Emootje
Senior Member
- Messages
- 356
- Location
- The Netherlands
During maximal exercise in healthy humans, blood flow to the gut is reduced by about 80%. This reduction in blood flow could cause an increase in gut permeability whereby endotoxins leaks into the systemic circulation leading to various symptoms, such as fever,shivering, dizziness, nausea, vomiting and diarrhoea. In ME/CFS the gut blood flow is already challenged by low blood volume and sympathetic over-activation. If we exercise this gut blood flow is challenged even further. Now I was wondering whether this gut hypoperfusion is responsible for our PEM symptoms.
"Prolonged exercise at high intensity leads to a quantitative
redistribution of blood flow, i.e. flow to the exercising
muscles is increased in order to supply oxygen and
substrates. In addition, during intense exercise the blood
flow to the skin is increased to facilitate heat dissipation.
As a consequence, blood flow to central tissues (gut and
liver) is reduced during exercise [1,2]. During maximal
exercise in humans, blood flow to the gut is reduced by
about 80% [3]. Exercise in the heat leads to an extra loss
of total body water and a greater decrease in plasma
volume, with further reduction in blood flow to the gut
[4,5]. A similar redistribution of blood flow is seen in
patients with major trauma and/or sepsis and various
forms of shock [6]. In this situation, a serious underperfusion
of the gut often leads to shock-induced mucosal
damage and invasion of Gram-negative intestinal bacteria
and/or their toxic constituents (endotoxins) into the
blood circulation [7]. Endotoxins are highly toxic lipopolysaccharides
(LPS) of the outer cell wall of Gramnegative
bacteria. Increased circulating LPS levels in
patients lead to various symptoms, such as fever,
shivering, dizziness, nausea, various gastro-intestinal
(GI) complaints such as vomiting and diarrhoea, and
ultimately sepsis [8]"
"Not only might decreased splanchnic blood flow lead
to ischaemic damage to the intestinal wall, but there may
also be thermal and mechanical damage to the mucosal
layer of the gut. Gram-negative bacteria, present in the
gut, may then penetrate the mucosal layer and enter
the lymph nodes in the submucosal tissues. This may lead
to the entry of LPS into the portal vein and, under extreme
conditions, even into the main circulation"
http://www.clinsci.org/cs/098/0047/0980047.pdf
"Prolonged exercise at high intensity leads to a quantitative
redistribution of blood flow, i.e. flow to the exercising
muscles is increased in order to supply oxygen and
substrates. In addition, during intense exercise the blood
flow to the skin is increased to facilitate heat dissipation.
As a consequence, blood flow to central tissues (gut and
liver) is reduced during exercise [1,2]. During maximal
exercise in humans, blood flow to the gut is reduced by
about 80% [3]. Exercise in the heat leads to an extra loss
of total body water and a greater decrease in plasma
volume, with further reduction in blood flow to the gut
[4,5]. A similar redistribution of blood flow is seen in
patients with major trauma and/or sepsis and various
forms of shock [6]. In this situation, a serious underperfusion
of the gut often leads to shock-induced mucosal
damage and invasion of Gram-negative intestinal bacteria
and/or their toxic constituents (endotoxins) into the
blood circulation [7]. Endotoxins are highly toxic lipopolysaccharides
(LPS) of the outer cell wall of Gramnegative
bacteria. Increased circulating LPS levels in
patients lead to various symptoms, such as fever,
shivering, dizziness, nausea, various gastro-intestinal
(GI) complaints such as vomiting and diarrhoea, and
ultimately sepsis [8]"
"Not only might decreased splanchnic blood flow lead
to ischaemic damage to the intestinal wall, but there may
also be thermal and mechanical damage to the mucosal
layer of the gut. Gram-negative bacteria, present in the
gut, may then penetrate the mucosal layer and enter
the lymph nodes in the submucosal tissues. This may lead
to the entry of LPS into the portal vein and, under extreme
conditions, even into the main circulation"
http://www.clinsci.org/cs/098/0047/0980047.pdf