Quantitative morphological or histological features within the hepatic acinus were studied to determine the proportional difference of tissue components by regions or zones in different ages in the male albino rat of the Sprague-Dawley strain. In the newborn rat, weighing about 6 gm. there were lesser cytoplasmic and greater nuclear volumes per unit volume of the hepatic cell than for these components of the hepatic cells of the adult rat weighing about 160 gm. No difference between the volume occupied by the hepatic sinusoid per unit volume of the hepatic acinus was found. In the newborn rat the ratio of hits on cytoplasm of the hepatic cell to hits on nuclei of the hepatic cell throughout the zones of the hepatic acinus was fairly uniform. However, the hepatic sinusoid of Zone 3 or the pericentral area was wider than that of the other zones. In the adult rat the ratio of hits on cytoplasm to hits on nuclei of the hepatic cell throughout the zones of the hepatic acinus was not significantly different. However, the hepatic sinusoid of Zone 3was wider than that of Zone 2 and the sinusoid of Zone 3 was not significantly different from that of Zone 1 in volume. Consequently it was concluded that the quantitative morphological or histological features of hepatic tissue components conformed to the points of regions or zones of the hepatic acinus in different ages in the normal albino rat.
Age Factors ; Animal ; Animals, Newborn/analysis ; Cell Nucleus ; Cytoplasm ; Human ; Infant, Newborn ; Liver/cytology* ; Male ; Models, Biological ; Rats

OBJECTIVETo study the expression of Toll-like receptor 4 (TLR-4) and caspase-3 in the intestine of neonatal rats with necrotizing enterocolitis (NEC), and explore the protective effects and possible regulatory mechanisms of glutamine (Gln) in NEC.

METHODSSixty premature rats were randomly divided into three groups (n=20 each): control, NEC model and Gln intervention group. NEC model was prepared by formula feeding, hypoxia and cold stress. The Gln intervention group was also subjected to hypoxia and cold stress but was fed with formula containing Gln (0.3 g/kg). Two days later, the rats were sacrificed and the intestine tissues were obtained. The histological changes of ileal tissues were observed by hemetoxylin and eosin staining. The expression of caspase-3 and TLR-4 protein in the jejunum, ileum and colon were detected by inmunohistochemistry. The expression of TLR-4 mRNA in the jejunum, ileum and colon were detected by RT-PCR.

RESULTSCompared with the control group, the histological score of ileal tissues, and the expression of caspase-3, TLR-4 protein and TLR-4 mRNA in the NEC model group increased significantly (P<0.01). Gln intervention decreased significantly the histological score of ileal tissues, and the expression of caspase-3, TLR-4 protein and TLR-4 mRNA compared with the NEC model group (P<0.05).

CONCLUSIONSTLR-4 might be involved in the pathogenesis of NEC. Gln may provide protective effects on intestine possibly through reducing the TLR-4 expression and then decreasing the apoptosis of intestinal epithelial cells.

Animals ; Animals, Newborn ; Caspase 3 ; analysis ; Enterocolitis, Necrotizing ; metabolism ; pathology ; Female ; Glutamine ; pharmacology ; Immunohistochemistry ; Pregnancy ; RNA, Messenger ; analysis ; Rats ; Rats, Sprague-Dawley ; Toll-Like Receptor 4 ; analysis ; genetics

OBJECTIVETo study the changes of ephrin-B3 mRNA expression and cellular apoptosis in the brain of neonatal rats with periventricular leukomalacia (PVL) and to explore the possible role of ephrin-B3 in the pathogenesis of PVL.

METHODSTwo-day-old SD rats were randomly assigned to two groups: PVL and control. PVL model was prepared by right common carotid artery ligation followed by 4-hr 6% oxygen exposure. The control group, without ligation of the artery and hypoxia treatment, was sham operated. The rats were then sacrificed and brain tissues were collected at 0, 8, 24, 48 and 72 hrs and at 7 days of hypoxic-ischemia (HI). Hematoxylin and eosin staining was used for pathologic studies. Real time RT-PCR was applied to detect brain ephrin-B3 mRNA expression. DAPI staining was applied to detect neuronal apoptosis.

