Protein tolerance threshold

In the same way as diabetics have their own spedfic glucose tolerance threshold, all cirrhotic patients likewise have their own protein tolerance threshold. 

At this point, we would like to emphasize once again that a strict lactovegetarian protein supply must be adhered to not only in latent encephalopathy, but also in (acute or chronic) liver diseases in which insufficient detoxification of ammonia is anticipated. When assessing the so-called protein tolerance threshold (s. p. 278), the documentation sheet (s. fig. 15.3) as well as a psycho-motoric test programme (s. p. 203) can be of great help. 

At micromolar concentrations opioids cause an increase in the cell membrane threshold, shortened action potentials, and inhibition of neurotransmitter release. At nanomolar concentrations opioid agonists are excitatory and prolong the action potential via the stimulatory G proteins, which act on the adenylate cyclase/cAMP system and on protein kinase A-dependent ion channels. Tolerance is proposed to be the result of an increase in the association of opioid receptors to stimulatory G proteins, to an activation of A-methyl-o-aspartate receptors via protein kinase C, and calmodulin-dependent increases in cytosolic calcium, resulting in cellular hyperexcitability. 

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