Effects of sevoflurane combined with propofol anesthesia on synaptic plasticity in hippocampus after operation in rats with mild cognitive impairment: relationship with KCC2/NKCC1 / 中华麻醉学杂志

Objective:To evaluate the effects of sevoflurane combined with propofol anesthesia on the synaptic plasticity in the hippocampus after operation in rats with mild cognitive impairment (MCI) and the relationship with potassium-chloride cotransporter-2 (KCC2)/sodium-potassium-chloride cotransporter 1 (NKCC1).Methods:Clean-grade healthy male Sprague-Dawley rats, aged 16-18 months, weighing 440-540 g, in which MCI was induced by severe bilateral common carotid artery stenosis (BCAS). Forty-eight rats with MCI were divided into 4 groups ( n=12 each) using a random number table method: sham operation group (group Sham), sevoflurane anesthesia group (group S), propofol anesthesia group (group P), and sevoflurane and propofol anesthesia group (group SP). After disappearance of eyelash reflex, open reduction and internal fixation was performed after tibial fracture was induced in S, P and SP groups.Anesthesia method was as follows: 1.7% sevoflurane was inhaled and propofol 20 mg·kg -1·h -1 was intravenously infused for 3 h in group SP, 3% sevoflurane was inhaled for 3 h in group S, and propofol was intravenously infused at rate of 40 mg·kg -1·h -1 for 3 h in group P. The novel object recognition (NOR) test was performed at 14 days after operation, and the discrimination index in NOR test was calculated.The in vivo electrophysiological experiment was performed on 19 days after operation to measure long-term potentiation and amplitude of the field excitatory postsynaptic potential (fEPSP). The expression of KCC2 and NKCC1 was determined by Western blot, and the ratio of KCC2/NKCC1 was calculated.The density of dendritic spines in the hippocampal CA1 region was determined by Golgi-COX staining performed at 30 days after operation. Results:Compared with Sham group, the discrimination index in NOR test, hippocampal KCC2/NKCC1 ratio, density of dendritic spines in hippocampal CA1 region, and amplitude of fEPSP were significantly decreased in S and P groups ( P<0.05), and no significant change was found in the parameters mentioned above in group SP ( P>0.05). Compared with group S or group P, the discrimination index in NOR test, hippocampal KCC2/NKCC1 ratio, density of dendritic spines in hippocampal CA1 region, and amplitude of fEPSP were significantly increased in group SP ( P<0.05). Conclusion:Sevoflurane combined with propofol anesthesia does not aggravate postoperative cognitive dysfunction in the rats with MCI, which may be related to maintaining the balance of hippocampal KCC2/NKCC1 and protecting the synaptic plasticity in hippocampi.

Relationship between dexmedetomidine-induced reduction of sevoflurane-induced neurotoxicity and NKCC1/KCC2 in neonatal rats / 中华麻醉学杂志

Objective:To evaluate the relationship between dexmedetomidine-induced reduction of sevoflurane-induced neurotoxicity and cation-chloride cotransporters Na + -K + -2Cl --1 (NKCC1) /K + -2Cl --2 (KCC2) in neonatal rats. Methods:Eighty healthy male Sprague-Dawley rats at postnatal day 7 were divided into 4 groups ( n=20 each) using a random number table method: control group (group C), sevoflurane anesthesia group (group S), dexmedetomidine group (group D), and sevoflurane and dexmedetomidine group (group SD). Rats were exposed to 2.5% sevoflurane for 6 h to establish the model of sevoflurane anesthesia in group S. Dexmedetomidine 1.0 μg/kg was intraperitoneally injected, and then sevoflurane anesthesia was performed in group SD.The expression of cleaved caspase-3, NKCC1 and KCC2 was detected by Western blot at 24 h after the end of anesthesia.At 35 days after the end of anesthesia, the cognitive function was assessed using the Y maze test, and the neurons in the hippocampal CA1 area were counted using the Nissan staining method. Results:Compared with group C, the percentage of time spent in novel arm and the number of neurons in hippocampal CA1 area were significantly decreased, the expression of cleaved caspase-3 and NKCC1 was up-regulated, the expression of KCC2 was down-regulated, and the ratio of NKCC1/KCC2 was increased in S and SD groups ( P<0.05), and no change was found in the above indicators in group D ( P>0.05). Compared with group S, the percentage of time spent in novel arm and the number of neurons in hippocampal CA1 area were significantly increased, the expression of cleaved caspase-3 and NKCC1 was down-regulated, the expression of KCC2 was up-regulated, and the ratio of NKCC1/KCC2 was decreased in group SD ( P<0.05). Conclusion:The mechanism of dexmedetomidine attenuating sevoflurane-induced neurotoxicity may be related to maintaining the relatively stable expression of NKCC1/KCC2 in neonatal rats.

