Haematological and serum biochemical values in spontaneously epileptic male rats and related rat strains

Acute toxicity analysis of an inhibitor of BCL2, Disarib, in rats

Apoptosis or programmed cell death is a highly regulated process, which eliminates unwanted and damaged cells. Inhibition of apoptosis is a hallmark of cancer cells. BCL2 family proteins are known to play a vital role in the regulation of apoptosis. Overexpression of BCL2, an antiapoptotic protein, provides the advantage of prolonged survival to cancer cells. Over the years, several BCL2 inhibitors have been investigated extensively for their anticancer potential. However, most of them were abolished before clinical use due to their side effects. Previously, we had identified and characterized a novel BCL2 inhibitor, Disarib, with the potential to eliminate tumor cells in a BCL2 specific manner leading to reduction in tumor burden in multiple mouse models. Notably, a head-to-head comparison of Disarib to ABT199, the only FDA approved BCL2 inhibitor revealed that Disarib is as potent as ABT199. Recent studies using mice revealed that Disarib did not invoke significant side effects in mice. In the present study, we have investigated the acute toxicity of Disarib in Wistar rats. The bioavailability studies following exposure of Disarib in Wistar rats revealed its maximum availability in serum at 24 h following oral administration. Acute toxicity analysis revealed that even a dose as high as 2000 mg/kg of Disarib did not cause significant toxicity in rats. There was no significant variation in blood parameters or kidney and liver functions following administration of Disarib. Histological analysis of different tissues from Disarib treated groups revealed standard architecture with no observable cellular damage. Importantly, exposure to Diasrib did not result in genotoxicity as determined by micronucleus assay. Further, solubility assays revealed that besides DMSO, Disarib is also soluble in alcohol. While the high acidic condition can increase the solubility of Disarib, even a lower percentage of alcohol with acidic conditions can improve its solubility. Thus, the toxicological profile in the current study revealed no significant side effects when Disarib was administered orally to rats.

Iron accumulation in the choroid plexus, ependymal cells and CNS parenchyma in a rat strain with low-grade haemolysis of fragile macrocytic red blood cells

Iron accumulation in the CNS is associated with many neurological diseases via amplification of inflammation and neurodegeneration. However, experimental studies on iron overload are challenging, since rodents hardly accumulate brain iron in contrast to humans. Here, we studied LEWzizi rats, which present with elevated CNS iron loads, aiming to characterise choroid plexus, ependymal, CSF and CNS parenchymal iron loads in conjunction with altered blood iron parameters and, thus, signifying non‐classical entry sites for iron into the CNS. Non‐haem iron in formalin‐fixed paraffin‐embedded tissue was detected via DAB‐enhanced Turnbull Blue stainings. CSF iron levels were determined via atomic absorption spectroscopy. Ferroportin and aquaporin‐1 expression was visualised using immunohistochemistry. The analysis of red blood cell indices and serum/plasma parameters was based on automated measurements; the fragility of red blood cells was manually determined by the osmotic challenge. Compared with wild‐type animals, LEWzizi rats showed strongly increased iron accumulation in choroid plexus epithelial cells as well as in ependymal cells of the ventricle lining. Concurrently, red blood cell macrocytosis, low‐grade haemolysis and significant haemoglobin liberation from red blood cells were apparent in the peripheral blood of LEWzizi rats. Interestingly, elevated iron accumulation was also evident in kidney proximal tubules, which share similarities with the blood–CSF barrier. Our data underscore the importance of iron gateways into the CNS other than the classical route across microvessels in the CNS parenchyma. Our findings of pronounced choroid plexus iron overload in conjunction with peripheral iron overload and increased RBC fragility in LEWzizi rats may be seminal for future studies of human diseases, in which similar constellations are found.

