MASH1 induces neuron transdifferentiation of adrenal medulla chromaffin cells / 中南大学学报(医学版)

OBJECTIVES@#Nerve growth factor (NGF) induces neuron transdifferentiation of adrenal medulla chromaffin cells (AMCCs) and consequently downregulates the secretion of epinephrine (EPI), which may be involved in the pathogenesis of bronchial asthma. Mammalian achaete scute-homologous 1 (MASH1), a key regulator of neurogenesis in the nervous system, has been proved to be elevated in AMCCs with neuron transdifferentiation in vivo. This study aims to explore the role of MASH1 in the process of neuron transdifferentiation of AMCCs and the mechanisms.@*METHODS@#Rat AMCCs were isolated and cultured. AMCCs were transfected with siMASH1 or MASH1 overexpression plasmid, then were stimulated with NGF and/or dexamethasone, PD98059 (a MAPK kinase-1 inhibitor) for 48 hours. Morphological changes were observed using light and electron microscope. Phenylethanolamine-N-methyltransferase (PNMT, the key enzyme for epinephrine synthesis) and tyrosine hydroxylase were detected by immunofluorescence. Western blotting was used to test the protein levels of PNMT, MASH1, peripherin (neuronal markers), extracellular regulated protein kinases (ERK), phosphorylated extracellular regulated protein kinases (pERK), and JMJD3. Real-time RT-PCR was applied to analyze the mRNA levels of MASH1 and JMJD3. EPI levels in the cellular supernatant were measured using ELISA.@*RESULTS@#Cells with both tyrosine hydroxylase and PNMT positive by immunofluorescence were proved to be AMCCs. Exposure to NGF, AMCCs exhibited neurite-like processes concomitant with increases in pERK/ERK, peripherin, and MASH1 levels (all P<0.05). Additionally, impairment of endocrine phenotype was proved by a signifcant decrease in the PNMT level and the secretion of EPI from AMCCs (all P<0.01). MASH1 interference reversed the effect of NGF, causing increases in the levels of PNMT and EPI, conversely reduced the peripherin level and cell processes (all P<0.01). MASH1 overexpression significantly increased the number of cell processes and peripherin level, while decreased the levels of PNMT and EPI (all P<0.01). Compared with the NGF group, the levels of MASH1, JMJD3 protein and mRNA in AMCCs in the NGF+PD98059 group were decreased (all P<0.05). After treatment with PD98059 and dexamethasone, the effect of NGF on promoting the transdifferentiation of AMCCs was inhibited, and the number of cell processes and EPI levels were decreased (both P<0.05). In addition, the activity of the pERK/MASH1 pathway activated by NGF was also inhibited.@*CONCLUSIONS@#MASH1 is the key factor in neuron transdifferentiation of AMCCs. NGF-induced neuron transdifferentiation is probably mediated via pERK/MASH1 signaling.

Feocromocitoma maligno de presentación retroperitoneal / Retroperitoneal Malignant Pheochromocytoma

RESUMEN Introducción: la neoplasia más común y mejor conocida de la médula adrenal es el feocromocitoma benigno, que puede definirse como un paraganglioma de la médula suprarrenal, el cual puede secretar catecolaminas del tipo, norepinefrina, epinefrina o ambas. Presentación de caso: paciente femenina de 36 años, de raza blanca, con antecedentes de salud, valorada por dolor lumbar no irradiado, que se aliviaba espontáneamente, con cifras tensionales al ingreso de 170/100 mm de Hg, la ecografía informa la presencia de tumor retroperitoneal, se realiza exéresis quirúrgica del tumor, durante el transoperatorio la paciente sufre inestabilidad hemodinámica, con hipotensión, taquicardia y parada cardiorrespiratoria, que logra recuperarse. La paciente fallece en las primeras seis horas del postoperatorio en un cuadro de shock. Conclusiones: el feocromocitoma maligno constituye solo el 10 % de estas neoplasias, siendo una tumoración infrecuente en nuestro medio, motivo por el cual se consideró pertinente su presentación. El diagnóstico se realizó por estudio histológico, planteándose el feocromocitoma maligno. Se presentó un caso clínico de feocromocitoma maligno suprarrenal, pretendiendo con ello aportar un mayor conocimiento de esta neoplasia.

