Placental Iodothyronine Deiodinases Expression in Pregnant Cows Exposed to Propylthiouracil (Ptu) and Thyroid Axis Activity of their Calves

Abstract

The aim of our study was to investigate if the thyroid axis of newborn calves is affected by prenatal application of propylthyouracil (PTU). The study included 20 late pregnant Holstein cows. One group (n=10) was treated with PTU (4 mg/kg of BW daily) from day 20 before expected calving until the day of calving. The other group (n=10) was non-treated. Placental samples of dams were obtained for measuring mRNA expression of iodothyronine deiodinases type I (D1), type II (D2) and type III (D3). After parturition calves were separated from the dams and included in the study. Blood samples were taken daily from each calf starting on the day of birth until day 7 of age. Blood T 3, T 4 and TSH concentrations were measured. PCR analysis of the placental tissue revealed an abundance of all three types of placental deiodinases in non-treated cows, and a signifi cant elevation of mRNA levels for all three types of deiodinases after PTU treatment. Calves that originated from dams treated with PTU had signifi cantly lower T 3 and T 4 and signifi cantly higher TSH concentrations compared to non-treated calves during the fi rst 2 days of life. Starting from day 4 until day 6 of life the opposite effect was observed meaning that calves prenatally exposed to PTU had signifi cantly higher T 3 and T 4 and slightly lower TSH. Our study, for the fi rst time, provides information related to iodothyronine deiodinases mRNA expression in bovine placenta, and confi rm that PTU treatment of pregnant dams provokes depression of thyroid function in newborns during the fi rst days of life.

Age-related functional changes of total thyroid hormones and glycosaminoglycans in growing calves

“…The hypothalamic-pituitary-thyroid (HPT) axis plays a consistent role in the growth and development of fetal and neonatal calves [1,2], according to metabolic and non-metabolic mechanisms [3][4][5]. Indeed, thyroid hormones play a crucial role in successful implantation and during the early stages of embryo development [6,7], suggesting a local action of thyroid hormones and thyroid-stimulating hormone (TSH) on both the endometrium and the embryo [8,9].…”

“…Fetal thyroid function is under a strong maternal thyroid axis's influence, on the basis of placental permeability for iodine, improving fetal thyroid hormone synthesis [13,14]. Nevertheless, there is no evidence about thyroid hormones transfer through the ruminants' placenta [2]. During the physiological development, thyroid changes dynamically occur, according to genetic and non-genetic factors, nutritional intake [15], environmental stimuli [16], and deiodinases' expression [2].…”

“…Nevertheless, there is no evidence about thyroid hormones transfer through the ruminants' placenta [2]. During the physiological development, thyroid changes dynamically occur, according to genetic and non-genetic factors, nutritional intake [15], environmental stimuli [16], and deiodinases' expression [2]. High fetal thyroid hormones' concentration after birth in 1 day old neonatal calves were observed, and a significant decrease along the next several days was also recorded, providing sufficient amounts of thyroid hormones for early postnatal development [17].…”

Z-cells and oogonia/oocytes in the advanced process of autophagy are the dominant altered cells in the ovaries of hypothyroid newborn rats

“…Effects of maternal hypothyroidism on offspring health are important in human [1] and veterinary medicine [2]. Previously, in the rat model, we have shown that maternal hypothyroidism during pregnancy and lactation leads to premature ovarian failure of pubertal and adult offspring [3].…”

Transcriptomic Changes in Response to Form of Selenium on the Interferon-Tau Signaling Mechanism in the Caruncular Tissue of Beef Heifers at Maternal Recognition of Pregnancy

“…This selenoprotein converts T4 to T3 by deiodination of the outer ring, and it can convert T3 and T4 into the inactive T2 or rT3, respectively, via inner ring deiodination [46]. Given the primary localization and function of DIO1, it is not unsurprising that we were unable to detect a measurable concentration of mRNA encoding this protein in CAR samples; however, it should be noted that previous studies have shown DIO1 to be abundant in the term placenta [47], which may be associated with circulating concentrations of T3 being highest at parturition [47,48].…”