The potential role of aminoguanidine against oxidative stress in boar spermatozoa

Bc. Martin Kadlec

Master's thesis

Abstract:

Currently, modern pig reproduction is mainly performed through artificial insemination (AI), which is dependent on the production of high quality semen doses. Due to specific attributes of boar semen, the preparation of insemination doses represents an important challenge. One of such aspects is the unique composition of boar spermatozoa membrane, which contains high amount of polyunsaturated fatty acids (PUFA) making the spermatozoa highly sensitive to reactive oxygen species (ROS). This thesis is the first work dedicated to testing of the antioxidant capacity of aminoguanidine (AG) compound directly supplemented to boar semen samples under induced OS. In order to reduce male variability, the semen was mixed into pool for each of 5 replicates. Totally, semen of 15 boars was used. Oxidative stress was induced by incubating sperm samples with 0.05 mM FeSO4 plus 0.5 mM sodium ascorbate (Fe2+/ascorbate). The aminoguanidine was supplemented at following concentrations: 0.1 mM (Ag0.1-ox), 1 mM (Ag1-ox), and 10 mM. (Ag10-ox) All the samples were incubated at 38°C and evaluated at 2 and 3.5 hours except control sample, which was also evaluated at 0 hour. The assessment of motility included subjective evaluation and measurement of kinetic parameters by CASA. To establish the acrosomal status, normal apical ridge (NAR) test was performed. Moreover, the membrane status was analysed by PI/CFDA and HOST-eosin tests. Motility evaluation showed that AG was most effective at concentrations 1 mM and 10 m. Total sperm motility at 3.5 hours of sample incubation was almost 3 times higher in Ag10-ox than in control oxidised treatment (Ctr-ox). Moreover, several other kinetic parameters were improved in Ag1-ox and Ag10-ox: STR, VAP, VCL and VSL (p>0.05). Remarkably, the last three named parameters were more than two times higher compared to Ctr-ox. Additionally, all samples supplemented with AG showed higher percentage of acrosome and membrane intact sperm cells than Crt-ox (p>0.05). However, host-eosin test was only one that did not demonstrate significant difference between AG treatment and control group. Overall, AG showed substantial antioxidant capacity which resulted in increased motility and membrane integrity of boar spermatozoa under oxidative stress.

Keywords

boar spermatozoa, reactive oxygen species, oxidative stress, aminoguanidine, antioxidant

Language used: English

Date on which the thesis was submitted / produced: 13. 4. 2018

Thesis defence

• Supervisor: Dott. Ric. Eliana Pintus

Czech University of Life Sciences Prague

Faculty of Agrobiology, Food and Natural Resources

Master programme / field:
Genetic Technologies and Breeding / Biotechnology of Reproduction