ABSTRACT Introduction: the most common and best-known neoplasm of the adrenal medulla is benign pheochromocytoma, which can be defined as a paraganglioma of the adrenal medulla, which may secrete catecholamine of the types of norepinephrine, epinephrine, or both. Clinical case: a 36-year-old, white race, female patient with a health history, assessed for a non-irradiated lumbar pain, which was spontaneously relieved, a blood pressure of 170/100 mm Hg at admission, the ultrasound reported the presence of a retroperitoneal tumor, the surgical exeresis of the tumor was performed, during the trans-operative stage the patient suffered from hemodynamic instability, hypotension, tachycardia and cardio-respiratory arrest, which was managed to her recovery. The patient dies in the first 6 hours as a consequence of a postoperative shock. Conclusions: malignant pheochromocytoma constitutes only 10 % of these types of neoplasm, being an infrequent tumor in our environment; its report was significant to be presented. The diagnosis was made by histological study, considering malignant pheochromocytoma. A clinical case of adrenal malignant pheochromocytoma was reported, with the intention of contributing to the acquisition of a better management in relation to this type of neoplasm.

Effect of propofol on secretory function of adrenal medullary chromaffin cells of rats / 中华麻醉学杂志

Objective To investigate the effect of propofol on the secretory function of adrenal medullary chromaffin cells of rats.Methods The rat adrenal pheochromocytoma cells cultured in vitro were seeded in 24-well plates at a density of 1×1010 cells/ml and divided into 5 groups (n=12 each) using a random number table:control group (group C),different concentrations of propofol groups (P1 and P2 groups),and different concentrations of etomidate groups (E1 and E2 groups).Propofol was added with the final concentrations of 30 and 100 μmol/L in P1 and P2 groups,respectively.Etomidate was added with the final concentrations of 4 and 40 μmol/L in EI and E2 groups,respectively.The cells were then incubated for 10 min in an incubator at 37 ℃.At the end of incubation with drugs,6 wells in each group were selected,and physiological salt solution 200 μl was added;another 6 wells in each group were selected,and high K+ physiological salt solution was added.[3 H] PSS and [3 H] K+-PSS were measured by [3 H] norepinephrine release assays.Results Compared with group C,[3 H] K+-PSS and [3 H] K+-PSS/PSS were significantly decreased in P1,P2 and E2 groups (P＜0.05),and no significant changes were found in [3H] K+-PSS and [3H] K+-PSS/PSS in group E1 (P＞0.05).Compared with group P1,[3 H] K+-PSS and [3 H] K+-PSS/ PSS were significantly decreased in group P2 (P＜0.05).Conclusion Propofol can inhibit the secretory function of adrenal medullary chromaffin cells of rats in a concentration-dependent manner.

Augmentation of catecholamine release elicited by an Eugenia punicifolia extract in chromaffin cells

Plant extracts of Eugenia punicifolia (Kunth) DC., Myrtaceae, are used in Amazon region of Brazil to treat diarrhea and stomach disturbances, and as hypoglycemic medicine. We have recently shown that an aqueous extract of E. punicifolia augmented cholinergic neurotransmission in a rat phrenic nerve-diaphragm preparation. In this study, we investigated the effects of an E. punicifolia dichloromethane extract (EPEX) in a neuronal model of cholinergic neurotransmission, the bovine adrenal chromaffin cell. EPEX augmented the release of catecholamine triggered by acetylcholine (ACh) pulses but did not enhance ACh-evoked inward currents, which were inhibited by 30 percent. Since EPEX did not cause a blockade of acetylcholinesterase or butyrylcholinesterase, it seems that EPEX is not directly activating the cholinergic system. EPEX also augmented K+-elicited secretion without enhancing the whole-cell inward calcium current. This novel and potent effect of EPEX in enhancing exocytosis might help to identify the active component responsible for augmenting exocytosis. When elucidated, the molecular structure of this active principle could serve as a template to synthesise novel compounds to regulate the exocytotic release of neurotransmitters.

Cultured human chromaffin cells grafted in spinal subarachnoid space relieves allodynia in a pain rat model / 대한마취과학회지

