Background. The aims of the present study were
to examine serum activities of peptidases, i.e.
prolyl endopeptidase (PEP) and dipeptidyl peptidase IV (DPP IV), in patients
and to examine the effects of subchronic treatment with sertraline on these
Method. Serum PEP and DPP IV activity were measured in 28 normal
volunteers and 21
fibromyalgia patients, classified according to the American College of
Tenderness at tender points was evaluated by means of dolorimetry. Fibromyalgia
repeated measurements of serum PEP and DPP IV both before and after repeated
of sertraline or placebo for 12 weeks.
Results. Patients with fibromyalgia had significantly
lower serum PEP activity than normal
volunteers. There were significantly negative correlations
between serum PEP activity and severity
of pressure hyperalgesia and the non-somatic, cognitive symptoms of the
Rating Scale. Fibromyalgia patients with severe pressure
hyperalgesia had significantly lower PEP
activity than normal controls and fibromyalgia patients with
less severe hyperalgesia. Fibromyalgia
patients with severe non-somatic depressive symptoms had significantly
lower serum PEP activity
than normal volunteers. There were no significant changes in serum DPP
IV activity in
fibromyalgia. There were no significant effects of repeated
administration of sertraline on serum
PEP and DPP IV activity in patients with fibromyalgia.
Conclusions. The results show that fibromyalgia, and aberrant
pain perception and depressive
symptoms in fibromyalgia are related to lower serum PEP activity. It is
hypothesized that lower
serum PEP activity may play a role in the biophysiology of fibromyalgia
inactivation of algesic and depression-related peptides.