Neuroendocrine and Immune Responses to Acute Endotoxemia in Suckling and Weaned Piglets

Abstract

The objective of this study was to characterize effects of weaning stress on behavioural, endocrine and immune responses to acute peripheral lipopolysaccharide (LPS) challenge in neonatal pigs. Weaning in 28-day-old piglets was accompanied by a significant increase in ACTH concentrations (p = 0.0378) and an increase in basal cortisol level (p = 0.0135). There was also a significant suppressive effect on lymphocyte proliferation in response to concanavalin A (p = 0.0048) in newly weaned piglets. Peripheral administration of LPS induced vomiting, diarrhoea and somnolence in both suckling and weaned piglets. The frequency of these signs of sickness was significantly higher in weaned piglets compared with suckling piglets (p = 0.0049). Additionally, LPS significantly increased plasma concentrations of TNF-α, cortisol and ACTH. While weaned piglets reacted to LPS with a higher release of ACTH (p = 0.0239) and cortisol (p = 0.0015) than suckling piglets there was no significant effect of weaning on the magnitude of TNF-α. The present data indicate that weaning suppresses the lymphocyte function, causes changes in endocrine regulation and has a substantial effect on the behavioural and endocrine response to an acute peripheral LPS challenge; consequently it could increase disease susceptibility.

In vivo porcine lipopolysaccharide inflammation models to study immunomodulation of drugs

“…or i.m. (Webel et al, 1997;Kanitz et al, 2002;Tuchscherer et al, 2004;Frank et al, 2005;Llamas Moya et al, 2006). With the exception of the study of Webel et al (1997), sampling each pig only once, these latter studies performed blood sampling by recurrent venipuncture of the LPS-challenged pigs.…”

A Cytokine-Based Neuroimmunologic Mechanism of Cancer-Related Symptoms

“…LPS administered intraperitoneally also induces vomiting in piglets. This response is accompanied by increased circulating levels of TNF-· [69] and blocked by bilateral vagotomy and by COX inhibitors [68].…”

Neuroendocrine-immune correlates of circadian physiology: studies in experimental models of arthritis, ethanol feeding, aging, social isolation, and calorie restriction

“…Available information indicates that psychosocial events like social isolation affect primarily T lymphocytes, and less B lymphocytes [185][186][187][188]. For example, social isolation of pigs in the first days of life caused a significant decrease in immune reactivity at day 12, as assessed by Tcell mitogenesis (Con A response) without affecting Blymphocyte proliferation induced by LPS [189].…”