Insulin ameliorating endotoxaemia-induced muscle wasting is associated with the alteration of hypothalamic neuropeptides and inflammation in rats.

OBJECTIVES: Septic patients always develop muscle wasting, which delays the rehabilitation and contributes to the increased complications and mortality. Previous studies have implied the crucial role of central inflammation and neuropeptides in the energy balance and muscle metabolism. Insulin has been confirmed to attenuate muscle degradation and inhibit inflammation. We tested the hypothesis whether insulin ameliorating muscle wasting was associated with modulating hypothalamic inflammation and neuropeptides. DESIGN AND SUBJECTS: Thirty-two adult male Sprague-Dawley rats were in intraperitoneally injected with lipopolysaccharide (LPS) (5 mg/kg) or saline, followed by subcutaneous injection of insulin (5 IU/kg) or saline. Twenty-four hours after injection, skeletal muscle and hypothalamus tissues were harvested. Muscle wasting was measured by the mRNA expression of two E3 ubiquitin ligases, muscle ring finger 1 (MuRF-1) and muscle atrophy F-box (MAFbx), as well as 3-methylhistidine (3-MH) and tyrosine release. Hypothalamic inflammatory markers and neuropeptides expression were also measured in four groups. RESULTS: LPS injection led to significant increase in hypothalamic inflammation as well as muscle wasting. Also, increased hypothalamic neuropeptides, proopiomelanocortin (POMC), cocaine and amphetamine-related transcript (CART) and neuropeptides Y (NPY) and decreased agouti-related protein (AgRP) were observed. Insulin treatment ameliorated endotoxaemia-induced muscle wasting and hypothalamic inflammation, and attenuated the alteration of neuropeptides, POMC, CART and AgRP. CONCLUSION: Hypothalamic inflammation and neuropeptides are involved in the endotoxaemia-induced muscle wasting. Insulin treatment can reduce muscle wasting, which is associated with reduced hypothalamic inflammation and alteration of hypothalamic neuropeptides.

Inulin controls inflammation and metabolic endotoxemia in women with type 2 diabetes mellitus: a randomized-controlled clinical trial.

There is limited evidence on the effects of prebiotics on inflammation. Therefore, the aim of this study was to evaluate the effects of inulin supplementation on inflammatory indices and metabolic endotoxemia in patients with type 2 diabetes mellitus. The participants included diabetic females (n = 49). They were divided into an intervention group (n = 24) as well as a control group (n = 25) and received 10 g/d inulin or maltodextrin for 8 weeks, respectively. Fasting blood sugar (FBS), HbA1c, insulin, high-sensitive C-reactive protein (hs-CRP), tumor necrosis factor-alpha (TNF-α), interleukin-10 (IL-10), and plasma lipopolysaccharide (LPS) were measured pre and post intervention. Inulin-supplemented patients exhibited a significant decrease in FBS (8.5%), HbA1c (10.4%), fasting insulin (34.3%), homeostasis model assessment of insulin resistance (HOMA-IR) (39.5%), hs-CRP (35.6%), TNF-α (23.1%), and LPS (27.9%) compared with the maltodextrin group (p < 0.05). Increase in IL-10 was not significant in inulin compared with the maltodextrin group. It can be concluded that inulin supplementation seems to be able to modulate inflammation and metabolic endotoxemia in women with type 2 diabetes.

Hemodynamic and metabolic manifestations of acute endotoxin infusion in pigs with and without the malignant hyperthermia mutation.

BACKGROUND: The hypermetabolic state induced by acute endotoxemia and malignant hyperthermia (MH) may be indistinguishable. The aims of this study were (1) to investigate the differences between MH and sepsis, (2) to determine whether acute endotoxemia can trigger MH, and (3) to establish the effects of dantrolene in these two disorders. METHODS: Three groups of swine were studied. All pigs were invasively monitored and initially anesthetized with nontriggering agents. A placebo MH-susceptible group (n = 5) received normal saline whereas the endotoxin groups (MH-susceptible, n = 6; MH-negative, n = 4) received intravenous endotoxin (250 microg/kg total) during 2.5 h. Halothane (1.5%) and succinylcholine (2-4 mg/kg) were then administered, followed by two doses of dantrolene (4 mg/kg total). RESULTS: Endotoxin infusion resulted in pulmonary hypertension and systemic hypotension in pigs with and without the MH mutation, but did not trigger MH. Halothane and succinylcholine triggered MH, evidenced by a markedly higher oxygen consumption in the MH-susceptible pigs that received endotoxin (325+/-196 ml/min) and those that did not (374+/-110 ml/min) compared to the MH-negative pigs (69+/-15 ml/min, P<0.0009), as well as muscular rigidity in the susceptible animals. Dantrolene reversed these changes. Three of the six MH-susceptible pigs that received endotoxin died; two died soon after triggering and one after dantrolene administration. In contrast, none of the MH-negative pigs or the MH-susceptible pigs that did not receive endotoxin died (0 of 9 vs. 3 of 6, P = 0.044). CONCLUSION: Endotoxemia does not trigger MH, but may worsen outcome if it occurs.