Further research into the relationship between whole-body (and organ) protein turnover and the level of organ failure and energy expenditure is needed to characterize the status of protein metabolism in the early phase of critical illness before any recommendations can be given [ 31, 116, 134].
Additional studies are needed in critically ill patients to assess gastrointestinal uptake of AAs and to measure whole-body (and organ) protein turnover and AA oxidation for different levels of intake [ 31, 116, 134].
Previous studies have shown that telomere dysfunction impairs the maintenance of high turnover organs in aging mTerc -/- mice, specifically affecting the hematopoietic system and the intestinal epithelium [ 38- 40].
The continuous rounds of cellular proliferation and apoptosis during the menstrual cycle and any pregnancies create more possibilities for mutation during replication than most other tissues and organs, where cellular turnover is less frequent.
Although this has been the accepted consequence of macrophage infiltration in kidney disease, macrophages also play a critical role in normal organ development, cell turnover, and recovery from injury in many organs, including the kidney.
In conclusion, we have been able to show that in the pituitary, an organ where cell turnover is low and differentiated endocrine cells can proliferate, adult progenitors can be mobilized and made to differentiate toward a specific cell fate.
Slow-turnover organs of non-clonal plants, and litter from them, may leave small spots of organic matter accumulation in irregular, perhaps even random patterns as determined by seed dispersal and seed rain pattern.
On the other hand, fast-turnover organs of non-clonal plants such as short-lived leaves will be highly decomposable and leave no legacy of importance for soil development and biodiversity, as perhaps in the case of the annual Cakile maritime in European primary coastal sand dunes.
The adult lung epithelium is replaced over time, albeit very infrequently in comparison to organs exhibiting constant cellular turnover such as the skin and intestine.
Lactate, indispensable substrate of mammalian intermediary metabolism, allows shuttling of carbons and reducing power between cells and organs at a high turnover rate.
