Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 15 de 15
Filtrar
1.
Front Pediatr ; 12: 1287232, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38415211

RESUMO

Introduction: Extremely preterm infants (EPIs) have high morbidity and mortality, and are recommended to be born in a tertiary perinatal center (inborn). However, many EPIs in central China are born in lower-level hospitals and transferred postnatally, the outcomes of which remain to be investigated. Methods: EPIs admitted to the Department of Neonatology, Maternal and Child Health Hospital of Hubei Province from January 2013 to December 2022 were retrospectively recruited and divided into the control (inborn) and transfer groups (born in other hospitals). The neonatal and maternal characteristics, neonatal outcomes, and the treatment of survival EPIs were analyzed. Results: A total of 174 and 109 EPIs were recruited in the control and transfer groups, respectively. EPIs in the transfer group have a higher birth weight and a lower proportion of multiple pregnancies than the control group (all P < 0.05). The proportions of antenatal steroids, magnesium sulfate, cesarean delivery, premature rupture of membranes ≥18 h, gestational diabetes, and amniotic fluid abnormalities were lower in the transfer group (all P < 0.05). Survival rates (64.22% vs. 56.32%), proportions of severe periventricular-intraventricular hemorrhage (PIVH) (11.93% vs. 11.49%), severe bronchopulmonary dysplasia (sBPD) (21.05% vs. 20%), and severe retinopathy of prematurity (ROP) (24.77% vs. 20.11%) were similar in the transfer and control groups (all P > 0.05). However, the transfer group had higher proportions of severe birth asphyxia (34.86% vs. 13.22%, P < 0.001), PIVH (42.20% vs. 29.89%, P = 0.034), and extrauterine growth retardation (EUGR) (17.43% vs. 6.32%, P = 0.003). Less surfactant utilization was found in the transfer group among survival EPIs (70.00% vs. 93.88%, P < 0.001). Conclusion: EPIs born outside a tertiary perinatal center and transferred postnatally did not have significantly higher mortality and rates of severe complications (severe PIVH, severe ROP, and sBPD), but there may be an increased risk of severe asphyxia, PIVH and EUGR. This may be due to differences in maternal and neonatal characteristics and management. Further follow-up is needed to compare neurodevelopmental outcomes, and it is recommended to transfer the EPIs in utero to reduce the risk of poor physical and neurological development.

2.
Pediatr Neonatol ; 64(5): 562-569, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37105821

RESUMO

BACKGROUND: Birth asphyxia causes hypoxia or inadequate perfusion to the organs of newborns, leading to metabolism dysfunctions including blood glucose disorders. METHODS: Neonates with and without birth asphyxia were retrospectively recruited from 53 hospitals in Hubei Province from January 1 to December 31, 2018. In summary, 875, 1139, and 180 cases in the control group, the mild asphyxia group, and the severe asphyxia group were recruited, respectively. Neonatal blood glucose values at postnatal 1, 2, 6, and 12 h (time error within 0.5 h was allowed) were gathered from the medical records. RESULTS: The incidence rates of hyperglycemia in the control group, the mild asphyxia group and the severe asphyxia group were 2.97%, 7.90%, and 23.33%, respectively (p < 0.001). Additionally, the incidence rates of hypoglycemia in the three groups above were 3.66%, 4.13%, and 7.78%, respectively (p = 0.042). The blood glucose values of neonates with hypoglycemia in the asphyxia group were lower than in the control group (p = 0.003). Furthermore, the blood glucose values of neonates with hyperglycemia were highest in the severe asphyxia group (p < 0.001). There were 778 and 117 cases with blood glucose records at four predefined time points in the mild and severe asphyxia group, respectively. The incidence of blood glucose disorders in the mild asphyxia group significantly decreased from postnatal 6 h (p<0.05). However, we found no obvious changes of the incidence of glucose disorders within postnatal 12 h in the severe asphyxia group (p = 0.589). CONCLUSION: Birth asphyxia is likely to cause neonatal blood glucose disorders, both hypoglycemia and hyperglycemia, during the early postnatal life. The neonates with severe asphyxia have higher incidence, worse severity and longer duration of blood glucose disorders than neonates with mild asphyxia.


