cyclic-gmp and Tension-Type-Headache

The most important primary headaches (i.e. independent disorders that are not caused by another disease) are migraine, tension-type headache and cluster headache. All primary headaches are in need of better treatments. Migraine has a prevalence of 10% in the general population and its societal costs are high. Although the precise mechanisms underlying the pathophysiology of migraine are still elusive, the last decades have witnessed some progress (e.g. involvement of serotonin, calcitonin gene-related peptide, nitric oxide, etc). Nitric oxide (NO) is a very important molecule in the regulation of cerebral and extra cerebral cranial blood flow and arterial diameters. It is also involved in nociceptive processing. Glyceryl trinitrate (GTN), a pro-drug for NO, causes headache in normal volunteers and a so called delayed headache that fulfils criteria for migraine without aura in migraine sufferers. Blockade of nitric oxide synthases (NOS) by L-NMMA effectively treats attacks of migraine without aura. Similar results have been obtained for chronic tension-type headache and cluster headache. Inhibition of the breakdown of cGMP also provokes migraine in sufferers, indicating that cGMP is the effector of NO-induced migraine. Several relationships exist between NO, calcitonin gene-related peptide and other molecules important in migraine. Also ion channels, particularly the K(ATP) channels, are important for the action of NO. In conclusion, inhibition of NO production or blockade of steps in the NO-cGMP pathway or scavenging of NO may be targets for new drugs for treating migraine and other headaches. Indeed, selective n-NOS and i-NOS inhibitors are already in early clinical development.

Topics: Animals; Calcitonin Gene-Related Peptide; Cluster Headache; Cyclic GMP; Drug Delivery Systems; Humans; Ion Channels; Migraine Disorders; Nitric Oxide; Nitric Oxide Synthase Type I; Nitric Oxide Synthase Type II; Tension-Type Headache

Previous research of our group demonstrated an increase in L-arginine/nitric oxide (NO) pathway activity in patients with chronic daily headache (CDH) with a previous history of migraine, which was associated with a reduced platelet serotonin content and increased Ca(2+) levels. In the present work, we assessed the variations in L-arginine/NO pathway activity and platelet cyclic guanosine 3',5'-monophosphate (cGMP) levels in 25 patients affected by chronic tension-type headache (CTTH) (8 M, 17 F; age range: 34-54 years). The NO production, shown spectrophotometrically by stoichiometric transformation of oxyhemoglobin to methemoglobin due to NO synthase (NOS) activity, and inter platelet cGMP concentration, assessed with a RIA method, were determined in parallel to variations of aggregation response to 0.3 microg/ml collagen. The intracellular platelet calcium concentrations were also determined using fluorescence polarisation spectrometry. Platelet serotonin content and collagen-induced secretion as well as glutamate content were also determined with high-performance liquid chromatography (HPLC). The above parameters were compared with those of an age-matched control group. A reduction in aggregation platelet response was found. The reduction in platelet aggregation was coupled with an increased NO and cGMP production (p<0.0002 and p<0.001, respectively). A significant increase in cytosolic Ca(2+) concentration was also detected compared to control individuals (p<0.001). This was accompanied by a reduced platelet content and collagen-induced secretion of serotonin and increased content of glutamate (p<0.0001, p<0.0001 and p<0.001, respectively). The above findings were more evident in patients with analgesic abuse. It can be hypothesized that the increased NOS activity shown in platelets of CTTH patients reflects an analogous central up-regulation of NOS activity in the spinal horn/trigeminal nucleus and supraspinal structures involved in the modulation of nociceptive input from myofascial cranial structures contributing to central sensitization. The increase in NOS activity seems to be associated with a hyposerotonergic status, particularly in patients with analgesic abuse, and this can contribute to central sensitization in CTTH patients. The increase in platelet glutamate content in the same patients suggests the implication of the above excitatory amino acid in spinal and supraspinal structures involved in head pain induction and maintenance.

Topics: Adult; Arginine; Blood Platelets; Calcium; Chronic Disease; Collagen; Cyclic GMP; Cytosol; Female; Glutamic Acid; Humans; Male; Middle Aged; Nitric Oxide; Platelet Aggregation; Reference Values; Serotonin; Tension-Type Headache

Decreased serum and intracellular levels of magnesium have been reported in patients with migraine. It has been suggested that magnesium may play an important role in the attacks and pathogenesis of headaches. We measured ionized magnesium, cyclic AMP (adenosine monophosphate), and cyclic GMP (guanosine monophosphate) in platelets of patients with migraine, in patients with tension-type headache, and in healthy controls. The platelet level of ionized magnesium from patients with tension-type headache was significantly lower than the levels from the other two groups. The platelet level of cyclic AMP from patients with migraine was higher than those from the other groups. We found no significant differences in the platelet cyclic GMP levels among the three groups. It is suggested that reduced platelet ionized magnesium in patients with tension-type headache is related to abnormal platelet function, and that increased platelet cyclic AMP in patients with migraine is related to alteration of neurotransmitters in the platelet.

Topics: Adolescent; Adult; Blood Platelets; Cyclic AMP; Cyclic GMP; Female; Humans; Ions; Magnesium; Male; Middle Aged; Migraine Disorders; Tension-Type Headache