BACKGROUND: Implantation of xenogenic chromaffin cells into the spinal subarachnoid space can produce analgesia in neuropathic pain models. However, transplantation of xenogeneic chromaffin cell has a potential risk of viral or bacterial infections from animals to humans including encephalopathy due to prion transmission. The aim of this study was to investigate the possibility of developing a homogeneic source of therapeutic chromaffin cells. METHODS: Anti-allodynic effects of human chromaffin cells (HCCs) were evaluated in a neuropathic pain model in rats induced by chronic constriction injury of the sciatic nerve. HCCs encapsulated with alginate-poly-L-lysine-alginate were intrathecally implanted into rats (n = 10), while empty capsules were intrathecally implanted as a control (n = 8). Levels of norepinephrine from encapsulated HCCs before and after nicotinic stimulation were measured. We then perfomed a behavior test (cold allodynia) with acetone. In addition, to assess the potential contribution to pain reduction of opioid peptides released from the HCCs, all animals were injected with naloxone. RESULTS: The concentration of norepinephrine after nicotine stimulation was significantly increased compared to basal levels. Intrathecal implantation of encapsulated HCCs, significantly reduced cold allodynia as compared to rats receiving empty capsules (P < 0.05). Fifteen minutes after the injection of naloxone, cold allodynia significantly decreased in rats with HCCs (P < 0.05), while the degree of cold allodynia in control animals was unaltered. CONCLUSIONS: From these results, it appears that HCCs have a possibility as an analgesic source for transplants delivering pain-reducing neuroactive substances.

Microencapsulated Bovine Adrenal Medullary Chromaffin Cells Transplanted into Rat Spinal Cord Alleviated Cold Allodynia / 대한마취과학회지

BACKGROUND: The intrathecal grafting of adrenal chromaffin cells as a potential analgesic source, to delivery analgesic substances such as catecholamines and opioid peptides, is known to be effective at treating acute and chronic pain in several animal pain models. We tested whether the intrathecal implantation of encapsulated bovine chromaffin cells reduces cold allodynia in a rat model of neuropathic pain induced by chronic constriction injury of the sciatic nerve. METHODS: Bovine adrenal medullary chromaffin cells microencapsulated in sodium alginate-poly-l-lysin-alginate (APA) were implanted into the subarachnoid space of rats (n = 10) and foot cold sensitivity was investigated using an acetone test. At the end of the study, histology and capsule catecholamine production were evaluated. RESULTS: A significant reduction in cold allodynia was observed in animals implanted with chromaffin cells. In addition, the suppression of cold allodynia was reversed by naloxone. Abundant clusters of viable chromaffin cells stained with neutral red, were observed in the retrieved implants and after nicotine stimulation, and catecholamine was quantified. An ultrastructural study showed no fibrotic reaction against capsules, or disorganised capsules. CONCLUSIONS: These results suggest that intrathecal encapsulated chromaffin cells act as "mini pumps", which continuously deliver analgesic substances and produce analgesia in this chronic pain model of nerve injury-without immunosuppressant.

Do Microencapsulated Bovine Adrenal Medullary Chromaffin Cells Transplanted in Rats' Spinal Cord Produce Analgesic Effects? / 대한마취과학회지

BACKGROUND: Pain remains the chief complaint that brings patients to physician's office, despite recent insights into underlying mechanism and the identification of potential new therapeutic targets. In recent years, however, with the development of molecular biology cell transplantation gives us a new chance for treating intractable chronic pain. The major purpose of the present study was to determine if the chromaffin cells that were encapsulated with 1.3% (w/v) sodium alginate-poly-l-lysine-alginate (APA) had robust analgesic effects in the spinal atlanto-occipital subarachnoid space even without nicotine stimulation. METHODS: In order to determine whether microencapsulated bovine adrenal medullary chromaffin cells transplanted in the spinal cord can produce analgesic effects, we microencapsulated adrenal medullary chromaffin cells with APA and implanted them into the subarachnoid space of rats' (n = 10) spinal cord, and investigated the hot sensitivity of rats' hind-paw by a light-beam test. RESULTS: It was found that compared with the control group, hot response latency of the group which received adrenal medullary chromaffin cells increased from the 12th day and the analgesic efficacy was maintained for at least 75 days. CONCLUSIONS: Microencapsulated bovine adrenal medullary chromaffin cells transplanted in the rats' spinal cord may provide a permanent and locally available source of neuropeptides for the relief of intractable pain. Furthermore, these kinds of analgesic effect were produced without any stimulation such as nicotine.