Assuntos
Asfixia Neonatal , Hiperglicemia , Hipoglicemia , Doenças do Recém-Nascido , Humanos , Recém-Nascido , Glicemia , Asfixia , Estudos Retrospectivos , Asfixia Neonatal/epidemiologia , Doenças do Recém-Nascido/epidemiologia , Hipoglicemia/epidemiologia , Hipoglicemia/etiologia , Hiperglicemia/epidemiologia , China/epidemiologia
3.
Zhongguo Dang Dai Er Ke Za Zhi ; 24(11): 1195-1201, 2022 Nov 15.
Artigo em Chinês | MEDLINE | ID: mdl-36398543

RESUMO

OBJECTIVES: To investigate the influence of early-stage hypotension defined as mean arterial pressure (MAP)0.05).The univariate analysis showed that the poor short-term prognosis was related to birth of cesarean section, gestational age, an Apgar score of ≤ 5 at 5 minutes, use of vasoactive drugs within 72 hours, mechanical ventilation within 72 hours, and hypotension under the two definitions (P<0.05).The multivariate logistic regression showed that hypotension based on either definition was not an independent risk factor for poor prognosis (P>0.05). CONCLUSIONS: Hypotension based on either definition is not an independent risk factor for short-term poor prognosis in preterm infants with a gestational age of <32 weeks. Hypotension defined by MAP<30 mmHg might be more sensitive than that defined by MAP

Assuntos
Hipotensão , Recém-Nascido Prematuro , Lactente , Criança , Recém-Nascido , Humanos , Gravidez , Feminino , Idade Gestacional , Estudos Prospectivos , Cesárea , Hipotensão/etiologia , Prognóstico , Hemorragia Cerebral
4.
Front Mol Neurosci ; 15: 871974, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35465090

RESUMO

The tumor suppressor p53 plays a crucial role in embryonic neuron development and neurite growth, and its involvement in neuronal homeostasis has been proposed. To better understand how the lack of the p53 gene function affects neuronal activity, spine development, and plasticity, we examined the electrophysiological and morphological properties of layer 5 (L5) pyramidal neurons in the primary somatosensory cortex barrel field (S1BF) by using in vitro whole-cell patch clamp and in vivo two-photon imaging techniques in p53 knockout (KO) mice. We found that the spiking frequency, excitatory inputs, and sag ratio were decreased in L5 pyramidal neurons of p53KO mice. In addition, both in vitro and in vivo morphological analyses demonstrated that dendritic spine density in the apical tuft is decreased in L5 pyramidal neurons of p53KO mice. Furthermore, chronic imaging showed that p53 deletion decreased dendritic spine turnover in steady-state conditions, and prevented the increase in spine turnover associated with whisker stimulation seen in wildtype mice. In addition, the sensitivity of whisker-dependent texture discrimination was impaired in p53KO mice compared with wildtype controls. Together, these results suggest that p53 plays an important role in regulating synaptic plasticity by reducing neuronal excitability and the number of excitatory synapses in S1BF.

5.
Zhongguo Dang Dai Er Ke Za Zhi ; 23(12): 1208-1213, 2021 Dec 15.
Artigo em Inglês, Chinês | MEDLINE | ID: mdl-34911602

