Intracellular free calcium concentration and thromboxane A2 formation of vascular smooth muscle cells are influenced by fish oil and n-3 eicosapentaenoic acid.
The effect of fish oil and n-3 eicosapentaenoic acid (EPA) on intracellular free calcium concentration ([Ca2+]i) and thromboxane B2 (TXB2) formation in resting and stimulated cultured rat vascular smooth muscle cells (VSMC) was examined. In resting control cells [Ca2+]i was 147 +/- 15 nmol l-1 (mean +/- SEM, n = 4). After pretreatment of the cells with fish oil or EPA for 24 days the resting [Ca2+]i was decreased to 126 +/- 10 nmol l-1 and 84 +/- 8 nmol-1, respectively. After stimulation of untreated control cells with either 100 nmol l-1 angiotensin II (AII), 40 micrograms ml-1 low-density lipoprotein (LDL), or 100 ng ml-1 of recombinant platelet-derived growth factor (PDGFAB), [Ca2+]i was (in nmol l-1) 306 +/- 31, 217 +/- 25 and 213 +/- 16. Treatment of cells with fish oil or EPA reduced the stimulatory effect of the agonists, and the following [Ca2+]i values (in nmol l-1) were found: 199 +/- 21, 131 +/- 10, 148 +/- 13; and 175 +/- 11, 98 +/- 12, and 103 +/- 6, respectively. PDGFAB induced a four fold increase in TXB2-generation (270 +/- 28 pg mg-1 cell protein compared with 61 +/- 8.2 pg mg-1 in unstimulated control cells) within 6 min. In cells pretreated with fish oil or EPA, TXB2-formation was reduced by 54% and 44%, respectively.


CONCLUSIONS
in rat VSMC stimulated by a variety of vasoactive agonist, fish oil and EPA can markedly attenuate intracellular mechanisms related to changes of cytosolic calcium concentration and eicosanoid production.(ABSTRACT TRUNCATED AT 250 WORDS)
Locher
R
R
Department of Internal Medicine, University Hospital, Zürich, Switzerland.
Sachinidis
A
A
Brunner
C
C
Vetter
W
W
D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D015118:Eicosapentaenoic Acid / Q000494:pharmacology*; D005395:Fish Oils / Q000494:pharmacology*; D006801:Humans; D008077:Lipoproteins, LDL / Q000494:pharmacology; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology; D051381:Rats; D013928:Thromboxane A2 / Q000096:biosynthesis*
D005395:Fish Oils; D008077:Lipoproteins, LDL; D010982:Platelet-Derived Growth Factor; D000804:Angiotensin II; D013928:Thromboxane A2; D015118:Eicosapentaenoic Acid; D002118:Calcium