["Classical" apo B,E-receptor does not mediate the activating effect of low density lipoproteins on the second messenger system in human platelets and vascular smooth muscle cells].
The possible role of the "classical" LDL receptor (apo B,E-receptor) in activation of second messenger systems in human platelets and vascular smooth muscle cells (VSMC) has been investigated. The LDL-induced elevation of free cytoplasmic Ca2+ in platelets and VSMC was not inhibited by EGTA, which is known to block the LDL interaction with the apo B,E-receptor. Heparin abolished the binding of LDL to the apo B,E-receptor but did not influence the LDL-induced accumulation of inositol phosphates in VSMC. Acetylation or carbamylation of lysine residues, or modification of arginine residues of apo B by cyclohexanedione treatment did not influence the ability of LDL to activate the phosphoinositide turnover in VSMC. It was found also that LDL are capable of activating cell-signalling systems in platelets of homozygous hypercholesterolemic patients and in VSMC from Watanabe rabbits lacking functional apo B,E-receptors. These data indicate that the "classical" high affinity LDL receptor does not mediate the activating effects of LDL on platelets and VSMC.
Bochkov
V N
VN
Kuz'menko
E S
ES
Rezink
T
T
Tkachuk
V A
VA
D000107:Acetylation; D001120:Arginine / Q000737:chemistry; D001792:Blood Platelets / Q000378:metabolism*; D002219:Carbamates / Q000378:metabolism; D002478:Cells, Cultured; D006493:Heparin / Q000494:pharmacology; D006801:Humans; D006937:Hypercholesterolemia / Q000097:blood; D007295:Inositol Phosphates / Q000378:metabolism; D008077:Lipoproteins, LDL / Q000378:metabolism*; D008239:Lysine / Q000737:chemistry; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000378:metabolism*; D010716:Phosphatidylinositols / Q000378:metabolism; D011973:Receptors, LDL / Q000187:drug effects / Q000378:metabolism*; D015290:Second Messenger Systems
D002219:Carbamates; D007295:Inositol Phosphates; D008077:Lipoproteins, LDL; D010716:Phosphatidylinositols; D011973:Receptors, LDL; D006493:Heparin; D001120:Arginine; D008239:Lysine
"Klassicheskiĭ" apo B,E-retseptor ne uchastvuet v aktiviruiushchem vliianii lipoproteidov nizkoĭ plotnosti na sistemy vtorichnykh posrednikov v trombotsitakh i gladkomyshechnykh kletkakh sosudov cheloveka.