Alterations in hypothalamic synaptophysin and death markers may be associated with vasopressin impairment in sepsis survivor rats

Abstract

The impairment in arginine vasopressin (AVP) secretion during sepsis is described in clinical and experimental studies and has been associated with oxidative stress, apoptosis, and diminished activation of hypothalamic neurons. Few studies have, however, assessed these abnormalities in sepsis survivors. Here we performed two sets of experiments on Wistar rats that had been subjected to sepsis by cecal ligation and puncture (CLP) or nonmanipulated (naive) as control. In the first set, tissues and blood were collected from survivor rats 10 days after CLP to quantify hypothalamic Bcl-2, cleaved caspase- 3 and synaptophysin content, and bacterial load. In the second set, survivor rats were submitted to an acute osmotic stimulus (hypertonic saline), and after 30 minutes the water intake and AVP secretion were analyzed. The sepsis-surviving rats did not show bacterial load in tissues, but their hypothalamic synaptophysin and Bcl-2 levels were decreased, and the cleaved caspase- 3 level was increased when compared with the control group. However, AVP secretion was significantly attenuated in the CLP survivor animals submitted to an acute osmotic stimulus. These results suggest that the persistent AVP impairment in sepsis survivor animals may be due to a hypothalamic dysfunction associated with a synaptic deficit and decreased anti-apoptotic protein expression. This article is protected by copyright. All rights reserved.

Role of AMPA and NMDA receptors on vasopressin and oxytocin secretion induced by hypertonic extracellular volume expansion

“…cannula. The inflammation process has been shown to impair both AVP and OT secretion . On the other hand, in the present study, the hypertonic EVE was able to increase both AVP and OT plasma levels as expected.…”

Environmental Enrichment Protects Against Sepsis-Associated Encephalopathy-Induced Learning and Memory Deficits by Enhancing the Synthesis and Release of Vasopressin in the Supraoptic Nucleus

“…A previous study revealed that 10 days after sepsis induction, no sepsis signals could be observed in the plasma and the contents of inflammatory mediators in the plasma were similar to those of the control group. 80 Our results further confirmed these findings by showing that the serum contents of inflammatory mediators showed no differences among the three groups.…”

Inflammatory, synaptic, motor, and behavioral alterations induced by gestational sepsis on the offspring at different stages of life

“…Recently, a decrease in synaptophysin and PSD95 expression was described following neuroinflammation induced by the cecal ligation and puncture (CLP) model of sepsis [ 77 , 78 ] or after intraperitoneally administration of LPS—a component of Gram-negative bacteria [ 79 – 82 ]. There are few studies that correlate infection during gestation and disturbance of synaptophysin expression in the offspring and none using bacterial sepsis models.…”