Penitrem A is a fungal neurotoxin

Neurotoxin

A neurotoxin is a toxin that acts specifically on nerve cells , usually by interacting with membrane proteins such as ion channels. Some sources are more general, and define the effect of neurotoxins as occurring at nerve tissue...

 found on ryegrass

Ryegrass

Ryegrass is a genus of nine species of tufted grasses in the Pooideae subfamily of the Poaceae family. Also called tares , these plants are native to Europe, Asia and northern Africa, but are...

. It is produced by certain species of Aspergillus

Aspergillus

Aspergillus is a genus consisting of several hundred mold species found in various climates worldwide. Aspergillus was first catalogued in 1729 by the Italian priest and biologist Pier Antonio Micheli...

, Claviceps, and Penicillium

Penicillium

Penicillium is a genus of ascomycetous fungi of major importance in the natural environment as well as food and drug production. Members of the genus produce penicillin, a molecule that is used as an antibiotic, which kills or stops the growth of certain kinds of bacteria inside the body...

. It inhibits potassium channel

Potassium channel

In the field of cell biology, potassium channels are the most widely distributed type of ion channel and are found in virtually all living organisms. They form potassium-selective pores that span cell membranes...

s in smooth muscle

Smooth muscle

Smooth muscle is an involuntary non-striated muscle. It is divided into two sub-groups; the single-unit and multiunit smooth muscle. Within single-unit smooth muscle tissues, the autonomic nervous system innervates a single cell within a sheet or bundle and the action potential is propagated by...

s. The maxi-channels targeted have their highest density in the cerebellar Purkinje cells.

It causes a stagger in horses and cattle.

Effective dose

The ED₅₀

Effective dose

Effective dose may refer to:*Effective dose the dose of pharmacologic agent which will have a therapeutic effect in some fraction of the population receiving the drug...

 for penitrem A is 10 nM. The ED₅₀ is the effective dose

Effective dose

Effective dose may refer to:*Effective dose the dose of pharmacologic agent which will have a therapeutic effect in some fraction of the population receiving the drug...

 for 50% of the population. Many toxic chemicals do not show ED-50s and act by irreversible covalent adduction

Adduction

Adduction is a movement which brings a part of the anatomy closer to the middle sagittal plane of the body. It is opposed to abduction.-Upper limb:* of arm at shoulder ** Subscapularis** Teres major** Pectoralis major** Infraspinatus...

.