Moderate hypercapnia-induced anesthetic effects and endogenous opioids.

Denne nevner hvordan hyperkapni (økt CO2) kan virke smertedempende ved at det demper nocieptive aktivering ved hjelp av opioder. Men studien benyttet seg av ganske høy hypercapni, 87mmHg, noe som sannsynligvis er umulig å få til med pustetrening, hvor vi øker det til 45-50mmHg.

http://www.ncbi.nlm.nih.gov/pubmed/16701947

Abstract

The purpose of this report is to explore the mechanisms of hypercapnia-induced antinociception. We carried out three experiments, the first to confirm whether moderate hypercapnia induces anesthetic effects, the second to determine whether naloxone reverses the anesthetic effects, and the third to evaluate whether beta-endorphin is related to the anesthetic effects. In a pre-test, we determined the optimal CO(2) concentration in a chamber which would cause moderate hypercapnia in rats. Eighteen rats were divided into control, hypercapnia, and hypercapnia plus naloxone groups in experiment 1. The naloxone group rats were injected with naloxone (10 mg/kg) intraperitoneally before gas inhalation. After 60 min gas inhalation, 10% formalin was injected into the left rear paw of all rats, and nociceptive behaviors were observed for 1 h. In experiment 2, 11 rats were divided into control and hypercapnia groups. The brain was removed and fixed under pentobarbital anesthesia. Sections were immunostained for c-Fos and beta-endorphin (ACTH) with the ABC method. All neurons double-labeled for c-Fos and beta-endorphin (ACTH) in the arcuate nucleus were counted by blinded investigators. Moderate hypercapnia (PaCO(2) 83+/-7 mmHg) reduced nociceptive behavior in the formalin test and naloxone pre-treatment attenuated this phenomenon. However, beta-endorphin-producing neurons were not activated by CO(2) inhalation. Endogenous opioids are related to moderate, hypercapnia-induced anesthetic effects, but, beta-endorphin-producing neurons in the hypothalamus were not activated by the CO(2) inhalation stress.

The nutriceutical bovine colostrum truncates the increase in gut permeability caused by heavy exercise in athletes

Studie som nevner at hard trening gir lekk tarm, og at Colostrum (hoppemelk) lukker tarmen. Dette kan forklare hvorfor så mange vektløftere og toppidrettsutøver har problemer med tarm og immunsystem. I studien brukte de 20g colostrum daglig, som er ganske mye.

http://ajpgi.physiology.org/content/300/3/G477

Heavy exercise causes gut symptoms and, in extreme cases, “heat stroke” partially due to increased intestinal permeability of luminal toxins. We examined bovine colostrum, a natural source of growth factors, as a potential moderator of such effects. Twelve volunteers completed a double-blind, placebo-controlled, crossover protocol (14 days colostrum/placebo) prior to standardized exercise. Gut permeability utilized 5 h urinary lactulose-to-rhamnose ratios. In vitro studies (T84, HT29, NCM460 human colon cell lines) examined colostrum effects on temperature-induced apoptosis (active caspase-3 and 9, Baxα, Bcl-2), heat shock protein 70 (HSP70) expression and epithelial electrical resistance. In both study arms, exercise increased blood lactate, heart rate, core temperature (mean 1.4°C rise) by similar amounts. Gut hormone profiles were similar in both arms although GLP-1 levels rose following exercise in the placebo but not the colostrum arm (P = 0.026). Intestinal permeability in the placebo arm increased 2.5-fold following exercise (0.38 ± 0.012 baseline, to 0.92 ± 0.014, P < 0.01), whereas colostrum truncated rise by 80% (0.38 ± 0.012 baseline to 0.49 ± 0.017) following exercise. In vitro apoptosis increased by 47–65% in response to increasing temperature by 2°C. This effect was truncated by 60% if colostrum was present (all P < 0.01). Similar results were obtained examining epithelial resistance (colostrum truncated temperature-induced fall in resistance by 64%, P < 0.01). Colostrum increased HSP70 expression at both 37 and 39°C (P < 0.001) and was truncated by addition of an EGF receptor-neutralizing antibody. Temperature-induced increase in Baxα and reduction in Bcl-2 was partially reversed by presence of colostrum. Colostrum may have value in enhancing athletic performance and preventing heat stroke.