Evaluation of Maternal Reproductive Outcomes and Biochemical Analysis from Wistar Audiogenic Rats (WAR) and Repercussions in Their Offspring

The objective of the present study was to evaluate maternal reproductive performance, body weight, and frequency of external and internal anomalies of newborns of Wistar Audiogenic Rat (WAR) females as compared with Wistar rats. The adult WAR and Wistar rats were mated within their respective strains. After confirming the pregnancy, the body weights were weekly evaluated. On day 21 of pregnancy, the female rats were anesthetized and sacrificed to evaluate the maternal reproductive outcomes and biochemical profile, newborn weight, and external and internal anomalies. The WAR strain gained less weight during the pregnancy and presented hyperproteinemia, hypertriglyceridemia, and embryonic losses concerning Wistar rats, suggesting an inadequate intrauterine condition for embryonic development and fetal viability. WAR also presented a higher percentage of newborns classified as small for gestational age related to intrauterine growth restriction, which was confirmed by the lower number of ossification centers. There was a higher percentage of skeletal anomalies compared with fetuses of the Wistar dams, confirming their greater susceptibility during the formation and development of their skeletal system. Thus, the WAR presents physiological alterations compromising the viability of their embryos and fetuses, leading to impaired development of the newborns.

Antihypertensive and antioxidant effects of protocatechuic acid in deoxycorticosterone acetate-salt hypertensive rats

Protocatechuic acid (PCA) is a natural antioxidant with beneficial cardiovascular properties. In this study, the effect of supplementation with PCA was investigated in deoxycorticosterone acetate (DOCA)-salt hypertension. Male Wistar rats received DOCA (25 mg/kg, s.c.) twice weekly and 1% NaCl in drinking water and simultaneously treated with PCA (50, 100 and 200 mg/kg, p.o.) for 4 weeks. Systolic blood pressure (SBP) was detected using tail-cuff method. Electrolytes including Na⁺, K⁺ and chloride, catalase activity, glutathione, total antioxidant capacity, malondialdehyde (MDA) and hydroperoxides concentration were measured in serum samples. Body and organs weight, water intake and, kidney and heart histopathology were also evaluated. Administration of PCA reversed the changes caused by DOCA-salt approximately at all doses. At the lowest dose, PCA significantly decreased SBP (132.5 ± 4.0 vs 152.3 ± 4.5 mmHg, P < .05), serum sodium (138.5  ± 1.52 vs 141 ± 1.50, P < .05) and chloride level (101.6 ± 1.47 vs 110 ± 1.39, P < .01) and raised serum potassium level (3.8 ± 0.09 vs 3.1 ± 0.17, P < .05) compared with DOCA-salt hypertensive rats. PCA increased serum catalase activity, total antioxidant capacity and glutathione concentration and reduced MDA and hydroperoxides levels. PCA also improved organ weight changes, reduced water intake and moderately prevented histopathological changes of kidney and heart upon DOCA-salt administration. The present study indicates the antihypertensive and antioxidant effects of PCA against DOCA-salt hypertension.

A novel mutation vf causing abnormal vacuoles in the central nervous system maps on rat chromosome 8

Body-tremorous rats were found in a colony of WTC-tm rats and a new coisogenic mutant strain void of the tm mutation was established. Histological analysis revealed that these rat mutants had abnormal vacuoles in the red nucleus of the midbrain, the reticular formation in the brain stem, and the white matter of the cerebellum and spinal cord. Electron microscopic observation showed many irregular myelin-bound vacuoles and degenerated oligodendroglia. Genetic analysis indicated that the presence of the abnormal vacuoles in the central nervous system (CNS) is controlled by a recessive gene named "vacuole formation (vf)" on chromosome (Chr) 8, and that this gene is also involved in the appearance of body tremors. Comparative maps suggested that the mouse and human orthologs would be located on Chr 9 (43-48 cM) and Chr 6 (328-370 cR3000), respectively. Since similar mutations have not been mapped yet around these regions, the authors believe this novel rat mutation will allow the discovery of a new function of these particular genes that is involved in the development and maintenance of the CNS.