Effects on functions of ovine blood mononuclear cells for each of several fatty acids at concentrations found in plasma of healthy and ketotic ewes.
OBJECTIVE
To assess effects on functions of peripheral blood mononuclear cells (PBMC) obtained from ewes for each of several fatty acids represented in ovine plasma at concentrations mimicking those of ketotic or healthy ewes.


METHODS
Blood samples obtained from 6 Sardinian ewes.


METHODS
The PBMC were cultured in media that contained oleic (OA), palmitic (PA), stearic (SA), linoleic (LA), or palmitoleic (POA) acid at concentrations similar to those of ketotic or healthy ewes. Synthesis of DNA was stimulated by use of concanavalin A or pokeweed mitogen (PWM). Secretion of IgM was stimulated by use of PWM.


RESULTS
High concentrations (900, 450, and 225 micromol/L) of OA significantly inhibited DNA synthesis and IgM secretion of PBMC. Conversely, low concentrations (56 or 28 micromol/L) of OA significantly enhanced DNA synthesis of PBMC. High concentrations of PA (600, 300, 150, 75, 375, or 18.7 micromol/L) and SA (300, 150, or 75 micromol/L) significantly inhibited DNA synthesis of PBMC. High concentrations of PA (600, 300, 150, 75, 375, or 18.7 micromol/L) and SA (300, 150, 75, or 38 micromol/L) also significantly inhibited IgM secretion of PBMC. None of the concentrations of LA and POA affected PBMC functions.


CONCLUSIONS
Impaired immunoresponsiveness of ketotic ewes is likely associated with an increase of plasma concentrations of OA, PA, or SA and not with that of LA or POA. At physiologic concentrations, single fatty acids are likely to participate in modulation of immunoresponsiveness by exerting suppressive or stimulatory effects on immune cells.
Dipartimento di Produzioni Animali, Università degli Studi della Tuscia, Viterbo, Italy.
Nicola
N
Lacetera
Ombretta
O
Franci
Daniela
D
Scalia
Umberto
U
Bernabucci
Bruno
B
Ronchi
Alessandro
A
Nardone
D000818:Animals; D003208:Concanavalin A / Q000378:metabolism; D004247:DNA / Q000096:biosynthesis; D005227:Fatty Acids / Q000097:blood*; D005260:Female; D007075:Immunoglobulin M / Q000096:biosynthesis; D007662:Ketosis / Q000097:blood / Q000378:metabolism / Q000662:veterinary*; D007963:Leukocytes, Mononuclear / Q000378:metabolism*; D011043:Pokeweed Mitogens / Q000378:metabolism; D012756:Sheep / Q000097:blood*; D012757:Sheep Diseases / Q000097:blood*
D005227:Fatty Acids; D007075:Immunoglobulin M; D011043:Pokeweed Mitogens; D003208:Concanavalin A; D004247:DNA