Lazarova, Maria
Popatanasov, Andrey
Klissurov, Radoslav
Stoeva, Svetlana
Pajpanova, Tamara http://orcid.org/0000-0001-6278-1816
Kalfin, Reni
Tancheva, Lyubka
Article History
Received: 19 July 2018
Accepted: 13 September 2018
First Online: 30 October 2018
Compliance with Ethical Standards
: The experiments were performed strictly according to the national regulations and European Directive 2010/63/EU of 22 September 2010 concerning the protection of animals used for scientific and experimental purposes.
: The authors declare that they have no conflict of interest.