Chronic stress and its effects on adrenal cortex apoptosis in pregnant rats

Abstract

The model of chronic intermittent stress by immobilization during pregnancy may produce alterations in the mechanisms that maintain adrenal gland homeostasis. In earlier investigations using this model, significant variations in plasma prolactin and corticosterone levels, and adrenal gland weights were observed. We hypothesized that chronic stress causes changes in apoptosis in the adrenal glands of pregnant rats. We identified and quantified apoptotic cells in the adrenal cortex and examined their ultrastructural characteristics using transmission electron microscopy. Adrenal glands of pregnant rats at gestation days 12, 17 and 21 were studied for control and experimental (stressed) rats. Immunolabelling techniques, stereological analysis and image quantification of adrenal gland sections were combined to determine differences in apoptosis in the different cell populations of the adrenal cortex. The apoptotic index of the experimental rats showed a significant reduction at gestation day 17, while at days 12 and 21 there were no differences from controls. Moreover, the apoptotic index of the reticular zones in control and experimental animals showed a significant increase compared to the glomerular and fascicular zones at the three gestation times studied. Chronic stress by immobilization reduced the caspase-dependent apoptotic index at gestation day 17, which may be related to variations in plasma concentrations of estrogens and prolactin.

New insights into morphological, stereological and functional studies of the adrenal gland under exposure to the potent goitrogen thiourea

“…In this section 50 test areas of the outer zona fasciculata (ZF) were counted (Sarwar et al ., 2008). Since the adrenocortical cells of rats are mononucleated, the numerical density of the nuclei corresponds to the number of cell per mm3 (Bozzo et al ., 2006). The test area was measured with a 10X objective using the Image-Pro Plus software (Rockville, USA).…”

Concentrate diet modulation of ruminal genes involved in cell proliferation and apoptosis is related to combined effects of short-chain fatty acid and pH in rumen of goats

“…The cells were then observed and photographed by a Laser Scanning Confocal Microscope (Zeiss LSM700, Carl Zeiss, Jena, Germany) at 460 and 620 nm. The apoptotic index was obtained from the ratio between apoptotic and normal nuclei multiplied by 100 (Bozzo et al, 2014).…”

<b>Alterações em adrenais de cães relacionadas à morte súbita ou agônica:</b> análise morfométrica, histopatológica, imunoistoquímica e correlação com os níveis de adrenalina e noradrenalina na medula adrenal

“…O peso e as dimensões das adrenais encontrados neste estudo são compatíveis com as médias descritas na literatura para a espécie canina (BAKER, 1937;GROOTERS;BILLER;MERRYMAN, 1995 DUTTA, 2015). Por outro lado, algumas condições patológicas, como doenças inflamatórias, hipotensão e hipóxia, podem levar à estimulação de apoptose nas células do córtex adrenal (WILLENBERG et al, 1998;BOZZO et al, 2006;YU et al, 2012).…”

“…O estudo de proliferação e apoptose celulares em cortes histológicos pode ser realizado através da avaliação de marcadores imunoistoquímicos, como PCNA e BAX e Bcl-2, respectivamente (FOGT et al, 1998;HOETELMANS et al, 2000;MADEWELL, 2001;BERNINI et al, 2002;BOZZO et al, 2006). O antígeno nuclear de proliferação celular (PCNA) está envolvido na síntese e no reparo de DNA durante a proliferação celular, sendo detectado desde a fase G1 até a transição G2 a M, atingindo seu pico na fase S do ciclo celular (MADEWELL, 2001).…”