Correlation between urinary iodine and clinical characteristics in breast cancer / 中国医师杂志

Objective To explore the relationship between urinary iodine level and breast cancer,we compare urinary iodine excretion levels in patients with breast cancer,benign breast disease,other female malignant tumors and control subjects in Xiangya Hospital of Central South University.Methods From December 2018 to January 2019,64 patients with newly diagnosed breast cancer in Xiangya Hospital of Central South University were selected as case group,benign breast disease group (n =49),other female malignant tumor group (n =39) and health examination group (n =50) as control group.Urinary iodine was determined by colorimetry.According to the urinary iodine level the patients divided into three groups:iodine excess (＞300 μg/L),medium iodine (100-300 μg/L) and iodine deficiency (＜ 100 μg/L).The relationship between urinary iodine and clinicopathology of breast cancer was analyzed.Results The level of urinary iodine in benign breast nodule group 319.13 (163.98) μg/L ＞ breast cancer group 273.96 (151.30) μg/L ＞ female other malignant tumor group 212.95 (161.71) μg/L ＞ normal control group 199.15 (194.45) μg/L,with significantly differance (H =9.936,P =0.019).Urinary iodine level in the normal control group was significantly lower than that in the benign breast disease group (P =0.013).The patients were further divided into three groups according to the urinary iodine level:iodine excess,iodine medium and iodine deficiency,the number of urine iodine ＜ 100 μg/L in the normal control group was significantly higher than that in the breast cancer group (P =0.021).The level of urinary iodine was negatively correlated with the size of the primary focus of breast cancer (Z =-2.307,P =0.021).The effect of urinary iodine was analyzed by multiple linear regression method.The size of primary focus was included in the regression equation (R2 =0.136,P=0.007),but had nothing to do with lymph node metastasis and the expression status of estrogen receptor (ER),androgen receptor (AR),progesterone receptor (PR) and human epidermal growth factor receptor-2 (HER-2).Conclusions There is a negative linear correlation between urinary iodine level and the size of primary focus of breast cancer,but it has nothing to do with lymph node metastasis and the expression of ER,AR,PR and HER-2.

Long-term prenatal stress increases susceptibility of N-methyl-D-aspartic acid-induced spasms in infant rats / 소아과

PURPOSE: Infantile spasms, also known as West syndrome, is an age-specific epileptic seizure. Most patients with this condition also exhibit delayed development. This study aimed to determine the effect of long-term prenatal stress on susceptibility to infantile spasms. METHODS: We subjected pregnant rats to acute or chronic immobilization stress. Resulting offspring received N-methyl-D-aspartic acid (15 mg/kg, intraperitoneally) on postnatal day 15, and their behaviors were observed 75 minutes after injection. The expression of KCC2 and GAD67 was also determined using immunohistochemistry. RESULTS: Exposure to long-term prenatal stress increased the frequency of spasms and decreased the latency to onset of spasms compared with offspring exposed to short-term prenatal stress. Expression of KCC2 and GAD67 also decreased in the group exposed to long-term prenatal stress compared with the group exposed to short-term prenatal stress. CONCLUSION: Our study suggests that exposure to long-term prenatal stress results in increased susceptibility to seizures.

Expression of Pendrin gene (SLC26A4) and protein in multinodular goiter / 中华内分泌外科杂志

Objective To explore the expression of the Pendrin gene (SLC26A4) and protein in multinodular goiter.Methods Thyroid tissues were obtained from 40 multinodular goiter patients undergoing surgery while the control group were obtained from 40 nomal thyroid tissues.RT-PCR was used to test SLC26A4 gene while western blot and immunohistochemistry were used to test Pendrin protein expression and distribution.Results SLC26A4 mRNA expression in multinodular goiter tissue was significantly increased in comparison with normal nodular tissues (t=2.663,P=0.011).Pendrin protein expression in multinodular goiter group was higher than that in normal tissue (t=2.286,P=0.026).The immunohistochemistry results showed that the Pendrin protein in multinodular goiter was mainly located in cytoplasm.There was positive expression in 24 patients (60％) in multinodular goiter group,while it was in 14 patients (35％) in the normal control group.The difference was significant (X2=5.013,P=0.025).Pendrin protein mainly expressed in cytoplasm in multinodular goiter tissue while it was mainly in cytomembrane in the normal control group.Conclusion SLC26A4 mRNA and its coding protein Pendrin expression are increased in multinodular goiter group,and mainly located in cytoplasm,indicating that iodide transporter function may be damaged when multinodular goiter occurs.

