Inner capillary diameter of hypothalamic paraventricular nucleus of female rat increases during lactation.

BACKGROUND: The role of the endothelial cell (EC) in blood flow regulation within the central nervous system has been little studied. Here, we explored EC participation in morphological changes of the anterior hypothalamic paraventricular nucleus (PVN) microvasculature of female rats at two reproductive stages with different metabolic demand (virginity and lactation). We measured the inner capillary diameter (ICD) of 800 capillaries from either the magnocellular or parvocellular regions. The space occupied by neural (somas, dendrites and axons) and glial, but excluding vascular elements of the neurovascular compartment was also measured in 100-µm2 sample fields of both PVN subdivisions. RESULTS: The PVN of both groups of animals showed ICDs that ranged from 3 to 10 microns. The virgin group presented mostly capillaries with small ICD, whereas the lactating females exhibited a significant increment in the percentage of capillaries with larger ICD. The space occupied by the neural and glial elements of the neurovascular compartment did not show changes with lactation. CONCLUSIONS: Our findings suggest that during lactation the microvasculature of the PVN of female rats undergoes dynamic, transitory changes in blood flow as represented by an increment in the ICD through a self-cytoplasmic volume modification reflected by EC changes. A model of this process is proposed.

Corrigendum: Cognitive Impairment After Resolution of Hepatic Encephalopathy: A Systematic Review and Meta-Analysis.

[This corrects the article DOI: 10.3389/fnins.2021.579263.].

Cognitive Impairment After Resolution of Hepatic Encephalopathy: A Systematic Review and Meta-Analysis.

Hepatic encephalopathy (HE) is one of the most disabling metabolic diseases. It consists of a complication of liver disease through the action of neurotoxins, such as excessive production of ammonia from liver, resulting in impaired brain function. Its prevalence and incidence are not well known, although it has been established that up to 40% of cirrhotic patients may develop HE. Patients with HE episodes display a wide range of neurological disturbances, from subclinical alterations to coma. Recent evidence suggests that the resolution of hepatic encephalopathy does not fully restore cognitive functioning in cirrhotic patients. Therefore, the aim of this review was to evaluate the evidence supporting the presence of lingering cognitive deficits in patients with a history of HE compared to patients without HE history and how liver transplant affects such outcome in these patients. We performed two distinct meta-analysis of continuous outcomes. In both cases the results were pooled using random-effects models. Our results indicate that cirrhotic patients with a history of HE show clear cognitive deficits compared control cirrhotic patients (Std. Mean Difference (in SDs) = -0.72 [CI 95%: -0.94, -0.50]) and that these differences are not fully restored after liver transplant (Std. Mean Difference (in SDs) = -0.72 [CI 95%: -0.94, -0.50]).

The effects of castration and hormone replacement on the cross-sectional area of pubococcygeus muscle fibers in the female rat.

In this study, we analyzed the effect of ovariectomy and gonadal hormone replacement on the cross-sectional area of pubococcygeus (Pcm) fibers. It was found that in comparison to intact animals, ovariectomized animals [for 2 or 6 weeks] had an increased cross-sectional area average in Pcm fibers. Ovariectomy also reduced the percentage of fibers with smaller cross-sectional area. In ovariectomized animals after 4 weeks of hormone replacement with an empty Silastic capsule or filled with testosterone propionate or dihydrotestosterone, significantly increased the cross-sectional area average and the percentage of fibers with larger size. However, 17ß-estradiol but not estradiol benzoate treatment reduced the cross-sectional area average and increased the percentage of Pcm fibers with smaller size. Progesterone did not have an effect on the cross-sectional area of this muscle. We conclude that Pcm fibers of female rats are sensitive to gonadal hormones, and contrary to male castration, ovariectomy promotes an increase in their cross-sectional area. Also, we discuss according to other studies that an external mechanism which lies within the neuromuscular periphery could also participate in the modulatory hormonal effect on mass or muscle fiber size. Furthermore, in this process, estradiol is likely to regulate the fiber cross-sectional area growing produced by androgens.