RESUMO

OBJECTIVES: To study the effect of glucose metabolism disorders on the short-term prognosis in neonates with asphyxia. METHODS: A retrospective analysis was performed on the medical data of the neonates with asphyxia who were admitted to 52 hospitals in Hubei Province of China from January to December, 2018 and had blood glucose data within 12 hours after birth. Their blood glucose data at 1, 2, 6, and 12 hours after birth (with an allowable time error of 0.5 hour) were recorded. According to the presence or absence of brain injury and/or death during hospitalization, the neonates were divided into a poor prognosis group with 693 neonates and a good prognosis group with 779 neonates. The two groups were compared in the incidence of glucose metabolism disorders within 12 hours after birth and short-term prognosis. RESULTS: Compared with the good prognosis group, the poor prognosis group had a significantly higher proportion of neonates from secondary hospitals (48.5% vs 42.6%, P<0.05) or with severe asphyxia (19.8% vs 8.1%, P<0.05) or hypothermia therapy (4.8% vs 1.5%, P<0.05), as well as a significantly higher incidence rate of disorder of glucose metabolism (18.8% vs 12.5%, P<0.05). Compared with the good prognosis group, the poor prognosis group had a significantly higher incidence rate of disorder of glucose metabolism at 1, 2, and 6 hours after birth (P<0.05). The multivariate logistic regression analysis showed that recurrent hyperglycemia (adjusted odds ratio=2.380, 95% confidence interval: 1.275-4.442, P<0.05) was an independent risk factor for poor prognosis in neonates with asphyxia. CONCLUSIONS: Recurrent hyperglycemia in neonates with asphyxia may suggest poor short-term prognosis, and it is necessary to strengthen the early monitoring and management of the nervous system in such neonates.


Assuntos
Asfixia Neonatal , Hiperglicemia , Asfixia , Asfixia Neonatal/complicações , Asfixia Neonatal/epidemiologia , Humanos , Recém-Nascido , Prognóstico , Estudos Retrospectivos
6.
Ann Transl Med ; 9(5): 382, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33842603

RESUMO

BACKGROUND: There is an emerging literature on the mental health of both pre- and post-partum mothers during the coronavirus disease 2019 (COVID-19) pandemic. METHODS: As of April 1, 2020, 23 mothers confirmed with COVID-19, 15 mothers suspected with COVID-19 but with negative polymerase chain reaction tests, and 33 mothers without COVID-19 (Control Group) were recruited for a study from Hubei Province in China. The Maternal Postnatal Attachment Scale (MPAS), the Zung Self-rating Anxiety Scale, and the Zung Self-rating Depression Scale were applied to investigate the attachment of mothers to their neonates and the postpartum mental health of mothers within the first 3 months after delivery (between 20 to 89 days). RESULTS: The period of mother-child separation among the confirmed group (33.9±20.9 days) was significantly longer than that of suspected group (16.7±12.2 days) and control group (10.7±8.4 days). The total score of the MPAS in mothers confirmed with COVID-19 (45.5±4.2) was significantly lower (indicating less mother-child attachment) than that in the suspected (50.5±4.7) and control (48.8±4.6) groups. A negative correlation was noted between the mother-child separation time and the MPAS scores, including the subscale scores of attachment (MPAS acore: Spearman's ρ =-0.33, 95% CI: -0.095 to -0.538, P=0.005; Subscale score of attachment: Spearman's ρ =-0.40, 95% CI: -0.163 to -0.592, P=0.001). The incidence of postpartum anxiety in the confirmed, suspected and control groups was 4.3%, 6.7% and 12.1%, respectively; and the incidence of postpartum depression was 39.1%, 33.3% and 30.3%, respectively. No significant difference was found with regards to maternal postpartum anxiety and depression among the three groups. CONCLUSIONS: Decreased mother-child attachment found among mothers confirmed with COVID-19, indicates that further intervention is needed to ensure mother-child interaction to appropriately develop attachment. Mother-child attachment experienced disruption due to prolonged mother-child separation necessitated by the COVID-19 management protocol, which needs to be revised to reduce prolonged mother-child separation. Additionally, mothers with and without COVID-19 suffered a high incidence of depression, which warrants further mental health investment for pregnant mothers during the COVID-19 pandemic.

