Vacuolar Pathology in the Median Eminence of the Hypothalamus After Hyponatremia

Abstract

The median eminence of the hypothalamus is an important conduit by which neurosecretory hormones from hypothalamic nuclei are delivered to the pars nervosa (neural lobe) of the pituitary en route to the bloodstream. Dilutional hyponatremia was produced in adult rats to determine the effect on the morphology of the median eminence of the hypothalamus. Hyponatremia was caused by reducing electrolyte and organic osmolyte reserves in order to block the excretion of water through delivery of the nephrotoxin mercuric chloride (HgCl2). Histological examination of the brain 1 day following a hyponatremic insult revealed vacuolation within the median eminence of the hypothalamus. No other lesions were found in other parts of the brain following hyponatremia. The hyponatremic lesion consisted of a band of closely packed vacuoles that crossed the floor of the third ventricle. Vacuoles associated with hyponatremia were predominantly in the subependymal, fiber, reticular, and palisade layers of the median eminence. Vacuolation was not observed in the tanycyte layer of the median eminence. This study indicates that the median eminence is a potentially vulnerable site in human hyponatremic conditions that should be evaluated further in relevant animal models.

The effect of chronic stress on the testis of adult albino Rats and the possible protective effect of astaxanthin supplementation (Histological, immunohistochemical and biochemical studies)

“…Electron microscopic results showed Sertoli cell with an irregular nuclear envelope, many cytoplasmic vacuoles and dilated SER.These findings were in accordance withAgarwal et al [33] who reported that oxidative stress led to appearance of cytoplasmic vacuolations in Sertoli cells. Also, Levine et al [36] attributed the appearance of cytoplasmic vacuolations to the hydropic degeneration resulting from mitochondrial dysfunction and disruption of sodium pump with increased sodium influx and attraction of water. Also, multiple electron dense bodies with variable sizes and lysosomes were noticed in cytoplasm of Sertolicell in the stress group.…”

Role of bone marrow derived mesenchymal stem cells in protection of spermatogenic and Sertoli cells against histological alterations induced by torsion/detorsion in rats

“…Also, that could be explained according to Siu and his colleagues who reported that oxidative stress due to I/R led to appearance of cytoplasmic vacuolations in Sertoli cells with disruption of blood testis barrier [22] . Levine and his colleagues attributed the appearance of cytoplasmic vacuolations to the hydropic degeneration resulting from mitochondrial dysfunction and disruption of sodium pump with increased sodium influx and attraction of water [23] .…”