SEVERAL STRESSES AFFECT the integrity of the intestinal barrier. These include prolonged strenuous exercise (10), heat stress (11), and drugs such as nonsteroidal anti-inflammatory agents. Loss of intestinal barrier integrity leading to increased intestinal permeability may result in passage of luminal endotoxins into the circulation. This, in turn, results in an inflammatory cascade, exacerbating the loss of barrier function and, in severe cases, resulting in severe systemic effects.

Gastrointestinal symptoms including cramps, diarrhea, nausea, and bleeding are commonly reported by long-distance runners (16). These symptoms are likely to be due to a combination of reduced splanchnic blood flow, hormonal changes, altered gut permeability, and increased body temperature.

Colostrum is the first milk produced after birth and is particularly rich in immunoglobulins, antimicrobial peptides (e.g., lactoferrin, lactoperoxidase), and other bioactive molecules including growth factors (20).

We have previously shown, using a combination of in vitro and in vivo studies, that a commercially available defatted bovine colostral preparation can reduce NSAID-induced upper intestinal gut injury in rats, mice, and humans (19, 21).

The total protein content of the colostrum was 80%. The concentrations of the various growth factors present in the colostrum preparation are incompletely defined but include IGF-I at 213 ng/g, TGF-β1 at 113 ng/g, and TGF-β2 at 441 ng/g.

In a double-blind crossover design, subjects received oral supplementation with 20 g/day bovine colostrum or the isoenergetic and isomacronutrient placebo.

Neurogenic neuroinflammation: inflammatory CNS reactions in response to neuronal activity

Omfattende gjennomgang om hvordan nevrogene betennelser fungerer fysiologisk. Nevner at betennelser ikke er problemet, men en funksjon kroppen benytter seg av for å håndtere problemer som giftstoffer og metabolsk problemer. Derfor nytter det ikke å dempe betennelsen. Man MÅ fjerne årsaken til betennelsen…

http://www.ncbi.nlm.nih.gov/pubmed/24281245

http://www.nature.com/nrn/journal/vaop/ncurrent/full/nrn3617.html

The CNS is endowed with an elaborated response repertoire termed ‘neuroinflammation’, which enables it to cope with pathogens, toxins, traumata and degeneration. On the basis of recent publications, we deduce that orchestrated actions of immune cells, vascular cells and neurons that constitute neuroinflammation are not only provoked by pathological conditions but can also be induced by increased neuronal activity. We suggest that the technical term ‘neurogenic neuroinflammation’ should be used for inflammatory reactions in the CNS in response to neuronal activity. We believe that neurogenic neuro-inflammation maintains homeostasis to enable the CNS to cope with enhanced metabolic demands and increases the computational power and plasticity of CNS neuronal networks. However, neurogenic neuroinflammation may also become maladaptive and aggravate the outcomes of pain, stress and epilepsy.

Carbon dioxide and the critically ill—too little of a good thing?

Omfattende studie av alle de gode egenskapene ved hyperkapni – høyt CO2 nivå. Nevner mange interessante ting, bl.a. at CO2 indusert acidose gir mye mindre fire radikaler enn om pH senkes av andre faktorer. Bekrefter også at oksygen blir sittende fast på blodcellene ved hypokapni, og at melkesyreproduksjonen begrensens når acidosen er pga CO2 men ikke når den er av andre faktorer.