7.
World J Pediatr ; 17(3): 253-262, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33844176

RESUMO

BACKGROUND: Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an emerging disease. The consequences of SARS-CoV-2 exposure in infants remain unknown. Therefore, this study aims to investigate whether neonates born to mothers with COVID-19 have adverse brain development. METHODS: This multicenter observational study was conducted at two designated maternal and children's hospitals in Hubei Province, mainland China from February 1, 2020 to May 15, 2020. Neonates born to mothers with COVID-19 were enrolled. Brain magnetic resonance imaging (MRI) findings, and volumes of grey and white matters, and physical growth parameters were observed at 44 weeks corrected gestational age. RESULTS: Of 72 neonates born to mothers with COVID-19, 8 (11%) were diagnosed with COVID-19, 8 (11%) were critically ill, and no deaths were reported. Among the eight neonates that underwent brain MRI at corrected gestational age of 44 weeks, five neonates were diagnosed with COVID-19. Among these five neonates, three presented abnormal MRI findings including abnormal signal in white matter and delayed myelination in newborn 2, delayed myelination and brain dysplasia in newborn 3, and abnormal signal in the bilateral periventricular in newborn 5. The other three neonates without COVID-19 presented no significantly changes of brain MRI findings and the volumes of grey matter and white matter compared to those of healthy newborns at the equivalent age (P > 0.05). Physical growth parameters for weight, length, and head circumference at gestational age of 44 weeks were all above the 3rd percentile for all neonates. CONCLUSIONS: Some of the neonates born to mothers with COVID-19 had abnormal brain MRI findings but these neonates did not appear to have poor physical growth. These findings may provide the information on the follow-up schedule on the neonates exposed to SARS-CoV-2, but further study is required to evaluate the association between the abnormal MRI findings and the exposure to SARS-CoV-2.


Assuntos
Encéfalo/anormalidades , Encéfalo/diagnóstico por imagem , COVID-19/transmissão , Transmissão Vertical de Doenças Infecciosas , Imageamento por Ressonância Magnética , COVID-19/epidemiologia , China/epidemiologia , Feminino , Humanos , Recém-Nascido , Masculino , Pandemias , Gravidez , SARS-CoV-2
8.
Transl Pediatr ; 9(1): 51-60, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32154135

RESUMO

BACKGROUND: The newly identified 2019-nCoV, which appears to have originated in Wuhan, the capital city of Hubei province in central China, is spreading rapidly nationwide. A number of cases of neonates born to mothers with 2019-nCoV pneumonia have been recorded. However, the clinical features of these cases have not been reported, and there is no sufficient evidence for the proper prevention and control of 2019-nCoV infections in neonates. METHODS: The clinical features and outcomes of 10 neonates (including 2 twins) born to 9 mothers with confirmed 2019-nCoV infection in 5 hospitals from January 20 to February 5, 2020 were retrospectively analyzed. RESULTS: Among these 9 pregnant women with confirmed 2019-nCoV infection, onset of clinical symptoms occurred before delivery in 4 cases, on the day of delivery in 2 cases, and after delivery in 3 cases. In most cases, fever and a cough were the first symptoms experienced, and 1 patient also had diarrhea. Of the newborns born to these mothers, 8 were male and 2 were female; 4 were full-term infants and 6 were born premature; 2 were small-for-gestational-age (SGA) infants and 1 was a large-for-gestational-age (LGA) infant; there were 8 singletons and 2 twins. Of the neonates, 6 had a Pediatric Critical Illness Score (PCIS) score of less than 90. Clinically, the first symptom in the neonates was shortness of breath (n=6), but other initial symptoms such as fever (n=2), thrombocytopenia accompanied by abnormal liver function (n=2), rapid heart rate (n=1), vomiting (n=1), and pneumothorax (n=1) were observed. Up to now, 5 neonates have been cured and discharged, 1 has died, and 4 neonates remain in hospital in a stable condition. Pharyngeal swab specimens were collected from 9 of the 10 neonates 1 to 9 days after birth for nucleic acid amplification tests for 2019-nCoV, all of which showed negative results. CONCLUSIONS: Perinatal 2019-nCoV infection may have adverse effects on newborns, causing problems such as fetal distress, premature labor, respiratory distress, thrombocytopenia accompanied by abnormal liver function, and even death. However, vertical transmission of 2019-nCoV is yet to be confirmed.

