Effects of hyperthyroidism on expression of vascular endothelial growth factor (VEGF) and apoptosis in fetal adrenal glands

Abstract

This study investigated the expression of vascular endothelial growth factor (VEGF), vascular density, and apoptosis in fetal rat adrenal glands with hyperthyroidism in late gestation. Twelve mature female Wistar albino rats with the same biological and physiological features were used for this study. Rats were divided into two groups: control and hyperthyroidism. Hyperthyroidism was induced by daily subcutaneous injections of L-thyroxine (250 µg/kg) before pregnancy for 21 days and during pregnancy. Rats in the control and hyperthyroidism groups were caged according to the number of male rats. Zero day of pregnancy (Day 0) was indicated when the animals were observed to have microscopic sperm in vaginal smears. Pregnant rats were sacrificed on the 20th day of pregnancy; blood from each animal was collected to determine the concentrations of maternal adrenocorticotropic hormone and thyroxine. Rat fetuses were then quickly removed from the uterus, and the adrenal glands of the fetuses were dissected. VEGF expression, vascular density, and apoptosis were analyzed in fetal rat adrenal glands. Maternal serum levels of the ACTH and free thyroxine were significantly higher in the hyperthyroidism group than in the control group. Immunohistochemistry revealed that the number of VEGF positive cells and vessel density significantly increased in the hyperthyroidism rat fetal adrenal group compared with the control group. Hyperthyroidism did not change the fetal and placental weights and the number of fetuses. This study demonstrates that hyperthyroidism may have an effect on the development of rat adrenal glands mediated by VEGF expression, angiogenesis, and apoptosis.

Excesso de tiroxina materna associado ao hipertireoidismo pós-natal reduz o crescimento ósseo e o perfil proliferativo e angiogênico das cartilagens de crescimento de ratos

“…No entanto, as consequências dessa disfunção sobre o tecido ósseo são variáveis e dependentes de fatores, como dose de tiroxina administrada, perfil sérico dos hormônios sexuais, curso da doença (Serakides et al, 2004), sítio ósseo (Suwanwalaikorn et al, 1996;Milne et al, 1998) e idade (Nicholls et al, 2012). Assim, no hipertireoidismo, a massa óssea pode estar aumentada, normal ou reduzida (Mundy et al, 1976;Allain et al, 1995;Karga et al, 2004;Serakides et al, 2004;Desjardin et al, 2014). Similar aos achados deste estudo, Allain et al (1995) (Karaca et al, 2015), e em tecidos como corpo lúteo (Silva et al, 2013) e placenta (Silva et al, 2015).…”

“…Assim, no hipertireoidismo, a massa óssea pode estar aumentada, normal ou reduzida (Mundy et al, 1976;Allain et al, 1995;Karga et al, 2004;Serakides et al, 2004;Desjardin et al, 2014). Similar aos achados deste estudo, Allain et al (1995) (Karaca et al, 2015), e em tecidos como corpo lúteo (Silva et al, 2013) e placenta (Silva et al, 2015). Durante o crescimento ósseo endocondral, a angiogênese mediada pelo VEGF é importante para a formação e a reabsorção da cartilagem, assim como para a mineralização (Carlevaro et al, 2000;Maes et al, 2002).…”

“…Durante a vida embrionária e fetal e durante o crescimento pós-natal, a angiogênese ocorre concomitantemente ao processo de proliferação celular. A vasculatura fornece oxigênio, nutrientes e fatores de crescimento às células e aos tecidos (Karaca et al, 2015). Para que isso ocorra, a matriz extracelular das cartilagens de crescimento desempenha função importante na difusão de substâncias, particularmente das moléculas de sinalização e dos fatores de crescimento (Cortes et al, 2009).…”

Histochemistry today: Detection and location of single molecules

“…Several papers were aimed at illustrating the tissue organization and protein expression of still poorly described organs from various Vertebrate and Invertebrate species: [42][43][44][45][46][47][48][49][50][51][52][53][54] here, the morphological description of the microanatomical and histological features was paralleled by the detection of specific molecules responsible for the tissue functional characteristics, also as a consequence of seasonal dynamic changes. [55][56][57] The immunolabeling of marker proteins was extensively applied in studies aimed at distinguishing stem/progenitor cells or at elucidating the process of cell differentiation and morphogenesis during pre-and post-natal development in mammals, including humans, [58][59][60][61][62][63][64][65][66][67][68][69][70][71][72][73][74][75][76] with special attention to the nervous system, 65,66 sensory organs, [67][68][69] skin, 70 lung, 70,71 and the skeletal apparatus. [72][73][74][75] Also in plants, the histochemical d...…”

Is there still room for novelty, in histochemical papers?

“…In the papers on Stem cells & Development 55-72 the expression of specific proteins was investigated during fetal development, 55 with particular reference to skin, 56 lung, 57,58 kidney, 59 pituitary and adrenal gland, 60,61 developing cartilage and bone, 62-65 and cochlea. 66,67 The presence of progenitor stem cells has been detected in the kidney, 68 cerebral cortex 69 and cerebellum 70 during human embryogenesis.…”