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Objective:To investigate the effects of unilateral ureteral obstruction on renal pelvic peristalsis and pacemaker cells in neonatal rats.Methods:An animal experimental study.Thirty-six 2-day-old newborn SD rats were randomly divided into the partial unilateral ureteral obstruction (PUUO) group, complete unilateral ureteral obstruction (CUUO) group, and sham operation group, with 12 rats in each group.One week after surgery, all rats were subjected to renal pelvic pressure (RPP) measurement by puncture.After measurement, the rats were euthanized, and their left renal pelvis and ureter were removed and fixed for histological examination.Parameters such as RPP, peristaltic wave frequency and amplitude at different perfusion speeds were recorded and compared, and the changes in pacemaker cells (atypical smooth muscle cells and Cajal-like interstitial cells) were also compared.The independent samples t-test was used for comparison between 2 groups, and the one-way ANOVA of variance was used for comparison among 3 groups. Results:In the sham operation group, the RPP increased gradually with the increase of perfusion speed; the frequency of peristaltic waves rose rapidly and then dropped after reaching the highest level with the increase of perfusion speed; similarly, the amplitude of peristaltic waves first increased and then decreased as the perfusion speed increased.In the PUUO group, the RPP increased rapidly with the increase of perfusion speed, higher than that in the sham operation group; the frequency of peristaltic waves was higher than that in the sham operation group, and it was relatively constant under the perfusion speed of 40 mL/h, but when the perfusion speed increased again, the frequency began to decline; the amplitude of peristaltic waves increased quickly and then declined at a faster rate than the sham operation group with the increase of perfusion speed.In the CUUO group, the basic RPP was 12 cmH 2O(1 cmH 2O=0.098 kPa); at the perfusion speed of 5 mL/h, the RPP rose gradually, and no plateau appeared; when the RPP reached 73 cmH 2O, the perfusate retrograded from the side of the puncture needle, then the RPP slightly decreased and then balanced, and no regular peristaltic waves were observed in the renal pelvis throughout the whole perfusion process.Immunofluorescence staining analysis showed the pacemaker cells were all located in the smooth muscle of the renal pelvic wall.The sham operation group had the highest positive rate, followed by the PUUO group and then the CUUO group. Conclusions:Ureteral obstruction has a significant impact on the peristalsis of the renal pelvis, and its impact on the peristaltic wave frequency and amplitude and RPP can be predicted.The reduction of pacemaker cells in the renal pelvis may be involved in the changes of renal pelvic peristalsis caused by ureteral obstruction, but further research is needed on how pacemaker cells regulate the peristalsis of the renal pelvis and ureter.
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Objective To investigate the expression of long non - coding RNA(lncRNA)in neonatal rats with hypoxic - ischemic brain damage(HIBD). Methods SD rats of 10 postnatal days were divided into the sham -operated control and the hypoxic - ischemic(HI)group. At 24 h after HI,the animals were sacrificed. HE staining was used to assess histopathological damage. Microarray was used to detect the expression of lncRNA and mRNA in hypoxic -ischemic and sham control brain. Real - time PCR was used to verify the microarray result. The differentially expressed mRNA was analyzed by gene ontology(GO),pathway and coding - noncoding RNA co - expression(CNC)network analysis. Results HE staining showed that cells in HI brains became swollen and disordered with ambiguous cell struc-ture. Microarray data demonstrated that 322 lncRNAs and 375 mRNAs were significantly altered in the neonatal brains following hypoxic - ischemic injury compared with sham control(P ﹤ 0. 05). The real - time PCR results agreed with those of the microarray. GO analysis showed that the most enriched biological process associated with the upregulated mRNA had response to wounding,whereas the biological process mostly enriched among the downregulated mRNA was so-matic stem cell division. Pathway analysis indicated that upregulated mRNA was primarily corresponded with cytokine -cytokine receptor interaction pathway and that downregulated mRNA mainly correlated to axon guidance pathway. CNC network analysis demonstrated that 177 lncRNAs were correlated to the expression of mRNA involved in inflammation and cell death(P ﹤0. 05). Conclusions HI injury significantly influences cerebral lncRNA and mRNA expression profiles in the neonatal rat brains. Deregulated lncRNAs might contribute to the pathogenesis of HIBD via interacting with mRNA.