9.
Lancet Reg Health West Pac ; 4: 100045, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34013217

RESUMO

BACKGROUND: The possibility of 2019 novel coronavirus disease (COVID-19) transmission to neonates through breast milk remains unverified. METHODS: This paper presents the interim results of a longitudinal study being carried out in Hubei province. As of 1 April 2020, 24 mothers confirmed with COVID-19, 19 mothers suspected with COVID-19 but Polymerase chain reaction negative, and 21 mothers without COVID-19 and their neonates have been recruited. Telephone follow-up was conducted to collect information on breastfeeding practices. Forty-four breast milk samples were collected from 16 of the 24 mothers with confirmed COVID-19 for the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) ribonucleic acid (RNA) and antibodies (IgM and IgG) testing. FINDINGS: The average mother-child separation time was 36•7 ± 21•1 days among mothers confirmed with COVID-19, significantly longer than that of the suspected group (16•6 ± 13•1 days) and control group (10•5 ± 8•2 days). Both the COVID-19 confirmed (58•3%) and suspected (52•6%) groups presented significantly lower rates of breastfeeding as compared with the control group (95•2%). All 44 breast milk samples tested negative for the SARS-CoV-2 nucleic acid. Thirty-eight breast milk samples underwent antibody testing and all tested negative for IgG. Twenty-one breast milk samples from 8 women tested positive for IgM, while the remaining samples from 11 women tested negative. INTERPRETATION: Considering the lack of evidence for SARS-CoV-2 transmission through breast milk, breastfeeding counselling along with appropriate hand hygiene precautions and facemasks should be provided to all pregnant women. FUNDING: The study was funded by the Hong Kong Committee for UNICEF.

10.
J Vis Exp ; (143)2019 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-30735185

RESUMO

Recent whole-cell patch-clamp studies from substantia gelatinosa (SG) neurons have provided a large body of information about the spinal mechanisms underlying sensory transmission, nociceptive regulation, and chronic pain or itch development. Implementations of electrophysiological recordings together with morphological studies based on the utility of acute spinal cord slices have further improved our understanding of neuronal properties and the composition of local circuitry in SG. Here, we present a detailed and practical guide for the preparation of spinal cord slices and show representative whole-cell recording and morphological results. This protocol permits ideal neuronal preservation and can mimic in vivo conditions to a certain extent. In summary, the ability to obtain an in vitro preparation of spinal cord slices enables stable current- and voltage-clamp recordings and could thus facilitate detailed investigations into the intrinsic membrane properties, local circuitry and neuronal structure using diverse experimental approaches.


Assuntos
Neurônios/fisiologia , Técnicas de Patch-Clamp/métodos , Substância Gelatinosa/citologia , Potenciais de Ação/fisiologia , Animais , Masculino , Ratos Sprague-Dawley , Transmissão Sináptica/fisiologia
11.
Front Cell Neurosci ; 12: 370, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30386213

