title: Differential regulation of the formation of prostaglandins and related substances from arachidonic acid and from dihomogammalinolenic acid. II. Effects of vitamin C.
abstract: Vitamin C over the concentration range 10 to 100 microgram/ml (5.7-57 x 10-5 M) caused a dose dependent and highly significant enhancement of conversion of 14C-dihomogammalinolenic acid (DGLA) to prostaglandin (PG) E1 and to thromboxane (Tx) B1 by human platelets. Vitamin C had no effect on conversion of 14C-arachidonic acid to PGE2 and TxB2. The concentration range is relevant to physiology: in some cells which concentrate the vitamin, such as polymorphonbuclear leucocytes and the adrenal cortex, vitamin C concentrations may be substantially higher than 100 microgram/ml. Vitamin C can therefore selectively enhance the formation of cyclo-oxygenase generated products from DGLA without changing formation of those from AA. This effect can account for a number of the known actions of vitamin C including its effect on the immune system. The implications of this finding are discussed.
mesh_terms: D015126:8,11,14-Eicosatrienoic Acid / Q000031:analogs & derivatives / Q000097:blood*; D001095:Arachidonic Acids / Q000097:blood*; D001205:Ascorbic Acid / Q000494:pharmacology*; D001206:Ascorbic Acid Deficiency / Q000503:physiopathology; D001792:Blood Platelets / Q000187:drug effects* / Q000378:metabolism; D005231:Fatty Acids, Unsaturated / Q000097:blood*; D006801:Humans; D066298:In Vitro Techniques; D011453:Prostaglandins / Q000097:blood*; D011458:Prostaglandins E / Q000097:blood; D013929:Thromboxane B2 / Q000097:blood
chemical_list: D001095:Arachidonic Acids; D005231:Fatty Acids, Unsaturated; D011453:Prostaglandins; D011458:Prostaglandins E; D013929:Thromboxane B2; D015126:8,11,14-Eicosatrienoic Acid; D001205:Ascorbic Acid