Effect of verapamil on expression of K+·Cl-cotransporter 2 in spinal dorsal horns during remifentanil-induced hyperalgesia in a rat model of incisional pain / 中华麻醉学杂志

Objective To evaluate the effect of verapamil on the expression of K+-Cl-cotransporter 2 (KCC2) in spinal dorsal horns during remifentanil-induced hyperalgesia in a rat model of incisional pain.Methods Thirty-two pathogen-free healthy adult male Sprague-Dawley rats,aged 6-7 weeks,weighing 250-300 g,were divided into 4 groups (n=8 each) using a random number table:control group (group C),incisional pain group (group Ⅰ),incisional pain plus remifentanil plus verapamil group (group I+R+ V) and incisional pain plus remifentanil group (group I+R).Normal saline was subcutaneously infused in group C.A 1 cm long incision was made in the plantar surface of the right hindpaw in anesthetized rats in group Ⅰ.Verapamil 5 mg/kg was intraperitoneally injected at 10 min before establishment of the incisional pain model in group I+R+V.In I+R and I+R+V groups,the model of incisional pain was established,and remifentanil was subcutaneously infused for 30 min at a rate of 80 μg · kg-1 · h-1 simultaneously.The mechanical paw withdrawal threshold (MWT) to yon Frey filament stimulation was measured at 1 day before establishment of the model (T0) and 2,6,24 and 48 h after establishment of the model (T1-4).The rats were sacrificed after measurement of MWT at T4,and the lumbar enlargement segments of the spinal cord were harvested for determination of the expression of KCC2 by immunofluorescence.Results Compared with group C,the MWT was significantly decreased at T1-4,and the expression of KCC2 was down-regulated in the other groups (P＜0.05).Compared with group Ⅰ,the MWT was significantly decreased at T1-4,and the expression of KCC2 was down-regulated in group I+R (P＜0.05).Compared with group I+R,the MWT was significantly increased at T1-4,and the expression of KCC2 was up-regulated in group I+R+V (P＜0.05).Conclusion The mechanism by which verapamil reduces remifentanil-induced hyperalgesia is related to up-regulation of the expression of KCC2 in spinal dorsal horns in a rat mnodel of incisional pain.

Role of hippocampal PKMζ/KCC2 pathway in propofol postconditioning-induced long-term cerebral protection following cerebral ischemia-reperfusion in rats / 中华麻醉学杂志

Objective To investigate the role of hippocampal protein kinase Mζ (PKMζ)/potassium-chloride cotransporter-2 (KCC2) pathway in propofol postconditioning-induced long-term cerebral protection following cerebral ischemia-reperfusion (I/R) in rats.Methods Sixty adult male Sprague-Dawley rats, weighing 250-280 g, were randomly divided into 5 groups (n =12 each): sham operation group (group S), cerebral I/R group (group I/R), propofol post-conditioning group (group P) , PKMζ inhibitor ZIP+cerebral I/R group (group Z+I/R) , and ZIP + propofol postconditioning group (group Z + P).Cerebral ischemia was induced by 1 h middle cerebral artery occlusion, followed by reperfusion in anesthetized rats.Propofol 20 mg · kg-1 · h-1was intravenously infused for 2 h in P and Z+P groups, and the equal volume of normal saline was given for 2 h in I/R and Z+I/R groups.In Z+P and Z+ I/R groups, ZIP 0.5 μmol/L was injected intravenously at 15 min before reperfusion.Modified Neurological Severity Score (mNSS) was assessed at 28 days of reperfusion.After the end of behavioral tests, the hippocampi were removed for determination of GABAergic interneurons GAD67/KCC2 positive neuron count in the hippocampal CA1 region (by using immunofluorescent staining), and PKMζ and phosphorylated KCC2 (p-KCC2) expression (by Western blot).Results Compared with group S, mNSS was significantly increased, GAD67/KCC2 positive neuron count was decreased, and the expression of PKMζ and p-KCC2 was down-regulated in I/R, P and Z+P groups (P＜0.05).Compared with group I/R, mNSS was significantly decreased, GAD67/KCC2 positive neuron count was increased, and the expression of PKMζ and p-KCC2 was up-regulated in group P, and mNSS was significantly increased, GAD67/KCC2 positive neuron count was decreased, and the expression of PKMζ and p-KCC2 was down-regulated in group Z+I/R (P＜0.05).Compared with group P, mNSS was significantly increased, GAD67/KCC2 positive neuron count was decreased, and the expression of PKMζ and p-KCC2 was down-regulated in group Z+P (P＜0.05).Conclusion The mechanism underlying propofol postconditioning-induced long-term cerebral protection following cerebral I/R may be related to activation of hippocampal PKMζ/KCC2 pathway in rats.