RESUMO

Spinal lamina II (substantia gelatinosa, SG) neurons integrate nociceptive information from the primary afferents and are classified according to electrophysiological (tonic firing, delayed firing, single spike, initial burst, phasic firing, gap firing and reluctant firing) or morphological (islet, central, vertical, radial and unclassified) criteria. T-type calcium (Cav3) channels play an essential role in the central mechanism of pathological pain, but the electrophysiological properties and the cell-type specific distribution of T-type channels in SG neurons have not been fully elucidated. To investigate the electrophysiological and morphological features of T-type channel-expressing or -lacking neurons, voltage- and current-clamp recordings were performed on either transverse or parasagittal spinal cord slices. Recording made in transverse spinal cord slices showed that an inward current (I T) was observed in 44.5% of the SG neurons that was fully blocked by Ni2+ and TTA-A2. The amplitude of I T depended on the magnitude and the duration of hyperpolarization pre-pulse. The voltage for eliciting and maximizing I T were -70 mV and -35 mV, respectively. In addition, we found that most of the I T-expressing neurons are tonic firing neurons and exhibit more negative action potential (AP) threshold and smaller difference of AP threshold and resting membrane potential (RMP) than those neurons lacking I T. Consistently, a specific T-type calcium channel blocker TTA-P2 increased the AP threshold and enlarged the difference between AP threshold and membrane potential (Ihold = 0). Meanwhile, the morphological analysis indicated that most of the I T-expressing neurons are islet neurons. In conclusion, we identify a cell-type specific distribution and the function of T-type channels in SG neurons. These findings might provide new insights into the mechanisms underlying the contribution of T-type channels in sensory transmission.

12.
Anesth Analg ; 122(4): 1048-59, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26756913

RESUMO

BACKGROUND: Lidocaine, which blocks voltage-gated sodium channels, is widely used in surgical anesthesia and pain management. Recently, it has been proposed that the hyperpolarization-activated cyclic nucleotide (HCN) channel is one of the other novel targets of lidocaine. Substantia gelatinosa in the spinal dorsal horn, which plays key roles in modulating nociceptive information from primary afferents, comprises heterogeneous interneurons that can be electrophysiologically categorized by firing pattern. Our previous study demonstrated that a substantial proportion of substantia gelatinosa neurons reveal the presence of HCN current (Ih); however, the roles of lidocaine and HCN channel expression in different types of substantia gelatinosa neurons remain unclear. METHODS: By using the whole-cell patch-clamp technique, we investigated the effect of lidocaine on Ih in rat substantia gelatinosa neurons of acute dissociated spinal cord slices. RESULTS: We found that lidocaine rapidly decreased the peak Ih amplitude with an IC50 of 80 µM. The inhibition rate on Ih was not significantly different with a second application of lidocaine in the same neuron. Tetrodotoxin, a sodium channel blocker, did not affect lidocaine's effect on Ih. In addition, lidocaine shifted the half-activation potential of Ih from -109.7 to -114.9 mV and slowed activation. Moreover, the reversal potential of Ih was shifted by -7.5 mV by lidocaine. In the current clamp, lidocaine decreased the resting membrane potential, increased membrane resistance, delayed rebound depolarization latency, and reduced the rebound spike frequency. We further found that approximately 58% of substantia gelatinosa neurons examined expressed Ih, in which most of them were tonically firing. CONCLUSIONS: Our studies demonstrate that lidocaine strongly inhibits Ih in a reversible and concentration-dependent manner in substantia gelatinosa neurons, independent of tetrodotoxin-sensitive sodium channels. Thus, our study provides new insight into the mechanism underlying the central analgesic effect of the systemic administration of lidocaine.


Assuntos
Anestésicos Locais/farmacologia , Canais Disparados por Nucleotídeos Cíclicos Ativados por Hiperpolarização/antagonistas & inibidores , Lidocaína/farmacologia , Neurônios/efeitos dos fármacos , Substância Gelatinosa/efeitos dos fármacos , Animais , Células Cultivadas , Canais Disparados por Nucleotídeos Cíclicos Ativados por Hiperpolarização/fisiologia , Masculino , Neurônios/fisiologia , Ratos , Ratos Sprague-Dawley , Substância Gelatinosa/fisiologia
14.
Nan Fang Yi Ke Da Xue Xue Bao ; 37(2): 204-209, 2016 Feb 20.
Artigo em Chinês | MEDLINE | ID: mdl-28219864