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Objective To know about the effect and significance of endothelin-1 (ET-1) in pathogenesis of hypoxic pulmonary hypertension(HPH) in neonatal rats.Methods The 120 newborn Wistar rats were randomly divided into hypoxic group and control group,and the rats of hypoxic group were made into HPH model.Mean pulmonary arterial pressure(mPAP) was measured on day 3,5,7,10,14 and 21 after hypoxia.The morphological change of pulmonary vessels were observed,and pulmonary vascular remodeling indexes were also obtained,including the ratio of middle wall thickness to external diameter of small pulmonary arteries (MT％) and the ratio of media cross-section area to total cross-sectional area of small pulmonary arteries(MA％).Immunohistochemistry and Western blot tests were done to determine the expression of ET-1 in lung tissue.Results 1.After hypoxia for 3,5,7,10,14,21 days,the levels of mPAP in hypoxia group[(8.492 ± 1.548) mm Hg,(10.022 ± 1.182) mm Hg,(11.470 ± 2.868) mm Hg,(16.842 ±2.154) mm Hg,(12.824 ± 2.859) mm Hg,(21.036 ± 2.590) mm Hg; 1 mm Hg =0.133 kPa] were significantly higher than those in control group[(5.141 ± 1.022) mm Hg,(8.137 ± 1.057) mm Hg,(8.730 ±0.868) mm Hg,(12.125 ±2.541) mm Hg,(8.920 ±0.744) mm Hg,(11.156 ±1.644) mm Hg] (all P ＜0.05).2.Seven days after hypoxia exposure,small pulmonary arterials remodeling was observed.MT％ [(53 ± 11) ％] and MA％ [(60 ± 9) ％]in hypoxia group were also significantly higher than those in control group [(49 ± 11) ％,(54 ± 8) ％] (all P ＜ 0.05).3.The results of immunohistochemistry:the expression intensities of ET-1 were significantly higher in hypoxia group (0.614,0.613,0.651) after hypoxia for 3,5,7 days than those in control group (0.433,0.386,0.369) (all P ＜ 0.05).4.The results of Western blot:the levels of ET-1 were significantly higher in hypoxia group(4.885 ± 1.391,4.434 ± 1.726,6.309 ± 0.330,2.353 ± 0.961) after hypoxia for 3,5,7 and 10 days than those in control group (1.698 ± 0.794,1.454 ± 0.776,2.045 ± 0.668,0.766 ± 0.515) (all P ＜ 0.05).5.The results of correlation analysis:the total expression of ET-1 protein was positively correlated with the total level of mPAP on 3-7 days after hypoxia (r =0.459,P ＜ 0.05).However,the expression of ET-1 had no significant correlation with MT％ and MA％ (rMT =-0.041,rMA =0.322,all P ＞ 0.05).Conclusions The level of ET-1 in lung tissue of HPH newborn rats increased in the early stage after hypoxia exposure and no longer increased during the late stage,which indicated that hypoxia tolerance prevailed.ET-1 acted as an early reactive marker in the process of HPH development in neonatal rats and may be mainly associated with elevated mPAP,which further prompted that through valid means to inhibit the expression of ET-1 in the early stage of hypoxia,in which the prevention and treatment of this disease may be more effective.
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Objective To explore the expression of adrenomedulin(ADM) and its receptors mRNA in newborn rats with hypoxic-ischemic brain damage(HIBD).Methods Eighty 7-day-old Wistar neonatal rats were randomly assigned 10 groups,to the sham- operation group(the left common carotid artery without ligated and no hpoxia environment),HIBD different time points groups(0,2,4,6,8,10,12,24,48 hours).The expression of ADM mRNA was measured in cortex at different time points by the reverse-transcription polymerase chain reaction(RT-PCR).Results Expressions of ADM and its receptors mRNA in neonatal rats with HIBD increased,and after HIBD 2-4 hours,had a significant difference compared with the sharn-operation group,and reached the highest after HIBD 8-10 hours(P