Submitted to: Journal of Animal Science
Publication Type: Abstract Only
Publication Acceptance Date: 3/12/1997
Publication Date: N/A
Technical Abstract: A study was conducted to determine the effects of several stress-related compounds on porcine (p) lymphocyte function. Porcine peripheral blood lymphocytes (PBL) were isolated and suspended in liquid media. Aliquots of the PBL suspension were cultured in microtiter plate wells with or without the addition of the mitogens Concanavalin A or phytohemagglutinin. In addition, cells were treated with endogenous opioid peptides (EOP; pbeta-endorphin, met-enkephalin, and leuenkephalin, 0-100 ng/well), cannabinoids (anandamide, 0-333 ug/well; WIN 55212-2, 0-50 ug/well; and palmitoylethanolamide, 0-80 ug/well), cortisol (0-.5 ng/well) and ovine prolactin (oPRL, 0-.2 ng/well). All combinations of mitogens and stress-related compounds were replicated in triplicate. PBL function was assessed by the proliferative response to the mitogens and stress hormone treatments. After 48-72 h of incubation, proliferation was terminated and cell numbers were determined by colorimetric analysis. As expected, cortisol decreased basal and mitogen-induced lymphocyte proliferation in a dose dependent manner (P<.01). Likewise, the cannabinoids anandamide (P<.05) and WIN 55,212-2 (P<.01), as well as oPRL (P<.01) suppressed lymphocyte proliferation showing dose dependence. None of the EOP compounds affected basal or mitogen-stimulated proliferation (P>.2). This lack of effect indicates that these peptides either have no effect on cell proliferation, or that the dosage was insufficient to cause an effect. Overall, these results demonstrate that cortisol and cannabinoids, both stress-related compounds, have suppressive effects on porcine lymphocyte function.