Effects of alcohol dependence on expression of spinal neuronal K+-Cl-cotransporter 2 in rats / 中华麻醉学杂志

Objective To evaluate the effects of alcohol dependence (AD) on the expression of spinal neuronal K+-Cl cotransporter 2 (KCC2) in rats.Methods Forty-eight healthy male Sprague-Dawley rats,weighing 200-250 g,were randomly divided into 2 groups (n =24 each) using a random number table:control group (group C) and group AD.An orogastric tube was inserted and alcohol was administered through the tube into the stomach to establish the model of AD.The concentration of ethanol was 5％,10％ and 20％ at 1st,2nd and 3rd weeks,respectively,and the concentration of ethanol was 35％ at 4th week and later.Alcohol was given at 10 ml · kg-1 · d-1,lasting for 8 weeks.The rats received drinking water containing no ethanol at 10 ml · kg-1 · d-1 instead of alcohol in group C.All the rats were allowed ad libitum access to food and water.Before the last administration,an elevated plus-maze test was performed for all the rats to observe their state of anxiety,which was used to evaluate the success of AD model.At the end of the last administration,the model of incisional pain was established.A 1-cm longitudinal incision was made through skin,fascia and muscle of the plantar aspect of the hindpaw in sevoflurane-anesthetized rats.At 2,6,24 and 48 h after operation,the mechanical and thermal paw withdrawal thresholds were measured.At 48 h after operation,the lumbar segment of the spinal cord was removed for determination of the expression of KCC2 by using immunofluorescence and Western blot.Results Compared with group C,the number of open arm entries was significantly reduced,the time spent on the open arms was shortened,the number of closed arm entries was increased,the time spent on the closed arms was prolonged,the mechanical and thermal paw withdrawal thresholds were decreased,and the expression of KCC2 was down-regulated in group AD.Conclusion Down-regulated expression of spinal neuronal KCC2 is involved in the mechanism of hyperalgesia in rats with AD.

Effects of propofol post-conditioning on hippocampal neuronal K+-Cl-co-transporter 2 expression in rats with cerebral ischemia/reperfusion injury / 中华麻醉学杂志

Objective To evaluate the effect of propofol post-conditioning on hippocampal neuronal K+-Cl-co-transporter 2 (KCC2) expression in the rats with cerebral ischemia/reperfusion (I/R) injury.Methods Seventy-two male Sprague-Dawley rats,aged 7-8 weeks,weighing 250-280 g,were randomly divided into 3 groups (n =24 each):sham operation group (group S),cerebral I/R (group I/R) and propofol post-conditioning group (group PP).The model of focal cerebral I/R injury was established by occlusion of the right middle cerebral artery.Propofol 20 mg· kg-1 · h-1 was infused over 2 h starting from the onset of reperfusion through the femoral vein in group PP.The equal volume of normal saline was given in S and I/R groups.Modified neurological severity score (mNSS) was used to evaluate the impairment of neurological function.The animals were then sacrificed and brains were removed for determination of the number of neurons (by Nissl' s staining) and expression of KCC2 (by immunofluorescence and Western blot) in hippocampal CA3 region.Results Compared with group S,the scores of mNSS were significantly increased,and the number of neurons and expression of KCC2 in hippocampal CA3 region were decreased in I/R group,and mNSS scores were increased,and no significant changes were found in the other parameters in group PP.Compared with group I/R,the mNSS scores were significantly decreased,and the number of neurons and expression of KCC2 in hippocampal CA3 region were increased in group PP.Conclusion The mechanism by which propofol post-conditioning reduces cerebral I/R injury is related to up-regulated expression of hippocampal KCC2 in rats.

