Neuropeptide degradation by large vessel and microvessel-derived endothelial cells in vitro: cell surface catabolism of thyrotropin releasing hormone (TRH).
Cell surface ectopeptidase activity of purified, cultured large vessel and microvessel-derived endothelial cells (EC) was studied. Degradation of thyrotropin releasing hormone (TRH), and production of cyclo-His-Pro was significantly increased (P less than 0.001) in large vessel EC compared with microcapillary EC. Since the rate of catabolism in the microvascular capillary bed is 5 times less than that in the large vessel wall, peptide concentrations are likely maintained longer in close proximity to their site of biosynthesis, where they are presumably most active.
Rozental
J M
JM
Neurology Service, Wm. S. Middleton Veterans Administration Hospital, Madison, WI 53705.
Kaminska
G
G
Turner
J
J
Schwartz
T
T
Cadahia
V
V
Brooks
B R
BR
D000626:Aminopeptidases / Q000378:metabolism*; D000818:Animals; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D009479:Neuropeptides / Q000378:metabolism*; D013973:Thyrotropin-Releasing Hormone / Q000378:metabolism*
D009479:Neuropeptides; D013973:Thyrotropin-Releasing Hormone; D000626:Aminopeptidases