RESULTSThe brain ephrin-B3 mRNA expression increased significantly in the PVL group at 8, 24, 48 and 72 hrs and at 7 days of HI compared with that of the control group (P < 0.05). The apoptotic cells in the brain of the PVL group were significantly more than that of the control group at 8, 24, 48 and 72 hrs of HI (P < 0.05).

CONCLUSIONSephrin-B3 mRNA expression and cellular apoptosis in the brain increased significantly in neonatal rats with PVL, which suggests that ephrin-B3 may participate in the pathogenesis of PVL in neonatal rats.

Animals ; Animals, Newborn ; Apoptosis ; Brain ; pathology ; Ephrin-B3 ; genetics ; Humans ; Infant, Newborn ; Leukomalacia, Periventricular ; metabolism ; pathology ; RNA, Messenger ; analysis ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo establish a neonatal pig model of hemolytic jaundice.

METHODSTwelve seven-day-old purebred Yorkshire pigs were randomly divided into an experimental group and a control group (n=6 each). Immunization of New Zealand white rabbits was used to prepare rabbit anti-porcine red blood cell antibodies, and rabbit anti-porcine red blood cell serum was separated. The neonatal pigs in the experimental group were given an intravenous injection of rabbit anti-porcine red blood cell serum (5 mL), and those in the control group were given an intravenous injection of normal saline (5 mL). Venous blood samples were collected every 6 hours for routine blood test and liver function evaluation.

RESULTSThe experimental group had a significantly higher serum bilirubin level than the control group at 18 hours after the injection of rabbit anti-porcine red blood cell serum (64±30 μmol/L vs 20±4 μmol/L; P<0.05). In the experimental group, the serum bilirubin level reached the peak at 48 hours (275±31 μmol/L), and decreased significantly at 96 hours after the injection (95±17 μmol/L), but all significantly higher than that in the control group (P<0.05). At 18 hours after the injection, the experimental group had a significantly lower red blood cell (RBC) count than the control group [(4.58±0.32)×10(12)/L vs (5.09±0.44)×10(12)/L; P<0.05]; at 24 hours, the experimental group showed further reductions in RBC count and hemoglobin level and had significantly lower RBC count and hemoglobin level than the control group [RBC: (4.21±0.24)×10(12)/L vs (5.11±0.39)×10(12)/L, P<0.05; hemoglobin: 87±3 g vs 97±6 g, P<0.05]. The differences in RBC count and hemoglobin level between the two groups were largest at 36-48 hours.

CONCLUSIONSThe neonatal pig model of hemolytic jaundice simulates the pathological process of human hemolytic jaundice well and provides good biological and material bases for further investigation of neonatal hemolysis.

Animals ; Animals, Newborn ; Bilirubin ; blood ; Disease Models, Animal ; Erythrocyte Count ; Female ; Hemoglobins ; analysis ; Jaundice ; etiology ; Male ; Rabbits ; Swine

OBJECTIVETo evaluate the in vitro anti-hypertrophic effect of total Glycosides of Ranunculus Japonius (TGRJ).

METHODSNeonatal rat cardiomyocytes were cultured and hypertrophy was induced by administrating isoproterenol (ISO, 10 µmol/L) or angiotensin 2 (Ang 2, 1 µmol/L) for 48 hours. In the treatment groups, cells were pretreated with TGRJ (0.3 g/L) for 30 minutes prior to hypertrophic stimuli. The anti-hypertrophic effects of TGRJ were examined by measuring cell size, total protein content, and protein synthesis. Intracellular free Ca(2+) concentration ([Ca(2+)]i) was evaluated using fluorescence dye Fura-2/AM. Sacroplasmic/endoplasmic reticulum Ca(2+) ATPase 2a (SERCA2a), atrial natriuretic peptide (ANP), B-type natriuretic peptide (BNP), and beta-myosin heavy chain (β-MHC) protein expression levels were measured by Western blotting . SERCA2a activity was assayed by p-nitrophenal phosphate disodium salt hexahydrate method.

