Are leukotrienes cytokines? - Summary

eboyd at eboyd at
Tue Jan 31 10:53:37 EST 1995

The following is a summary of responses  to my question 'Are leukotrienes cytokines?'

Thanks to all who responded!

eboyd at


The leukotrienes are related to prostaglandins, and are not part of the 
cytokine family. Currently, we are up to Interleukin 15 (and counting), with 
some other growth factors and interferons thrown in for good measure. Hope 
this helps.

No , the LTs are not cytokines, but are produced in response to 
cytokine binding to its receptor (at least in the system I work 
on--IL-3 or GM-CSF binds to receptors and my myeloid cells kick out 
of G0/G1 and move into S phase).

Can't help on old-time name for LTB4 (might be slow reacting 
substance of anaphylaxis, but that might be one of the other LTs).

Leukotrienes are lipids derived from arachidonic acid via the lipoxygenase
pathway, and cytokines are proteins.

There are a number of textbooks on cytokines.  Many are dated on the day of
publication since the field is so quickly changing.

Academic Press has a book listing cytokines that looks pretty good:

paper (1994) #155143-1 $42  Callard/Gearing

I hope this helps.

Leukotrienes are lipid mediators of inflammation and immune regulation.
They probably also serve as second messengers in some events triggered by
cytokines, but they are not classified as cytokines. LTC4+LTD4+LTE4 are
what used to be called SRS-A (slow-reacting substance of anaphylaxis). On
the other hand, several of the cytokines were initially named by their
function as "... factor".

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