The Regulation of AP-1 DNA Binding Activity by Long-term Nicotine Stimulation in Bovine Adrenal Medullary Chromaffin Cells: Role of Second Messengers

The signal pathways involved in the regulation of AP-1 DNA binding activity in long-term nicotine stimulated bovine adrenal medullary chromaffin (BAMC) cells have not been well characterized. To understand the involvement of second messengers in the regulation of AP-1 DNA binding activity, the present study was designed to define the time-course for inhibition of nicotine-induced responses by cholinergic antagonists, Ca2+ and calmodulin (CaM) antagonists, and calcium/calmodulin-dependent protein kinase (CaMK) II inhibitor using electrophoretic mobility shift assay. Nicotine (10microM) stimulation increased AP-1 DNA binding activity at 24 hr after treatment. Posttreatment with hexamethonium (1 mM) plus atropine (1microM) (HA), nimodipine (1microM), or calmidazolium (1microM) at 0.5, 3, and 6 hr after the nicotine treatment significantly inhibited the AP-1 DNA binding activity increased by long-term nicotine stimulation. However, posttreatment with HA, nimodipine, or calmidazolium at 9 or 12 hr after the nicotine treatment did not affect the nicotine-induced increase of AP-1 DNA binding activity. The pretreatment of BAMC cells with various concentrations of KN-62 inhibited the increase of AP-1 DNA binding activity induced by nicotine in a concentration-dependent manner. KN-62 (10microM) posttreatment beginning at 0.5, 3, or 6 hr after the nicotine treatment significantly inhibited the increase of AP-1 DNA binding activity. However, KN-62 posttreatment beginning at 9 or 12 hr after the nicotine treatment did not affect the increase of AP-1 DNA binding activity. This study suggested that stimulation (for at least 6 hr) of nicotinic receptors on BAMC cells was necessary for increase of AP-1 DNA binding activity, and activation of Ca2+, CaM, and CaMK II up to 6 hr at least seemed to be required for the increase of nicotine-induced AP-1 DNA binding activity.

Dysfunction of releasing adrenaline in primary cultured AMCC due to functional reduncdency primed by nerve growth factor / 中国实用内科杂志

Objective To investigate the possible mechanism of the biologic ethology effects of NGF and SP(substance P)on primary cultured adrenaline medullary chromaffin cells(AMCC).Methods To establish primary cultured AMCC by means of enzyme digestion and purify the cells by means of isopycnic gradient centrifugation and differential plating.To observe the morphological and ultrastructural changes after the addition of NGF and SP,and detect the concentration of adrenaline and noradrenaline in serum by ELISA.Results Confervaceous processes could be observed after 2 d of addition of NGF to the culture and the processes strenched longer as days went by the observation of electron microscopy.there are some drumstick-like and villiform processes in the cell membrane and some vesiculation be observed near the cell membrane of the primary cultured AMCC cells after the addition of NGF.The bioblast was abundant but the structure was not clear in the intracytoplasm and the concentration of adrenaline were decreased(P

Analgesic Effect of Transplanted Adrenal Medullary Chromaffin Cells in Rats Spinal Cord / 대한마취과학회지

BACKGROUND: Despite of numerous researches on the mechanisms and new therapeutic methods of chronic pain, patients are still suffering even with the help of opioids. In recent years, however, with the development of molecular-biology cell transplantation gives us a new chance for treating intractable chronic pain. The major purpose of the present study was to determine if the chromaffin cells have robust analgesic effects in the spinal atlanto-occipital subarachnoid space even without nicotine stimulation. METHODS: In order to determine whether cultured bovine adrenal medullary chromaffin cells transplanted in the spinal cord can produce analgesic effects, we purified adrenal medullary chromaffin cells and implanted them into the subarachnoid space of rats' (n = 10) spinal cord without immunosuppression, and investigated the hot sensitivity of rats' hind-paw by a light-beam test. RESULTS: It was found that compared with the control group, hot response latency of the group which received adrenal medullary chromaffin cells had increased at 14 days and the analgesic efficacy was maintained for at least 3 months. CONCLUSIONS: Adrenal medullary chromaffin cells transplanted in the rats' spinal cord may provide a permanent and locally available source of neuropeptides for the relief of intractable pain. Furthermore, these kinds of analgesic effect even produced without any stimulation such as nicotine.

Effects of calcium channel blockers on nicotinic acetylcholine receptor current in rat chromaffin cells / 中国病理生理杂志

AIM: To study the effects of calcium channel blockers (CCB) on nicotinic acetylcholine receptor current (I_(NIC)) in rat adrenal medullar chromaffin cells (RAMCs). METHODS: By using the whole-cell clamp-patch technique, we have investigated the effects of nifedipine(NIF)、?-conotoxin GVIA and ?-agatoxin IVA on I_(NIC) induced by nicotine(NIC) before and after RAMCs perfusion. RESULTS: After perfusing RAMCs for 5 min, different kinds of calcium channel blockers at different concentration showed significant inhibitory effects on I_(NIC) induced by 50 ?mol/L NIC. The peak inhibition rates of 10 ?mol/L NIF、400 nmol/L ?-conotoxin GVIA and 100 nmol/L ?-agatoxin IVA were (61.7?5.1)%,(29.3?7.4)% and (17.6?7.5)%, respectively. CONCLUSION: The acute effects of different kinds of CCBs on RAMC were that they obviously inhibited I_(NIC) induced by NIC. These results suggest that CCBs may inhibit catecholamine secretion by directly blocking nicotinic acetylcholine receptor channel. [