RESUMO

OBJECTIVE: To investigate the rebound depolarization of substantia gelatinosa (SG) neurons in rat spinal dorsal horn and explore its modulatory mechanisms to provide better insights into rebound depolarization-related diseases. METHODS: Parasagittal slices of the spinal cord were prepared from 3- to 5-week-old Sprague-Dawley rats. The electrophysiologic characteristics and responses to hyperpolarization stimulation were recorded using whole-cell patch-clamp technique. The effects of hyperpolarization-activated cyclic nucleotide gated cation (HCN) channel blockers and T-type calcium channel blockers on rebound depolarization of the neurons were studied. RESULTS: A total of 63 SG neurons were recorded. Among them, 23 neurons showed no rebound depolarization, 19 neurons showed rebound depolarization without spikes, and 21 neurons showed rebound depolarization with spikes. The action potential thresholds of the neurons without rebound depolarization were significantly higher than those of the neurons with rebound depolarization and spikes (-28.7∓1.6 mV vs -36.0∓2.0 mV, P<0.05). The two HCN channel blockers CsCl and ZD7288 significantly delayed the latency of rebound depolarization with spike from 45.9∓11.6 ms to 121.6∓51.3 ms (P<0.05) and from 36.2∓10.3 ms to 73.6∓13.6 ms (P<0.05), respectively. ZD7288 also significantly prolonged the latency of rebound depolarization without spike from 71.9∓35.1 ms to 267.0∓68.8 ms (P<0.05). The T-type calcium channel blockers NiCl2 and mibefradil strongly decreased the amplitude of rebound depolarization with spike from 19.9∓6.3 mV to 9.5∓4.5 mV (P<0.05) and from 26.1∓9.4 mV to 15.5∓5.0 mV (P<0.05), respectively. Mibefradil also significantly decreased the amplitude of rebound depolarization without spike from 14.3∓3.0 mV to 7.9∓2.0 mV (P<0.05). CONCLUSION: Nearly two-thirds of the SG neurons have rebound depolarizations modulated by HCN channel and T-type calcium channel.


Assuntos
Neurônios/citologia , Corno Dorsal da Medula Espinal/citologia , Substância Gelatinosa/citologia , Potenciais de Ação , Animais , Bloqueadores dos Canais de Cálcio/farmacologia , Canais de Cálcio Tipo T , Polaridade Celular , Césio/farmacologia , Cloretos/farmacologia , Canais de Cátion Regulados por Nucleotídeos Cíclicos/antagonistas & inibidores , Técnicas de Patch-Clamp , Pirimidinas/farmacologia , Ratos , Ratos Sprague-Dawley
15.
Nan Fang Yi Ke Da Xue Xue Bao ; 35(8): 1155-61, 2015 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-26277513

RESUMO

OBJECTIVE: To investigate the effect of minocycline on hyperpolarization-activated current (Ih) in the substantia gelatinosa (SG) neurons in rat spinal dorsal horn. METHODS: In vitro spinal cord transverse slices were prepared from 3-5-week-old male Sprague-Dawley rats. Using whole-cell patch clamp technique, Ih currents were recorded before and after bath application of minocycline (1-300 µmol/L) to the SG neurons. RESULTS: Ih currents were observed in nearly 50% of the recorded neurons, and were blocked by Ih blocker CsCl and ZD7288. Minocycline rapidly and reversibly reduced the amplitude of Ih and decreased the current density in a concentration-dependent manner with an IC50 of 34 µmol/L. CONCLUSION: Minocycline suppresses the excitability of SG neurons through inhibiting the amplitude and current density of Ih and thereby contributes to pain modulation.


Assuntos
Minociclina/farmacologia , Neurônios/efeitos dos fármacos , Substância Gelatinosa/citologia , Animais , Masculino , Técnicas de Patch-Clamp , Ratos , Ratos Sprague-Dawley
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...