Immunohistochemical detection of endogenous opioids enkephalins in dura mater

Patogeneza migrene danas se tumači trima teorijama: hiperpodražljivosti mozga, vaskularnim i trigeminovaskularnim promjenama. Vaskularna i trigeminovaskularna teorija uključuju patološke promjene na razini krvnih žila i živaca koji inerviraju tvrde moždane ovojnice. Trigeminalna bol potiče lučenje endogenih opioida, važnih komponenti endogenog analgezijskog sustava, koji djeluju prvenstveno putem μ opioidnih receptora i smanjuju glavobolju. Primijećeno je također da jaki opioidni agonist morfin djelujući putem μ opioidnih receptora smanjuje stupanj duralne vazodilatacije i sprječava lučenje važnog neuropeptida CGRP-a koji promovira neurogenu upalu dure. S obzirom na povezanost promjena u moždanim ovojnicama, opioidnog sustava i migrene, cilj ovog diplomskog rada bio je ispitati prisutnost endogenih opioida enkefalina u duri mater štakora. Imunohistokemijskom metodom ispitala se prisutnost neurona koji sadrže enkefaline u usporedbi s neuronima koji sadrže CGRP, kao pozitivnom kontrolom. Rezultati ovog istraživanja nisu pokazali prisutnost enkefalina u duri mater. Ovaj negativan rezultat ne isključuje u potpunosti prisutnost opioidnih peptida u tkivu dure već je poticaj na razmišljanje o drugačijim pristupima u njihovoj detekciji, što će biti predmet daljnjih istraživanja.There are three theories of interpretation of migraine pathogenesis today: cerebral hyperexcitability, vascular and trigeminovascular changes. Vascular and trigeminovascular theories include pathological changes in blood vessels and nerves that innervate dura mater. Trigeminal pain induces the release of endogenous opioids, important components of endogenous analgesia system, which interact primarily with μ opioid receptors and decrease headache. It was also noticed that strong opioid agonist morphine reduces the degree of meningeal vasodilatation and inhibits release of important neuropeptide CGRP, which promotes neurogenic inflammation of dura mater, via μ opioid receptors. Considering the relationship between changes in dura mater, opioid system, and migraine, the aim of this thesis was to explore the presence of endogenous opioids enkephalins in dura mater of rats. Using an immunohistochemical method, the presence of enkephalin-containing neurons was examined compared to CGRP containing neurons,as a positive control measure. The results of this research did not show the presence of enkephalins in dura mater. This negative result does not entirely exclude the presence of opioid peptides in the tissue of dura mater but leads to critical thinking about different approaches in their detection which will be subject to further researches