The secretion of catecholamine in cultured rat adrenal medullary chromaffin cells measured by high-performance liquid chromatography-electrochemical detection assay / 中国药学杂志

OBJECTIVE：To study the secretion of catecholamine primary cultures of chromaffin cells from rat adrenal medulla were used.METHOD:Catechoalmines(norepinephrine,epinephrine and dopamine) were measured by high-performance liquid chromatography-electrochemical detection technique.RESULTS:Catecholamine released by chromaffin cells with in 20min without slimalus was (73.29±15.32) ng/106 cells.When acetylcholine,nicotine or muscarine was added,the secretion of catecholamine was then increased.CONCLUSION:Using high-performance liquid chromatography-electrochemical detection technique,we can detect sensitively catecholamine released by cultured rat chromaffin cells.

Influence of glucocorticoids on cholinergic stimulation-induced catecholamine secretion from the rat adrenal medulla

The present study was undertaken to examine the influence of glucocorticoids on the secretory responses of catecholamines (CA) evoked by acetylcholine (ACh), DMPP, McN-A-343, excess K+ and Bay-K-8644 from the isolated perfused rat adrenal gland and to clarify the mechanism of its action. The perfusion of the synthetic glucocorticoid dexamethasone (10-100 micrometer) into an adrenal vein for 20 min produced a dose-dependent inhibition in CA secretion evoked by ACh (5.32 mM), excess K+ (a membrane-depolarizor 56 mM), DMPP (a selective nicotinic receptor agonist, 100 micrometer for 2 min), McN-A-343 (a muscarinic receptor agonist, 100 micrometer for 4 min), Bay-K-8644 (a calcium channel activator, 10 micrometer for 4 min) and cyclopiazonic acid (a releaser of intracellular Ca2+ 10 micrometer for 4 min). Similarly, the preperfusion of hydrocortisone (30 micrometer) for 20 min also attenuated significantly the secretory responses of CA evoked by nicotinic and muscarinic receptor stimulation as well as membrane-depolarization, Ca2+ channel activation and the release of intracellular Ca2+. Furthermore, even in the presence of betamethasone (30micrometer), CA secretion evoked by ACh, excess K+, DMPP and McN-A-343 was also markedly inhibited. Taken together, the present results suggest that glucocorticoids cause the marked inhibition of CA secretion evoked by both cholinergic nicotinic and muscarinic receptor stimulation from the isolated perfused rat adrenal gland, indicating strongly that this inhibitory effect may be mediated by inhibiting influx of extracellular calcium as well as the release of intracellular calcium in the rat adrenomedullary chromaffin cells.

Study on microencapsulated human chromaffin cells cultured in vitro / 中华麻醉学杂志

Objective To compare the catecholamine (CA ) and M enkephalin(M ENK) release from human chromaffin cells (HCC) and microencapsulated HCC (ME HCC ) and investigate the effects of microencapsulation on the growth and activity of chromaffin cells Methods Adrenal glands were taken from brain death healthy adults The chromaffin cells were isolated and primarily cultured in vitro During culture the chromaffin cells were HE stained and assessed by labelling the cells with tyrosine hydroxylase monoclonal antibody The percentage of tyrosine positive cells were counted under microscope (1) The chromaffin cells were microencapsulated with 2% alginate and cultured in vitro (experimental group) HCC which were not microencapsulated were used as control The culture media of both groups were replaced every 48h and collected and stored under -20℃ for determination of CA and M ENK concentration (2) On the 6th day of culture, nicotine was added to HCC and MC HCC suspension After 30 min incubation, the suspension was centrifuged and the supernate collected and stored under -20 ℃ for determinatoin of CA and M ENK concentration with radioimmunoassay Results (1) ME HCC grew fairly well in vitro in the culture medium and was morphologically similar to HCC (2) There was no significant difference in CA and M ENK concentration in HCC and ME HCC culture media (3) CA and M ENK concentrations in supernate were increased by nicotine stimulation and there was no difference in the CA and M ENK concentration in the supernate between the two groups Conclusions Alginate and microencapsulation technique are not harmful to HCC, ME HCC has fairly good activity and release function and can be effectively used for transplantation