RESULTSIncreased cell size, total protein content, and protein synthesis following ISO or Ang 2 stimulation were significantly inhibited by pretreatment with TGRJ (all P<0.05). This anti-hypertrophic effect of TGRJ was confirmed by its suppressing effect on elevated expression of the three hypertrophic related genetic markers, ANP, BNP, and β-MHC. In addition, TGRJ inhibited ISO or Ang 2 induced up-regulation of [Ca(2+)]i under chronic but not acute conditions. And ISO or Ang 2 induced down-regulation of SERCA2a expression and activity was also effectively rectified by TGRJ pretreatment.

CONCLUSIONSThe results of present study suggested that TGRJ could prevent ISO or Ang 2 induced cardiac hypertrophy through improving chronic [Ca(2+)]i disorder, might via normalizing SERCA2a expression and activity.

Animals ; Animals, Newborn ; Calcium ; metabolism ; Cells, Cultured ; Glycosides ; analysis ; pharmacology ; Myocytes, Cardiac ; drug effects ; metabolism ; pathology ; Ranunculus ; chemistry ; Rats

OBJECTIVETo investigate the short-term effects of flurothyl-induced neonatal recurrent seizures on gamma-aminobutyric acid A receptor (GABAAR) alpha1 and beta2 subunit expression in the rat brain, and to study the relationship between the alterations of GABAAR subunits in the developing brain and seizure-induced brain injury.

METHODSSixty-four 7-day-old Sprague-Dawley rats were randomly divided into two groups: control and seizure. Seizures were induced by inhalant flurothyl daily for six consecutive days. The expression of GABAAR alpha1 and beta2 subunits protein in the cerebral cortex and the hippocampus were detected by Western blot and immunohistochemistry method 1 and 7 days after recurrent seizures.

RESULTSCompared to the control, the accumulated optical density (AOD) of GABAAR alpha1 subunit immunoreactivity (IR) in the parietal cortex, the CA3-CA4 regions and the dentate gyrus in seizure rats increased significantly 1 day after recurrent seizures (P<0.05). The AOD of GABAAR alpha1 subunit IR in the parietal cortex, the CA1-CA4 regions and the dentate gyrus in seizure rats increased significantly 7 days after recurrent seizures compared with the control (P<0.05). The expression of GABAAR alpha1 subunit in the hippicampus and the cerebral cortex increased significantly in seizure rats compared with that in control rats 1 and 7 days after recurrent seizures. After 7 days of recurrent seizures, the AOD of GABAAR beta2 subunit IR in the CA1-CA2 regions increased significantly in the seizure group compared with that in the control group (P<0.05), but the AOD of GABAAR beta2 subunit IR in the thalamus decreased significantly in the seizure group compared with that in the control group (P<0.05). The expression of GABAAR beta2 subunit protein in the hippocampus increased significantly in the seizure group compared with that in the control group 7 days after recurrent seizures (P<0.05).

CONCLUSIONSRecurrent neonatal seizures may result in the short-term alterations of GABAAR alpha1 and beta2 subunits expression in the cerebral cortex and the hippocampus in rats, suggesting the alterations of GABAAR subunit expression may be related to the developing brain injury following recurrent seizures.

Animals ; Animals, Newborn ; Blotting, Western ; Brain Chemistry ; Immunohistochemistry ; Rats ; Rats, Sprague-Dawley ; Receptors, GABA-A ; analysis ; Recurrence ; Seizures ; metabolism

OBJECTIVETo study the effects of excessive fluoride on type I collagen in rat developmental dentine.

