Hormonalni i metabolički status teladi neonatalnog peioda poreklom od primaparnih majki tretiranih sa propiltiouracilom tokom graviditeta

Abstract

Cilj ove doktorske je bio da se ispita efekat hipotireoze majke indukovane tokom kasnog graviditeta na endokrini i metabolički status novorođenih teladi tokom prvih sedam dana neonatalnog života. Hipotireoza majke je indukovana davanjem PTU u dozi od 4mg/kg telesne mase tokom poslednjih 20 dana graviditeta. Nakon rađanje, telad koja potiču od majki tretiranih sa PTU (n=10) je svrstano u oglednu grupu, dok je 10 teadi koja su poticala od majki koje nisu tretirane sa PTU svrstano u kontroln grupu. Sva telad su bila odmah po rođenju odvojena od majki i napajana kolostrumu i mlekom tokom ispitivanog perioda. Svakodnevno, tokom prvih sedam dana neonatalnog života teladima je uzimana krv punkcijom v. jugularis. Odmah nakon rođenja teladi uzimani su uzorci tkiva placente majke i tkiva tireoidee teladi. Koncentracija tireoidnih hormona i koncentracija TSH ispitivana je u svim uzetim uzorcima krvi. U uzorcima krvi uzetih 0., 1., 2., 3., 4. i 7. dana nakon rođenja određene su koncentracije glukoze, insulina, kortizola, IGF-I i relativna zastupljenost IGFBP-2 i IGFBP-3. U svim uzorcima krvi uzetih tokom sedam dana ispitivanja, ispitane su koncentracije ukupnih proteina, albumina i globulina, kao i koncentracije holesterola i triglicerida. U uzorcima tkiva placente majki i tkiva tireoidee teladi, ispitivana je ekspresija iRNK za pojedine tipove dejodinaze, dok su u uzorcima tkiva tireoidee određivane i histološke promene. Telad ogledne grupe rađala su se sa značajno nižim koncentracijama tireoidnih hormona (T3 i T4) i značajno višim koncentracijama TSH u odnosu na telad kontrolne grupe. Ova razlika je bila značajna tokom prva dva dana neonatalnog života. Počevši od 3. dana, koncentracije tireoidnih hormona su se kod ogledne grupe povećavale, a TSH snižavale, tako da su koncentracije tireoidnih hormona u periodu od 4. do 6. dana bile značajno više a koncentracije TSH značajno niže kod ogledne nego kod kontrolne grupe. Koncentracije insulina su u momentu rođenja bile značajno niže kod teladi ogledne grupe u odnosu na telad kontrolne grupe. Vrednosti insulinemije su se kod ogledne grupe povećavale tako da je vrednost bila veća nego kod kontrolne grupe već 4. dana, iako ne statistički značajno...

The aim of this PhD thesis was to was to examine the effect of induced hypothyroidism in Holstein heifers in the latest stage of pregnancy on endocrine end metabolic status of newborn calves during the first seven days of neonatal life. The study was conducted by inducing hypothyroid state in the dams by oral treatment with 4mg PTU/kg body weight, during a period of 20 days prior to expected calving. After birth, calves originating from dams treated with PTU (n = 10) were classified as experimental group, while 10 calves that originated from dams not treated with PTU were classified as the control group. All calves were separated immediately after birth from their dams and fed colostrum and milk during the test period. During this period, calves body weight was also determined. Blood samples were taken daily by puncture of v. jugularis from each calf for the first seven days of life. Immediately after parturition placental samples and calves thyroid tissue samples were obtained. Concentrations of thyroid hormones and TSH were determined in all blood samples. Concentration of IGF-I and relative presence of IGFBP-2 and IGFBP-3 were determined in samples taken on days 1, 2, 3, 4 and 7 after birth. Concentrations of glucose, insulin and cortisol were determined in samples taken on days 1, 2, 3, 4, 7. Concentrations of total protein, albumin, globulin, triglyceride and cholesterol were determined in samples obtained during the all seven days of study period. On placental and thyroid tissue samples, expression of iRNA for DIO1, DIO2 and DIO3 were determined. Determination of histological changes was done on thyroid tissue samples taken from calves with established macroscopic changes on thyroid gland. Calves in experimental group were born with significantly lower thyroid hormone concentrations and significantly higher TSH concentrations compared to control group. Hypothyroid state was significant within the first two days after birth. After day 3, concentrations of thyroid hormones increased, so in the period of days 4, 5 and 6 they were higher compared to the control group, while the TSH concentrations decreased until day 4 after which the TSH concentrations were lower compared to the control group...