Effects of subarachnoid implantation of micro-capsulized bovine chromaffin cells on expression of mRNA for GABAA receptor in spinal cord in rats with neuropathic pain / 中华麻醉学杂志

Objective To study the effects of subsrachnoid implantation of APA microcapsules-filled with bovine chromaffin cells (BCCs) on expression of mRNA for ?2 and ?2 subunits of GABAA receptor in spinal cord in rats with chronic constrictive injury (CCI) of sciatic nerve and to determine if GABAA receptor is involved in the mechanisms of analgesia produced by subarachnoid implantation of micro-capsulized BCCs. Methods Twenty SD rats weighing 200-250 g were randomly divided into 4 groups with 5 animals in each group : (Ⅰ) control group (group C); (Ⅱ) CCI group in which right sciatic nerve was loosely ligated; (Ⅲ) APA group in which 500-600 empty APA micro-capsules were implanted in subarachnoid space and (Ⅳ) APA-BCC group in which 5?106 APA micro-capsules filled with BCCs were implanted in subarachnoid space. In group Ⅲ and Ⅳ subarachnoid implantation was performed at L1-3 level 7 days after CCI operation. Pain threshold to mechanical stimulation with Von-Frey filament and thermal stimulation with CO2 laser was measured before and 7 days after implantation. Expression of mRNA for GABAA receptor ?2 and ?2 subunit in spinal cord was measured by RT-PCR.Results The expression of mRNA for GABAA receptor ?2 and ?2 subunit in spinal cord was significantly lower in CCI and APA groups (group Ⅱ and Ⅲ) than that in control group (group Ⅰ). In APA-BCC group (group Ⅳ) pain threshold of surgical side to mechanical and thermal stimuli and the expression of mRNA for GABAA receptor ?2 and ?2 subunit in spinal cord were significantly higher than those in group Ⅱ and Ⅲ . Conclusion The expression of mRNA for GABAA receptor?2 and ?2 subunit in spinal cord is down-regulated by CCI and subarachnoid implantation of micro-capsulized BCCs can reverse the down-regulation. Recovery of GABAA-nergic neuron activity contributes to the analgesic effect of aubarachnoid implantation of micro-capsalized BCCs.

Feasibility of subarachnoid chromaffin cell allograft for terminal cancer pain / 中华麻醉学杂志

Objective To evaluate the analgesic effect and safety of subarachnoid chromaffin cell allograft for terminal cancer pain Methods Ten patients with intractable cancer pain despite traditional treatments were randomly divided into two groups In test group(n=4), 2ml of the suspension chromaffin cells cultured in vitro for 3 days was injected into the subarachnoid space through lumber puncture The same amount of cell free culture solution was injected intrathecally in control group(n=6) Opioids were administered continuously after transplantation The intensity of pain was assessed by VAS, the dose of opioids taken was recored,and the catecholamine and enkephalin concentrations in cerebrospinal fluid and immune function were measured before and after transplantation Results The VAS scores declined markedly in both groups after transplantation (P

Immunoisolation effect of xenografts of microencapsulated human chromaffin cells in rats / 中华麻醉学杂志

Objective To investigate the immunoisolation effect of xenografts of microencapsulated human chromaffin cells (HCCs) .Methods HCCs were microencapsulated with APA microcapsules. Forty-eight SD rats were randomly divided into 3 groups ( n = 16 each) . HCCs (group I ) , empty APA microcapsules (group II ) and microencapsulated HCCs (group III ) were implanted into the anterior chamber of the eyes and the sole of the feet. Seven days after transplantation blood samples were collected for determination of serum IL-2, IgG and IgM concentration. The right eye-balls and left feet were obtained for microscopic examination. Results The serum IL-2, IgG and IgM concentrations were significantly lower in group II and group III than in group I ( P

Acute action of glucocorticoid on catecholamine secretion of adrenal chromaffin cells in rats / 中华内分泌代谢杂志

By using the whole-cell clamp-patch technique, the effects of dexamethasone on calcium channel current (Ica) and nicotine receptor channel current (I_(NIC)) were examined. The acute action of glucocorticoid on adrenal medullary chromaffin cell (AMCC) of rats was a significant inhibition of I_(NIC), while no apparent effect was observed on Ica induced by electricity. The results suggest that the acute action of glucocorticoid on catecholamine release in rat AMCC may be directly related to nicotine receptor.