| Overview Topics |
Chemical concentrations and conversions
|
Molecule Type
|
Molecular weight |
Conversion: 1pg/ml converts to |
Conversion: 1 nM converts to |
|
Amyloid-Beta |
3-4 kD |
2.84 x 10 - 4 nM |
3520 pg/ml |
|
IL-1 beta |
17 kD |
5.85 x 10 - 5 nM |
17100 pg/ml |
|
IL 6 |
26 kD |
3.83 x 10 - 5 nM |
26110 pg/ml |
|
TNF-alpha |
17kD |
5.85 x 10 - 5 nM |
17100 pg/ml |
Pharmacological specificity of IL-1alpha (100 pM) binding to
mouse hippocampus (from [4]).
|
Peptide
|
Biological activity [U*/mg] | |
|
IL-1alpha |
3.1 X 107 | |
|
IL-1beta |
2.0 X 107 | |
|
IL-1beta+ |
1.0 X 106 | |
|
Human TNF |
8.0 X 102 | |
|
Rat/human CRF |
0.0 | |
* 1U activity = the amount required for half-maximal induction of
cell proliferation (see [4]).
** These conversions are done as follows:
1 [pg/ml] x [1000 ml / L] x [10 - 12 g / pg] x [ 1 kDa / (1.67 x 10 - 21) gm] x [ 1 molecule / (weight in kDa) ]
x [1 M / 6.02 x 10 23 molecules] x [10 9 nM / M] = [ 9.95 x 10 - 4 / (mol weight) ] nM
Chemical secretion rates and concentrations
|
Molecule Type
|
Molecular weight |
Typical Concentration |
Ref |
|
Amyloid-Beta |
3-4 kD |
0-100 nM |
|
|
IL-1 beta |
17 kD |
2 pg/ml (control) 12 pg/ml (AD brain) |
[5] |
|
IL 6 |
26 kD |
0.2 pg/ml (control) 0.6 pg/ml (AD brain) |
[5] |
|
TNF-alpha |
17kD |
18.8 pg/ml (control) 300 pg/ml (AD brain) |
[1] |
Note: Sometimes international activity units, U, are used. For IL-6, 1 ng/ml = 100 U/ml.
Cytokine secretion amounts and rates
|
Type
|
Amounts secreted by microglia in response to LPS |
Comments |
Ref |
|
IL-1 beta |
300 pg |
(inside cells) 0.2 x10 6 cells for 4 hrs |
[2] |
|
IL 6 |
2000 pg |
0.2 x10 6 cells for 4 hrs |
[2] |
|
TNF-alpha |
400 pg |
0.2 x10 6 cells for 4 hrs |
[2] |
|
Type
|
Rate secreted per microglial cell in response to LPS |
Comments |
|
IL-1 beta |
0.366 nM / min |
Computed as shown below |
|
IL 6 |
1.6 nM / min |
" |
|
TNF-alpha |
0.488 nM /min |
" |
Computed as a local concentration change assuming that cell secretes substance into an adjoining volume, V = (10 microns) 3 . To convert the pg in this volume into pg/ml we do the following:
1 [pg / V] x [V / (10 micron)3] x ([104 micron / cm])3 x [1 cm3 / ml] = 109 pg/ml.
If there are n cells secreting for a time duration d hrs, and using the conversion factor c from above, the concentration change in the given volume per minute will be:
1 [(pg/V) / (n cells)] x [109 (pg/ml) / (pg/V)] x [ 1 / (d hr)] x [c nM/(pg/ml) ] x [ 1hr / 60 min ]
= (109/60 ) c / (d n) nM/min per cell
|
Type
|
Amounts secreted by astrocytes in response to IL-1beta |
Comments |
Ref |
|
IL 6 |
250 pg |
0.2 x10 6 cells for 8 hrs |
[2] |
|
TNF-alpha |
80 pg |
0.2 x10 6 cells for 8 hrs |
[2] |
|
Type
|
Rate secreted per astrocyte cell in response to IL-1beta |
Comments |
|
IL 6 |
0.100 nM / min |
Computed as shown above |
|
TNF-alpha |
0.049 nM /min |
" |
(C) Monocytes
|
Type
|
Amount secreted by monocytes in response to A-beta |
Comments |
Ref |
|
IL 6 |
0-150 pg |
5 x10 6 cells for 48 hrs |
[3] |
|
TNF-alpha |
0-1500 pg |
5 x10 6 cells for 48 hrs |
[3] |
|
Type
|
Secretion rate per monocyte cell in response to A-beta |
Comments |
|
IL 6 |
0-0.399 x 10 - 3 nM / min |
Computed as above |
|
TNF-alpha |
0-6.09 x 10 - 3 nM / min |
References