METHODSEighty SD rats, 5 days old, were divided into experimental and control groups, 40 in each group. The experimental group received subcutaneous injection of 0.2% NaF every 4 days (the dose was 2 mg NaF per kg body wt). The same volume of 0.9% NaCl was used in the control. Twenty rats in each group were killed 4 days after the second and the seventh injection respectively. The expression of type I collagen was assayed with immunohistochemical technique.

RESULTS4 out of 20 rats after two injections showed abnormal distribution of type I collagen (dense stain of collagen in the odontoblast, aggregation of collagen in the dentine and disordered arrangement of collagen in the predentine; All 20 rats after seven injections showed abnormal distribution of type I collagen.

CONCLUSIONExcessive fluoride may affect the metabolism of type I collagen in rat developmental dentine.

Animals ; Animals, Newborn ; Collagen Type I ; analysis ; Dentin ; chemistry ; drug effects ; growth & development ; Fluorides ; toxicity ; Immunohistochemistry ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo investigate the role of miRNA-210 in hypoxic-ischemic brain edema in neonatal rats.

METHODSA total of 80 neonatal rats were randomly divided into control group, normal saline group, miRNA-210 expression inhibition group, and miRNA-210 overexpression group, with 20 rats in each group. Each group was randomly divided into sham-operation group and hypoxia-ischemia (HI) group, with 10 rats in each group. The neonatal rats in the HI group were treated with ligation of the left common carotid artery and then put in a hypoxia cabin with mixed gas of 8% O2 and 92% N2 for 2 hours; those in the sham-operation group were treated with isolation of the left common carotid artery only, without ligation or hypoxia treatment. After HI or sham-operation, the rats in the normal saline group, miRNA-210 expression inhibition group, and miRNA-210 overexpression group were intracranially injected with normal saline (2.5 mg/kg), miRNA-210 inhibitor (2.5 mg/kg), and miRNA-210 mimic (2.5 mg/kg) respectively. No treatment was given to the rats in the control group. The rats were sacrificed three days later, and the left brain tissue was harvested. Fluorescent quantitative PCR was used to measure the expression of miRNA-210; the dry-wet weight method was used to measure the water content of brain tissue; hematoxylin and eosin staining was used to observe the histomorphological changes in the brain.

RESULTSThe HI groups showed significant reductions in the expression of miRNA-210 and significant increases in the water content of brain tissue compared with the corresponding sham-operation groups (P<0.05). Compared with the normal saline HI group, the miRNA-210 expression inhibition HI group showed a significant reduction in the expression of miRNA-210 and a significant increase in the water content of brain tissue (P<0.05), and the miRNA-210 overexpression HI group showed a significant increase in the expression of miRNA-210 and a significant reduction in the water content of brain tissue (P<0.05). The results of hematoxylin and eosin staining suggested that the miRNA-210 expression inhibition HI group showed marked edema, and the miRNA-210 overexpression HI group showed a significant improvement in edema.

CONCLUSIONSNeonatal rats show down-regulated expression of miRNA-210 after HI, suggesting that miRNA-210 may be involved in the development and progression of hypoxic-ischemic brain edema in neonatal rats.

Animals ; Animals, Newborn ; Brain Edema ; etiology ; Female ; Hypoxia-Ischemia, Brain ; etiology ; Male ; MicroRNAs ; analysis ; physiology ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo screen differentially expressed brain proteins with proteomic method in cerebral cortex of neonatal rats with congenital hypothyroidism.

METHODFrom the 13th day of gestation, pregnant Wistar rats from the experimental group were given intragastrically with 2.5 ml of 1% propylthiouracil daily. Cerebral cortex specimens were collected from the control and hypothyroidism neonatal rats. Two-directional electrophoresis (2-DE) was applied to analyze protein expression diversities between the euthyroid and hypothyroidism neonatal rat cerebral cortex. Protein spots with significantly different expression were screened and identified by mass spectrometry. Radioimmunoassay (RIA) was used to analyze serum FT(3), FT(4) levels of each groups.

