Serotonin plays a major role in serum-induced phospholipase C-mediated hydrolysis of phosphoinositides and DNA synthesis in vascular smooth muscle cells.
Whole blood serum (WBS) rapidly induced the phospholipase C-mediated hydrolysis of phosphoinositides and subsequently stimulated DNA synthesis in cultured rabbit vascular smooth muscle cells (VSMCs). Ketanserin, a serotonin (S2) receptor antagonist, markedly inhibited the WBS-induced phospholipase C reaction and DNA synthesis. Serotonin by itself had a weak mitogenic activity for VSMCs, but this vasoconstrictor markedly stimulated the platelet-derived growth factor- and epidermal growth factor-induced DNA synthesis. The stimulatory effect of serotonin on the growth factor-induced DNA synthesis was inhibited by ketanserin. The amount of serotonin contained in WBS was sufficient to induce the phospholipase C reaction and stimulate the growth factor-induced DNA synthesis. These results indicate that serotonin plays a major role in the WBS-induced phospholipase C-mediated hydrolysis of phosphoinositides and DNA synthesis in rabbit VSMCs and suggest that serotonin may act as an important growth regulator for VSMCs in addition to acting as a vasoconstrictor.
Araki
S
S
Department of Internal Medicine, 1st Division, Kobe University School of Medicine, Japan.
Kawahara
Y
Y
Fukuzaki
H
H
Takai
Y
Y
D000818:Animals; D001790:Blood Physiological Phenomena; D002478:Cells, Cultured; D004247:DNA / Q000096:biosynthesis*; D006868:Hydrolysis; D007650:Ketanserin / Q000494:pharmacology; D008297:Male; D008934:Mitogens / Q000494:pharmacology; D009131:Muscle, Smooth, Vascular / Q000378:metabolism*; D010716:Phosphatidylinositols / Q000378:metabolism*; D011817:Rabbits; D012701:Serotonin / Q000502:physiology*; D010738:Type C Phospholipases / Q000502:physiology*
D008934:Mitogens; D010716:Phosphatidylinositols; D012701:Serotonin; D004247:DNA; D007650:Ketanserin; D010738:Type C Phospholipases