Found in eukaryotic plasma membranes, sphingolipids have emerged as a class of lipid mediators believed to be important for endogenous modulation of cardiovascular function [33], [34].
Transitions at CpG sites are believed to be caused by endogenous processes.
Pancreatic polypeptide was originally isolated from the pancreas and is believed to be the primary endogenous ligand for the Y4R (Kimmel et al, 1975).
These rhythmic processes are believed to be driven by endogenous molecular clocks that regulate rhythmic expression of clock-controlled genes (CCGs).
The endocannabinoid system is believed to be actively involved in endogenous protective mechanisms in skin barrier function; application of PEA/AEA could augment local production of lipids and inhibit their degradation (via fatty acid amide hydrolase) in the stratum granulosum, and could therefore serve as another therapeutic method for combating dry skin and reducing itching.
Oxidative damage to DNA caused by reactive oxygen species is believed to be a major type of endogenous cellular damage, and more than 80 different oxidative modifications of DNA bases and sugar backbone have been identified to date [1].
Surprisingly, although SR is believed to be the primary source of endogenous d-serine, the loss of this enzyme did not entirely eliminate the presence of retinal d-serine.
Diurnal preference is believed to be related to the phase of endogenous circadian rhythms.
For a long time nitrite (NO2-) was believed to be an inert metabolite of the endogenous vasodilator NO.
Thus, the nature of an endogenous ligand believed to be expressed on T lymphocytes is an open question and will remain under review as new oligosaccharide probes become available.
Cystatin C, an endogenous protein believed to be produced by all nucleated cells, is less affected by age, race, and muscle mass and, in the general population, associates more strongly with all-cause and cardiovascular mortality than does serum creatinine (11, 12).
