doktorska disertacija
Povzetek
Osrednji namen te doktorske naloge je bil raziskati nevrotoksični potencial izbranih nanomaterialov (NM), srebra, cerijevega (IV) oksida in titanovega dioksida, pri dveh kopenskih nevretenčarjih, medonosni čebeli Apis mellifera carnica in enakonožcu Porcellio scaber. Organizma smo izpostavili v kroničnih prehranjevalnih testih, v katerih smo spremljali preživetje in prehranjevalno vedenje, izbirno/izogibalno ter druge spremembe v vedenju. Po izpostavitvi organizmov so sledile analize izbranih biokemijskih biomarkerjev, adsorbcije NM na telesno površino pri čebelah in celokupne elementarne koncentracije v enakonožcih. Nevrotoksični potencial NM smo spremljali s študijo holinergičnega sistema, ki je pomemben živčni prenašalni sistem pri čebelah in enakonožcih. Natančneje, spremljali smo aktivnost encima acetilholinesteraze (AChE) v vodi-topni in detergentu-topni frakciji v tkivnih homogenatih iz 3 telesnih kompartmentov čebel (glav, trupov in vzorcev hemolimfe) in v celih enakonožcih z odstranjenim zadnjim črevesom. Pri čebelah smo izvedli dodatno karakterizacijo AChE in vivo z uporabo diazinona, ki je specifični inhibitor AChE z znanim mehanizmom delovanja; ter in vitro z metodo nativne poliakrilamidne gelske elektroforeze v nedenaturirajočih pogojih in specifičnega barvanja AChE. Ker večina kovinskih in kovinskih oksidnih NM lahko povzroči oksidativni stres, smo analizirali aktivnost encima glutation S-transferaze, ki je pokazatelj razstrupljevalnih procesov. Analizirali smo tudi vsebnost proteinov kot pokazatelja metabolnega stanja organizma zaradi energetsko zahtevnih kompenzatornih in razstrupljevalnih mehanizmov. S testnima organizmoma smo izvedli tudi različne vedenjske teste, v katerih smo z možnostjo sočasne izbire med neonesnaženo in onesnaženo hrano ali prstjo (le pri enakonožcih) preizkušali prehranjevalno in raziskovalno vedenje, testirali sposobnost zaznave onesnažene hrane ali prsti in sposobnost izbire med neonesnaženo in onesnaženo hrano ali prstjo (t.j. preference ali izogibanja).
Ključne besede
nevrotoksičnost;nanomateriali;biomarkerji;acetilholinesteraza;strupenostni test;izbirno vedenje;nano srebro;nano cerijev (IV) oksid;nano titanov dioksid;medonosna čebela;Apis mellifera carnica;enakonožci;Porcelio scaber;solinski raki;Artemia sp.;disertacije;
Podatki
Jezik: |
Slovenski jezik |
Leto izida: |
2018 |
Tipologija: |
2.08 - Doktorska disertacija |
Organizacija: |
UL BF - Biotehniška fakulteta |
Založnik: |
[M. Kos] |
UDK: |
620.3:615.9:502/504(043.3)=163.6 |
COBISS: |
920695
|
Št. ogledov: |
9194 |
Št. prenosov: |
963 |
Ocena: |
0 (0 glasov) |
Metapodatki: |
|
Ostali podatki
Sekundarni jezik: |
Angleški jezik |
Sekundarni naslov: |
ǂThe ǂneurotoxicity of selected engineered nanomaterials for model invertebrates |
Sekundarni povzetek: |
The aim of this doctoral dissertation was to investigate neurotoxic potential of selected nanomaterials (NMs), silver, cerium (IV) oxide, and titanium dioxide, in two terrestrial invertebrates, honey bee Apis mellifera carnica and isopod Porcellio scaber. Organisms were exposed in chronic feeding tests, in which survival, feeding behaviour, avoidance, and other behavioral changes were monitored. Exposure was followed by additional analyses of selected biochemical biomarkers, surface adsorption of NMs (honey bees) and total elemental body concentration (isopods). Neurotoxic potential of NMs was studied through the effect on the cholinergic system, which is important neurotransmitter system in honey bees and isopods. More specifically, we analysed the activity of enzyme acetylcholinesterase (AChE) in salt-soluble and detergent-soluble fractions in different body compartments of honey bees (heads, thoraces, and haemolymph) and in whole isopods. In honey bees additional characterisation of AChE was performed in vivo with the use of specific AChE inhibitor diazinon; as well as in vitro with the use of native polyacrylamide gel electrophoresis in non-denatured conditions followed by specific AChE staining. Most metal and metal oxide NMs can cause oxidative stress therefore the activity of glutathione S-transferase was analysed as biomarker of detoxication. Additionally, protein content was analysed to assess the metabolic state of organisms due to energy-demanding compensatory and detoxication mechanisms. Finally, different behavioral tests were carried out with both test organisms, in which they were given a simultaneous choice between two qualities of the food or soil (isopods). With these tests we tested the exploratory and feeding behaviour of both organisms, as well as their ability to detect contaminated food or soil (isopods) and to select between untreated and contaminated food or soil (isopods) (that is to show preference or avoidance towards tested chemical). |
Sekundarne ključne besede: |
neurotoxicity;nanomaterials;biomarkers;acetylcholinesterase;toxicity test;selection behaviour;nano silver;nano cerium (IV) oxide;nano titanium dioxide;honey bee;Apis mellifera carnica;isopod;Porcelio scaber;brine shrimp;Artemia sp.;dissertations; |
Vrsta dela (COBISS): |
Doktorsko delo/naloga |
Študijski program: |
0 |
Konec prepovedi (OpenAIRE): |
1970-01-01 |
Komentar na gradivo: |
Univ. v Ljubljani, Biotehniška fak. |
Strani: |
XVIII, 236, [41] str. |
ID: |
10925889 |