Spesielt med denne artikkelen er at den beskriver forskjellene på en hyperkapni acidose og acidose av andre faktorer. Hyperkapnisk acidose har beskyttende egenskaper.
http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(99)02388-0/fulltext

Permissive hypercapnia (acceptance of raised concentrations of carbon dioxide in mechanically ventilated patients) may be associated with increased survival as a result of less ventilator-associated lung injury.
Accumulating clinical and basic scientific evidence points to an active role for carbon dioxide in organ injury, in which raised concentrations of carbon dioxide are protective, and low concentrations are injurious.
Although hypercapnic acidosis may indicate tissue dysoxia and predict adverse outcome, it is not necessarily harmful per se. In fact, it may be beneficial. There is increasing evidence that respiratory (and metabolic) acidosis can exert protective effects on tissue injury, and furthermore, that hypocapnia may be deleterious.
If hypoventilation is allowed in an effort to limit lung stretch, carbon dioxide tension increases. Such “permissive hypercapnia” may be associated with increased survival in acute respiratory distress syndrome (ARDS);2 this association is supported by outcome data from a 10-year study.3
Furthermore, hypocapnia shifts the oxyhaemoglobin dissociation curve leftwards, restricting oxygen off-loading at the tissue level; local oxygen delivery may be further impaired by hypocapnia-induced vasoconstriction.
Brain homogenates develop far fewer free radicals and less lipid peroxidation when pH is lowered by carbon dioxide than when it is lowered by hydrochloric acid.19
Finally, greater inhibition of tissue lactate production occurs when lowered pH is due to carbon dioxide than when it is due to hydrochloric acid.20
An association between hypoventilation, hypercapnia, and improved outcome has been established in human beings.2521 In lambs, ischaemic myocardium recovers better in the presence of hypercapnic acidosis than metabolic acidosis.22 Hypercapnic acidosis has also been shown to protect ferret hearts against ischaemia,23 rat brain against ischaemic stroke,16 and rabbit lung against ischaemia-reperfusion injury.24 Hypercapnia attenuates oxygen-induced retinal vascularisation,25 and improves retinal cellular oxygenation in rats.26 “pH-stat” management of blood gases during cardiopulmonary bypass, involving administration of large amounts of additional carbon dioxide for maintenance of temperature-corrected PaCO2, results in better neurological and cardiac outcome.27
Hypercapnia results in a complex interaction between altered cardiac output, hypoxic pulmonary vasoconstriction, and intrapulmonary shunt, with a net increase in PaO2 (figure).28 Because hypercapnia increases cardiac output, oxygen delivery is increased throughout the body.28 Regional, including mesenteric, blood flow is also increased,29 thereby increasing oxygen delivery to organs. Because hypercapnia (and acidosis) shifts the haemoglobin-oxygen dissociation curve rightwards, and may increase packed-cell volume,30 oxygen delivery to tissues is further increased. Acidosis may reduce cellular respiration and oxygen consumption,31 which may further benefit an imbalance between supply and demand, in addition to greater oxygen delivery. One hypothesis32 is that acidosis protects against continued production of further organic acids (by a negative feedback loop) in tissues, providing a mechanism of cellular metabolic shutdown at times of nutrient shortage—eg, ischaemia.
Acidosis attenuates the following inflammatory processes (figure): leucocyte superoxide formation,33 neuronal apoptosis,34phospholipase A2 activity,35 expression of cell adhesion molecules,36 and neutrophil Na+/H+ exchange.37 In addition, xanthine oxidase (which has a key role in reperfusion injury) is inhibited by hypercapnic acidosis.24 Furthermore, hypercapnia upregulates pulmonary nitric oxide38 and neuronal cyclic nucleotide production,39 both of which are protective in organ injury. Oxygen-derived free radicals are central to the pathogenesis of many types of acute lung injury, and in tissue homogenates, hypercapnia attenuates production of free radicals and decreases lipid peroxidation.19 Thus, during inflammatory responses, hypercapnia or acidosis may tilt the balance towards cell salvage at the tissue level.
However, we know from several case series that human beings, and animals, can tolerate exceptionally high concentrations of carbon dioxide, and when adequately ventilated, can recover rapidly and completely. Therefore, high concentrations (if tolerated) may not necessarily cause harm.
From the published studies reviewed, and from the pathological mechanisms assessed, we postulate that changes in carbon dioxide concentration might affect acute inflammation,33—36 tissue ischaemia,16 ischaemia-reperfusion,2024 and other metabolic,1221,32 or developmental14 processes.
We argue that the recent shift in thinking about hypercapnia must now be extended to therapeutic use of carbon dioxide. Our understanding of the biology of disorders in which hypocapnia is a cardinal element would require fundamental reappraisal if hypocapnia is shown to be independently harmful.
In summary, in critically ill patients, future therapeutic goals involving PaCO2 might be expressed as:“keep the PaCO2 high; if necessary, make it high; and above all, prevent it from being low”.

