2016, vol. 66, br. 2, str. 245-256
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Ultrastrukturne poromene cikličnog žutog tela kod muznih krava sa različitim telesnim kondicijama
Ultrastructural changes in the cyclic corpus luteum of dairy cows with different body condition
aResearch Institute for Animal Production Nitra, National Agricultural and Food Centre, Lužianky-near-Nitra, Slovak Republic bUniversity of Ss. Cyril and Methodius in Trnava, Trnava, Slovak Republic cSlovak University of Agriculture, Nitra, Slovak Republic
e-adresa: makarevic@vuzv.sk
Projekat: Project of the Agency for the Support of Science and Technology in the Slovak Republic: grants APVV-0137-10
Project of the Agency for the Support of Science and Technology in the Slovak Republic: grants APVV-14-00-43
Project of the European Community, no. 26220220180: Building Research Centre 'Agro Biotech'
Sažetak
Cilj studije je bio da se definišu ultrastrukturne promene u ovarijalnom ciklusu žutog tela (CL) muznih krava koje su imale različite skorove telesne kondicije (BCS, petostepena skala). Ovarijumi su uzimani sa linije klanja, od holštajn muznih krava koje su imale telesnu kondiciju BCS1 (izražena kaheksija; n=4), BCS2 (tendencija ka kaheksiji, n=4), BCS3 (prosečna telesna kondicija, n=4), BCS4 (tendencija ka tovu; n=4) i BCS5 (utovljene krave; n=4). Prosečno su krave bile starosti: 6.2, 4.1, 5.7, 5.5 i 6.36 godina i to za BCS1, BCS2, BCS3, BCS4 odnosno BCS5. U cilju ispitivanja elektronskom mikroskopijom, funkcionalna CL u sredini lutealne faze, fiksirana su u rastvoru aldehida i posle toga u 1% rastvoru OsO4. Radi vizualizacije lipida, uzorci su potapani u 1% rastvor fenilendiamina u acetonu. Durcupan ultratanki isečci (90nm) su uz upotrebu uranil acetata i olovo citrata, ispitivani upotrebom Jeol transmisionog elektronskog mikroskopa. Pojava ćelijskih organela je ustanovljena brojanjem relativne zapremine pojedinačnih ćelijskih komponenti koristeći metodu modifikovane opšte mreže. Osobine lutealne regresije cikličnog CL bile su atrofija luteinskih ćelija, kondenzacija organela i citoplazmatskih inkluzija, povećanje relativnih zapremina vakuola, lizozoma, periksizoma, autofagozoma i lipida. Postojale su značajne razlike (p<0.05) između BCS1, BCS2, BCS4 i BCS5 krava i to u pojavi lipida, vakuola, lizozoma i autofagozoma u lutealim ćelijama u poređenju sa BCS3 kravama. Krave sa skorovima BCS2 ili BCS1, imale su povećane relativne zapremine masnih kapljica, dok su BCS4 i BCS5 krave imale povećanu pojavu (relativna zapremine) vakuola, lizozoma, peroksizoma i autolizozoma. Ovi rezultati ukazuju da luteoliza ciklinčnih CL ima različite karakteristike kod grupa krava sa različitim telesnim kondicijama; kod kahektičnih i utovljenih krava, proces luteolize započinje ranije u poređenju sa kravama koje su prosečnih telesnih kondicija.
Abstract
The aim of the study was to define ultrastructural changes in the ovarian cyclic corpus luteum (CL) of dairy cows with different body condition score (BCS, a 5-point scale). The ovaries were recovered from slaughtered Holstein cows of BCS1 (emaciation; n= 4), BCS2 (tendency to emaciation; n=4), BCS3 (average body condition; n= 4), BCS4 (tendency to fattening; n=4) and BCS5 (fattening; n=4). Average ages of cows were: 6.2, 4.1, 5.7, 5.5 and 6.36 years for BCS1, BCS2, BCS3, BCS4 and BCS5, respectively. For electron microscopy, functioning CL at the mid-luteal phase were fixed in the aldehyde solution and post-fixed in 1% OsO4 solution. For lipid visualization the samples were soaked in 1% p-phenylenediamine solution in acetone. Durcupan ultrathin sections (90 nm) were contrasted with uranyl acetate and lead citrate and viewed under Jeol transmission electron microscope. Occurrence of cell organelles was determined by counting the relative volume of individual cellular components using the modified universal test network. Luteal regression of cyclic CL was characterized by atrophy of lutein cells, condensation of organelles and cytoplasmic inclusions, increase in relative volumes of vacuoles, lysosomes, peroxisomes, autophagosomes and lipids. There were significant differences (p<0.05) among BCS1, BCS2, BCS4 and BCS5 cows in the occurrence of lipids, vacuoles, lysosomes and autophagosomes in the lutein cells compared to BCS3 cows. Cows with BCS2 or BCS1 had higher relative volume of lipid droplets, whilst the BCS4 or BCS5 cows had increased occurrence (relative volume) of vacuoles, lysosomes, peroxisomes and autolysosomes. These results show that luteolysis of cyclic CL of cows has different patterns in each BCS group; in the emaciated and fattened cows luteolysis starts earlier than in cows with average body condition.
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