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The effects of different acute stressors on LH secretion and their possible interactions with opioidergic and catecholaminergic-modulation of LH secretion were investigated using gonadectomized male miniature pigs. Nose-snare (NS) or high intensity cracker blast (CB) or ACTH (1 iu/kg BW) was administered 3h after start of blood sampling. Animals also received either naloxone (Nal; 1 mg/kg BW) or propranolol-a beta-adrenergic antagonist (Pro; 0.5 mg/kg BW) or saline. Naloxone and propranolol were given 30 (Nal) or 15 min (Pro), before the application of stressor or ACTH. Blood samples were collected every 10 min for 6h. Neither the acute stress of NS nor CB altered the LH secretion. ACTH increased the mean plasma LH concentrations and the LH pulse amplitude (p< or =0.01) but not the pulse frequency. Naloxone elevated the mean LH values in controls, but had no effects on LH pulse frequency or pulse amplitude. Naloxone-induced increase in LH concentrations was attenuated by NS and ACTH. There was an increase in mean plasma LH values (p< or =0.05), LH pulse amplitude (p< or =0.01) and pulse frequency (p< or =0.05) after treatment with propranolol. Nose-snare caused a reduction in the propranolol-induced increase of LH pulse frequency and pulse amplitude. In conclusion, although, the transient painful stress of NS does not affect the LH values, it alters the opioidergic and catecholaminergic-modulation of LH secretion. The interference with opioid system is possibly mediated by ACTH., (Copyright (c) 2010 Elsevier B.V. All rights reserved.)

Exposure to bacterial DNA generates a "danger signal" that stimulates cellular elements of the mammalian immune system to proliferate and/or secrete cytokines. Stimulation is critically dependent on hexameric motifs that contain an unmethylated CpG dinucleotide: these are commonly found in bacterial but not vertebrate DNA. Different motifs are optimally stimulatory in different species. This work examines whether oligodeoxynucleotides (ODNs) containing CpG motifs stimulate peripheral blood mononuclear cells from pigs. Results show that pigs respond to CpG ODN by proliferating and secreting IL-6, IL-12 and TNF-alpha. By screening a large panel (>100) of ODNs, the palindromic hexamer 'ATCGAT' was identified as being optimally active in all animals examined (N=10). These findings are the first to establish the immunostimulatory activity of CpG ODN in pigs, and suggest that the therapeutic uses envisioned for these ODNs (as vaccine adjuvants and immunoprotective agents) may be applicable to husbandry animals.