Histological and ultrastructural alterations of rat interscapular brown adipose tissue in experimentally induced systemic hyperthyroidism
Histološke i ultrastrukturne promene interskapularnog mrkog masnog tkiva pacova u eksperimentalno indukovanom sistemskom hipertiroidizmu
Докторанд
Rajab, Njia Milad A.Ментор
Čakić-Milošević, MajaЧланови комисије
Glišić, RadmilaUkropina, Mirela
Čakić-Milošević, Maja
Метаподаци
Приказ свих података о дисертацијиСажетак
Overweight and obesity, caused by imbalance between energy intake and energy
expenditure, are growing public health problem worldwide. Brown adipose tissue
(BAT), as energy dissipating tissue, emerged as possible target for antiobesity therapy.
Thyroid hormones play an important role in regulation of temperature
homeostasis and energy metabolism and they are involved in regulation of BAT
activity. Thus, continuous crosstalk between thyroid gland/hormones and adipose
tissue may be important for body weight control. While the importance of thyroid
hormones for proper BAT function is well known, the influence of systemic
hyperthyroidism on BAT activity is not yet fully understood.
This dissertation started from two directly confronted premises concerning the
place of BAT in thyroid thermogenesis. The first of them implies that BAT thermogenic
function in systemic hyperthyroidism is suppressed while according to the other one
BAT is effectory organ of thyroid thermogenesis. Therefore, this... dissertation aims to
investigate the effects of experimentally induced systemic hyperthyroidism on structural
remodelling and thermogenic capacity of BAT in order to shed more light on regulatory
mechanisms controlling its function. Also, the aim was to analyse differences, if any,
between effects of two thyroid hormones, T3 and T4.
The experiment was performed on a total of 18 male Wistar rats, kept under
standard laboratory conditions, at the room temperature. Animals from the first
experimental group received T3 in dose of 200 =g/kg b.w., . while animals from the
second experimental group received T4 in dose of 300 =g/kg b.w., ., once a day,
during five days. Rats from the third group were treated with vehicle only, according to
the same schedule.
Histological and histochemical analyses of BAT were performed at the level of
light microscopy using 5 =m thick paraffin sections of routinely processed tissue stained
with hematoxylineosine, PAS, Bodian and Novelli methods. For detection of apoptosis,
propidium iodide method was used...
Povećana telesna težina i gojaznost prouzrokovane disbalansom izmeñu unosa
energije i njenog trošenja, predstavljaju rastući zdravstveni problem u svetu. Mrko
masno tkivo (MMT), kao tkivo koje rasipa energiju, postaje moguće ciljno tkivo za
lečenje gojaznosti.
Tiroidni hormoni imaju važnu ulogu u regulaciji temperaturne homeostaze i
energetskog metabolizma i uključeni su u regulaciju aktivnosti MMT. Prema tome,
postojanje stalne komunikacije izmeñu tiroidne žlezde/tiroidnih hormona i masnog tkiva
može biti značajno za kontrolisanje telesne težine. I dok je značaj tiroidnih hormona za
ispravno funkcionisanje MMT dobro poznato, uticaj sistemskog hipertiroidizma na
njegovu aktivnost još uvek nije u potpunosti shvaćen.
Ova disertacija bazirana je na dve meñusobno suprotstavljene polazne
pretpostavke koje se tiču mesta MMT u tiroidnoj termogenezi. Prva podrazumeva
supresiju termogene funkcije MMT u sistemskom hipertiroidizmu, dok prema drugoj
MMT predstavlja efektorski organ tiroidne termog...eneze. Prema tome, cilj ove
disertacije bio je ispitivanje efekata eksperimentalno indukovanog sistemskog
hipertireoidizma na strukturno remodeliranje i termogeni kapacitet MMT, kako bi se
doprinelo razjašnjavanju mehanizama njegove regulacije. Isto tako, cilj je bio analizirati
razlike, ako ih ima, u efektima dva glavna tiroidna hormona, T3 i T4.
Eksperiment je izveden na ukupno 18 mužjaka Wistar pacova, držanih pod
standardnim laboratorijskim uslovima, na sobnoj temperaturi. Životinje iz prve
eksperimentalne grupe primale su T3 u dozi od 200 =g/kg b.w., . dok su životinje iz
druge eksperimentalne grupe primale T4 u dozi 300 =g/kg b.w., ., jednom dnevno,
tokom pet dana. Pacovi iz treće grupe bili su tretirani samo prenosnikom, prema istom
rasporedu.
Histološka i histohemijska analiza MMT obavljena je na nivou svetlosne
mikroskopije, korišćenjem 5 =m parafinskih preseka rutinski sprovedenog tkiva,
obojenih hematoksilinomeozinom, PAS metodom, Bodian metodom i Novelli
metodom...