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<p><b>OBJECTIVE</b>To investigate the effects of prenatal alcohol exposure on rhythmic respiratory discharge activity (RRDA) in the medullary slices of neonatal rats.</p><p><b>METHODS</b>Ten pregnant female SD rats were exposed to 0, 4%, 6%, 8%, and 10% alcohol in drinking water from 1 week before till 3 days after delivery. The medullary slices of the neonatal rats containing the medial region of the nucleus retrofacialis (mNRF) with the hypoglossal nerve rootlets were prepared and perfused with modified Kreb's solution to record RRDA from the hypoglossal nerve rootlets using suction electrodes.</p><p><b>RESULTS</b>No significant difference was found in RRDA in 50 min among the neonatal rats with prenatal exposure to 0, 4%, 6%, and 8% alcohol, but the RRDA in 10% alcohol exposure group became irregular. Prenatal exposure to increased alcohol concentrations caused attenuated RRDA attenuated in the neonatal rats, shown by shortened inspiratory time (TI), decreased respiratory frequency (RF), and reduced integral amplitude (IA) as compared with those in the control group.</p><p><b>CONCLUSION</b>Prenatal alcohol exposure inhibits RRDA in medullary slices of neonatal rats, which might be a mechanism by which maternal alcohol exposure causes suppressed offspring respiratory functions.</p>
Subject(s)
Animals , Female , Pregnancy , Rats , Animals, Newborn , Ethanol , Hypoglossal Nerve , Medulla Oblongata , Prenatal Exposure Delayed Effects , Rats, Sprague-Dawley , RespirationABSTRACT
To evaluate the protective effects of intravitreal injection of cannabinoid HU - 211 for optic nerve in glaucoma rats, providing the experimental evidence in the treatment of glaucoma optic nerve injury. ●METHODS: Glaucoma rats (18 eyes) were modeled by electric coagulation sclera surface vein and randomized into 3 groups, group A received intravitreal injection of 1mg/ 0. 1mL cannabinoid HU - 211 every other day respectively; group B was given intravitreal injection of 0. 1mL water every other day, group C was high intraocular pressure (lOP) group, 6 eyes were randomly selected for blank control group ( group D). lOP was observed every day. The rats were sacrificed after treatment 4wk, froze retina section, HE stain. The density fluctuation of retinal ganglion cell ( RGC ) neurons assessment the optic nerve of rat model with chronic high lOP glaucoma were measured. ●RESULTS: The apoptosis and damage degree of RGC in group B was obviously higher than that in group A, with statistically significant difference (P0. 05). ●CONCLUSlON: lntravitreal injection of cannabinoid HU-211 shows obvious protective effect on optic nerve in glaucom rat models.
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Objective To explore the modulatory effect of 5-HT2A receptors on the discharge activities of inspiratory neurons in medial region of nucleus retrofacialis of neonatal rats. Methods Experiments were performed in vitro brainstem slice preparations from neonatal rats. These preparations included the medial region of nucleus retrofacialis with the hypoglossal nerve rootlets retained. The rhythmic discharges of the inspiratory neurons and activities of the hypoglossal nerve rootlets were simultaneously recorded by using microelectrodes and suction electrodes, respectively. Roles of 5-HT2A receptors in modulation of the discharge activities of inspiratory neurons were investigated by administration of the 5-HT2A receptor agonist 1-(2,5-dimethoxy-4-iodopbenyl)-2-aminopropane (DOI), and its specific antagonist ketanserine dissolved in modified Kreb's solution for perfused slices. Results In DOI group, the inspiratory time (TI) was (0.864±0.07)s, expiratory time (TE) was (10.78±1.06)s, respiratory cycle (RC) was (11.79±1.64)s, integral amplitude (IA) was (357.98±37.21)(μV·s) and the peak discharge frequency (PF) was (37.83±3.66)Hz. In control group, they were (0.68±0.06)s, (13.89±2.14)s, (14.77±1.92)s, (273.57±24.39)(μV·s), and (29.92±4.50)Hz, there were significant differences between the 2 groups (Pa<0.01). In ketanserine group, TI was (0.55±0.07)s, TE and RC were (18.43±3.28)s and (20.17+2.91)s respectively, IA and PF were (214.37±33.52)(μV·s) and (22.17±3.92)Hz, there were significant differences between ketanserine group and DOI, control group (Pa<0.01). Conclusion 5-HT2A receptors take part in modulate the discharge activities of inspiratory neurons in neonatal rat brainstem slices.
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Objective To explore the relationship of c-fos protein and cell apoptosis by observing the expression of c-fos protein in hippocampus of newborn rat with hypoxic-ischemic brain damage(HIBD).Methods Forty-eight 7-day SD neonatal rats were randomly divided into control group(n=6) and experiment group(n=42).The models of HIBD were established in neonatal rats by inhaling the mixed gases of 920 mL/L N2 and 80 mL/L O2,and the animals were sacrificed by dislocation their heads at different time points(0.5,1,3,6,12,24,48,72 h),then the hippocampus were dissected by morphological analysis.Results The apoptotic cells appeared at the time point of 3 h,and reached the peak at 48 h,then decreased.The positive cell of c-fos protein increased from the time point of 30 min and reached the peak at 2 h and then decreased gradually,and there was a contrary tendency between the expression of c-fos protein and the number of damaged brain cells by HIBD(r=-0.57 P
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Objective To analyze the type of acid-base disturbance caused by severe pneumonia in newborn infants .Methods Venous blood of neonate with severe pneumonia(SP group) were collected to detect serum electrolyte and blood gas analysis 12 hours before and after oxygen therapy .The results of serum electrolyte and blood gas were compared 12 hours before and after oxygen therapy ,and the results of acid-base disturbance between SP group and control groups were compared.Results There were mostly metabolic acidosis incorporated respiratory acidosis in all neonate in SP group,which were with increased anion gap (AG) and obviously higher than that of control group(t=1.27 P
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Objective To explore the modulation roles of gamma-aminobutyric acid A(GABAA) receptor on respiratory rhythmical discharge activity in brainstem slice of neonatal rats.Methods Experiments were performed on in vitro neonatal rats brainstem slices.The slices containing the medial region of the nucleus retrofacialis(mNRF)with the hypoglossal nerve rootlets retained was prepared in which the respira-tory-related rhythmic discharge activity(RRDA)were recorded from hypoglossal nerve rootlets by suction electrode.The possible role of GABAA receptor on RRDA was investigated by administration of GABA and its antagonist bicuculline in modified Kreb′s solution(MKS),for perfusion of the brainstem slices.Eighteen slices positive of RRDA were randomly divided into three equal groups:the first group of slices was perfused with different concentrations(10,20,40,60 ?mol/L) GABA and the most effective concentration was selected;the second group of slices was perfused with 10 ?mol/L bicuculline;the third group of slices was perfused with 10 ?mol/L bicuculline plus 40 ?mol/L GABA.The RRDA in 3 groups were observed.Results GABA decreased RRDA,40 ?mol/L was the most effective concentration.It shortened inspiratory time(TI),decreased integral amplitude(IA),prolonged respiratory cycle(RC) and expiratory time(TE) respectively.By contrast,10 ?mol/L bicuculline produced opposite effects on RRDA,it prolonged TI,increased IA,shortened RC and TE respectively.40 ?mol/L GABA plus 10 ?mol/L bicuculline had no significant effects on RRDA.Conclusion GABA plays an important role in modulate RRDA of neonatal rats via GABAA receptor.