Biomedical Engineering Reference
In-Depth Information
As already discussed, the activation of Cl
channels lead to variety of human
diseases; therefore, the study of their inhibitors is of paramount importance.
The chloride channel blockers can be grouped according to their targets: (1)
agents acting at the neuronal chloride channels; (2) agents acting with chloride
channels in muscle cells; and (3) agents interfering with the channels in epithelial
cells. A brief description of all these groups is as follows.
4.1 Agents Acting at the Neuronal Chloride Channels
(GABA and Glycine Receptors)
So far the well studied GABA receptor channel blockers are picrotoxin - a mixture
of picrotoxinum (1, PTX) and picrotin (2, PTN) - pentylenetetrazole (3, PTZ),
bicuculline (4) and some bicyclic phosphates [
9
,
166
], and the only known glycine
receptor channel blocker is cyanotriphenylborate (5,CTB) [
83
], which can be used
to distinguish receptors containing
a
1
-or
a
2
-subunit, as the
a
2
-subunit is relatively
insensitive to CTB.
O
H
O
CH
3
O
O
H
OH
O
H
2
C
CH
3
1, Picrotoxinin/Picrotoxinum
O
H
O
CH
3
O
O
H
OH
O
H
3
C
CH
3
OH
2, Picrotin
