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Table 4 Symbols used in the text

From: Origin of the blood hyperserotonemia of autism

Symbol

Definition

C p

Numerical concentration of platelets in the blood

C s

Amount of 5-HT per platelet (platelet 5-HT concentration)

D

Diffusion coefficient of 5-HT diffusion from the gut wall into gut blood capillaries

d b

Rate constant of 5-HT influx into the blood due to 5-HT diffusion from the gut

d g

Rate constant of 5-HT loss in the gut due to 5-HT diffusion into the blood

F = F(t)

Flow of free 5-HT in the aorta as a function of time

F ∧ MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacPC6xNi=xH8viVGI8Gi=hEeeu0xXdbba9frFj0xb9qqpG0dXdb9aspeI8k8fiI+fsY=rqGqVepae9pg0db9vqaiVgFr0xfr=xfr=xc9adbaqaaeGaciGaaiaabeqaaeqabiWaaaGcbaGafmOrayKbaKaaaaa@2CFA@

Steady-state flow of free 5-HT in the aorta

G 0

Theoretical concentration of extracellular 5-HT in the gut wall around which the control of gut 5-HT release is near-linear

G = G(t)

Extracellular 5-HT concentration in the gut wall as a function of time

G ∧ MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacPC6xNi=xH8viVGI8Gi=hEeeu0xXdbba9frFj0xb9qqpG0dXdb9aspeI8k8fiI+fsY=rqGqVepae9pg0db9vqaiVgFr0xfr=xfr=xc9adbaqaaeGaciGaaiaabeqaaeqabiWaaaGcbaGafm4raCKbaKaaaaa@2CFC@

Steady-state extracellular 5-HT concentration in the gut wall

k g

5-HT uptake rate constant in the gut wall

k p

5-HT uptake rate constant in blood platelets

N tot

Total number of platelets

R 0

Theoretical, steady-state gut 5-HT release rate achieved when Îħ = β = 0

R = R(t)

Gut 5-HT release rate as a function of time

R ∧ MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacPC6xNi=xH8viVGI8Gi=hEeeu0xXdbba9frFj0xb9qqpG0dXdb9aspeI8k8fiI+fsY=rqGqVepae9pg0db9vqaiVgFr0xfr=xfr=xc9adbaqaaeGaciGaaiaabeqaaeqabiWaaaGcbaGafmOuaiLbaKaaaaa@2D12@

Steady-state gut 5-HT release rate

P 0

Theoretical 5-HT concentration in blood platelets around which the control of gut 5-HT release is near-linear

P ∧ MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacPC6xNi=xH8viVGI8Gi=hEeeu0xXdbba9frFj0xb9qqpG0dXdb9aspeI8k8fiI+fsY=rqGqVepae9pg0db9vqaiVgFr0xfr=xfr=xc9adbaqaaeGaciGaaiaabeqaaeqabiWaaaGcbaGafmiuaaLbaKaaaaa@2D0E@

Steady-state platelet 5-HT concentration

S

Total surface of the blood capillaries in the gut wall

Q tot

Total cardiac output

t

Time

t 1/2

Half-life of blood platelets

u ÂŻ MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacPC6xNi=xH8viVGI8Gi=hEeeu0xXdbba9frFj0xb9qqpG0dXdb9aspeI8k8fiI+fsY=rqGqVepae9pg0db9vqaiVgFr0xfr=xfr=xc9adbaqaaeGaciGaaiaabeqaaeqabiWaaaGcbaGafmyDauNbaebaaaa@2D60@

5-HT uptake rate of an "average" blood platelet

T

Period of blood circulation

w

Wall thickness of gut capillaries

z g

Proportion of cardiac output routed to the gut and/or liver

z ng

Proportion of cardiac output not routed to the gut and/or liver

Îħ

Gain of the gut 5-HT release control that monitors the extracellular 5-HT concentration in the gut wall

β

Gain of the gut 5-HT release control that monitors the 5-HT concentration in platelets

γ

SERT activity

θ h

1- proportion of free 5-HT cleared by the liver in one blood circulation cycle (Fig. 1)

θ p

1- proportion of free 5-HT cleared by the lungs in one blood circulation cycle (Fig. 1)

θ v

1- proportion of free 5-HT cleared by the vascular beds of the "non-gut" system (Fig. 1)

ρ

Surface area of blood capillaries per unit volume of the gut wall

σ

Proportion of blood volume not occupied by cells

τ

Time constant of the decay of platelet numbers due to their aging

Îİ b

Total volume of circulating blood

Îİ g

Total volume of the gut wall

  1. Only symbols used throughout the text are listed. Their precise definitions are given in the text.