Stress and the inflammatory response: a review of neurogenic inflammation.

Betennelser kan både skapes og opprettholdes av nervesystemet.

Det er velkjent av betennelser økes av stresshormonet kortisol når vi stresser fordi kortisol senker immunfunksjon og dermed øker betennelsestilstander.

Men denne studien beskriver hvordan stress øker nevrogen betennelse (betennelse i nervesystemet), som kan forklare årsaken til at alt som vanligvis bare er litt ukomfortabelt blåses opp og blir vondere når vi er i langvarig stress.

Man tenker vanligvis på sansenerver som noe som sender signaler fra kroppen, gjennom ryggraden og opp til hjernen. Men molekyler kan faktisk gå andre veien i nervetrådene også. Fra ryggraden og UT i kroppen. Når vi stresser sender nervecellene ut et stoff som kalles Substans P, sammen med andre betennelsesøkende stoffer. Der hvor nervetrådene ender (i ledd, i huden eller i organer) blir det en lokal betennelsesreaksjon som bidrar til smerte. Substans P er spesielt assosisert med smertetilstander.

Forskeren konkluderer også med at dette er en viktig årsak til hvordan kronisk stress kan bidra til kroniske betennelsessykdommer som arterosklreose i blodårene eller betennelser i organene.

Beste måten å roe ned et stresset nervesystem er meditasjon med Autonom pust (5-6 pust i minuttet).

http://www.ncbi.nlm.nih.gov/pubmed/12480495

The subject of neuroinflammation is reviewed. In response to psychological stress or certain physical stressors, an inflammatory process may occur by release of neuropeptides, especially Substance P (SP), or other inflammatory mediators, from sensory nerves and the activation of mast cells or other inflammatory cells.

Central neuropeptides, particularly corticosteroid releasing factor (CRF), and perhaps SP as well, initiate a systemic stress response by activation of neuroendocrinological pathways such as the sympathetic nervous system, hypothalamic pituitary axis, and the renin angiotensin system, with the release of the stress hormones (i.e., catecholamines, corticosteroids, growth hormone, glucagons, and renin). These, together with cytokines induced by stress, initiate the acute phase response (APR) and the induction of acute phase proteins, essential mediators of inflammation. Central nervous system norepinephrine may also induce the APR perhaps by macrophage activation and cytokine release. The increase in lipids with stress may also be a factor in macrophage activation, as may lipopolysaccharide which, I postulate, induces cytokines from hepatic Kupffer cells, subsequent to an enhanced absorption from the gastrointestinal tract during psychologic stress.

The brain may initiate or inhibit the inflammatory process.

The inflammatory response is contained within the psychological stress response which evolved later. Moreover, the same neuropeptides (i.e., CRF and possibly SP as well) mediate both stress and inflammation.

Cytokines evoked by either a stress or inflammatory response may utilize similar somatosensory pathways to signal the brain. Other instances whereby stress may induce inflammatory changes are reviewed.

I postulate that repeated episodes of acute or chronic psychogenic stress may produce chronic inflammatory changes which may result in atherosclerosis in the arteries or chronic inflammatory changes in other organs as well.

How to make stress your friend

Spennende perspektiv på stress. Nevner at de som trodde at stress var farlig, hadde større sjanse for å dø av det. De som trodde stress ikke var farlig, hadde samme dødelighet som alle andre. Å vite hva stress er kan redde liv. Så neste gang du opplever stress, vit at «dette er kroppen min som hjelper meg å løfte energien til det nivået jeg trenger for å løse problemet», som hun sier i foredaget. Men gi også kroppen mulighet til å ta seg ned noen nivåer igjen når stresset er ferdig.