C) storage up to 25 days.