RESULTThe body weight of hypothyroid neonatal rats were lower than those in the corresponding control group (t = -8.07, P < 0.01). The FT(3) levels of hypothyroid neonatal rats were lower than those in the corresponding control group (t = 5.39, P < 0.01). The FT(4) levels of hypothyroid neonatal rats were lower than those in the corresponding control group (t = 7.62, P < 0.01). Stable 2-DE maps of normal and CH neonatal rat were constantly obtained. The maps were analyzed by software. Seven protein spots with high reproducibility, high resolution and significantly different expression were chosen and identified by mass spectrometry, including collapsing response mediator protein 2, actin related protein 2/3 complex subunit 5, ubiquitin-conjugating enzyme E2-25K, ATP synthase subunit d, Cu-Zn superoxide dismutase, synuclein alpha, and nucleoside diphosphate kinase.

CONCLUSIONThe value of this research is demonstrated here by the identification of several proteins known to be associated with nerve synapse structures formation, cell survival, metabolism, cell signal transduction, neural differentiation and nerve growth in the central nervous system. Furthermore this study identified several proteins except for collapsing response mediator protein 2 and Cu-Zn superoxide dismutase that have not previously been described in the literature and which may play an important role as either sensitive biomarkers of brain dysfunction caused by congenital hypothyroidism. In congenital hypothyroidism, brain development retardation may be related with some important processes, including abnormal synaptic formation, excess ROS production and apoptosis. The above-mentioned proteins may play critical roles in the processes, which provide valuable clues to clarify the pathogenesis of brain developmental disorders induced by congenital hypothyroidism.

Animals ; Animals, Newborn ; metabolism ; Brain ; metabolism ; Cerebral Cortex ; metabolism ; Congenital Hypothyroidism ; metabolism ; Female ; Pregnancy ; Proteome ; analysis ; Proteomics ; Rats

OBJECTIVETo study the effect of PINK1 (phosphatase and tensin homolog deleted on chromosome ten induced putative kinase 1) gene on cell apoptosis and cell autophagy in neonatal mice with hypoxic-ischemic brain damage (HIBD).

METHODSSeventy-two wild-type C57BL/6 mice and 72 PINK1 gene knockout neonatal C57BL/6 mice were randomly divided into four groups: sham-operated wild-type (SWT), HIBD model wild-type (MWT), sham-operated knockout (SKO) and HIBD model knockout (MKO). HIBD model was prepared by low oxygen exposure for 2.5 hours after right carotid artery ligation. After 24 hours of hypoxia-ischemia treatment, TTC (2,3,5-triphenyl four azole nitrogen chloride) staining was used to measure brain infarct volume. The immunohistochemical staining was used to measure the expression of cell apoptosis protein cleaved-caspase-3 (CC3) in brain tissues. The TUNEL method was used to measure cell apoptosis. The immunofluorescence staining and Western blot were used to measure the expression of cell autophagy protein LC3.

RESULTSCompared with the MWT group, the infarct volume of brain tissues was markedly reduced in the MKO group (P<0.05), the number of apoptotic cells and the cell apoptosis index were markedly decreased in the MKO group (P<0.05), the expression of apoptosis protein CC3 was significantly reduced in the MKO group (P<0.05), the expression of cell autophagy protein LC3 was significantly decreased in the MKO group, and the autophagy indicator LC3II/LC3I was also markedly reduced in the MKO group (P<0.05).

CONCLUSIONSPINK1 gene knockout can protect neonatal mice from HIBD.

Animals ; Animals, Newborn ; Apoptosis ; Autophagy ; Female ; Hypoxia-Ischemia, Brain ; pathology ; Male ; Mice ; Mice, Inbred C57BL ; Protein Kinases ; genetics ; Repressor Proteins ; analysis ; Tumor Suppressor Proteins ; analysis