Gitelman syndrome combined with complete growth hormone deficiency

Gitelman syndrome is a rare autosomal recessive hereditary salt-losing tubulopathy, that manifests as hypokalemic metabolic alkalosis, hypomagnesemia, and hypocalciuria. It is caused by mutations in the solute carrier family 12(sodium/chloride transporters), member 3 (SLC12A3) gene encoding the thiazide-sensitive sodium chloride cotransporter channel (NCCT) in the distal convoluted tubule of the kidney. It is associated with muscle weakness, cramps, tetany, vomiting, diarrhea, abdominal pain, and growth retardation. The incidence of growth retardation, the exact cause of which is unknown, is lower than that of Bartter syndrome. Herein, we discuss the case of an overweight 12.9-year-old girl of short stature presenting with hypokalemic metabolic alkalosis. The patient, on the basis of detection of a heterozygous mutation in the SLC12A3 gene and poor growth hormone (GH) responses in two provocative tests, was diagnosed with Gitelman syndrome combined with complete GH deficiency. GH treatment accompanied by magnesium oxide and potassium replacement was associated with a good clinical response.

Effect of sevoflurane on renal ischemia-reperfusion injury in rats and the role of Na+-2Cl--K+ cotransporter 1 and aquaporin 2 in it / 中华麻醉学杂志

Objective To investigate the effects of sevoflurane on renal ischemia-reperfusion (I/R) injury in rats and the role of Na+-2Cl--K+ cotransporter 1 (BSC1) and aquaporin 2 (AQP2) in it.Methods Twentyfour male Sprague-Dawley rats,aged 8-12 weeks,weighing 125-145 g,were randomly divided into 3 groups (n =8 each) ∶ sham operation group (S group),I/R group and sevoflurane group (Sev group).Renal ischemia was induced by occlusion of the renal artery for 45 min with atraumatic microclips followed by 24 h reperfusion.In group Sev,the rats inhaled 1 MAC (2.2％) sevoflurane,renal ischemia was induced after loss of consciousness and 1 MAC (2.2％) sevoflurane was inhaled for 1 h.The urine were collected at 24 h before I/R (T1) and 24 h of reperfusion (T2) for detection of urine specific gravity and creatinine (Cr) level.The urine volume was recorded.The endogenous creatinine clearance rate (Ccr) was calculated.Blood samples were taken from the irferior vena cava at T2 for determination of concentrations of serum blood urea nitrogen (BUN) and Cr and activities of superoxide dismutase (SOD) and myeloperoxidase (MPO),malondialdehyde (MDA) concentration.The left kidney was removed for determination of MPO and SOD activities and MDA content and for microscopic examination and the pathological changes of the renal tubule were scored.The expression of AQP2 and BSC1 was detected by immunohistochemistry and Western blot.Results Compared with group S,the urine volume was enlarged,concentrations of serum BUN and Cr were significantly increased,urine specific gravity and Ccr were significantly decreased,MPO and MDA levels were significantly increased,SOD activity was significantly decreased,the pathological score was significantly increased,and the expression of AQP2 and BSC1 was down-regulated in groups I/R and Sev (P ＜ 0.05).Cer was significantly higher,conceutratious of serum BUN and Cr and MPO and MDA levels were lower,SOD activity was higher,the pathological score was lower,and the expression of AQP2 and BSC1 was higher in group Sev than in group I/R (P ＜ 0.05).Sevoflurane inhalation significantly attenuated the pathological changes.Conclusion Sevoflurane can attenuate renal I/R injury in rats through up-regulating the expression of BSC1 and AQP2.

Topologia do simportador tireoideano sódio/iodeto / Topology of the thyroid sodium-iodine symporter

A síntese de hormônios tireoideanos depende fundamentalmente da captação de iodo do meio extracelular para o interior do tireócito. Esse processo é mediado por uma glicoproteína transmembrânica denominada simportador sódio/iodeto, que transporta iodeto para o interior do tireócito, juntamente com dois íons sódio em um processo de cotransporte. Esse processo é orquestrado pelo potencial eletroquímico gerado pela bomba Na+/K+ ATPïase dependente. O simportador sódio/iodeto também está envolvido no transporte ativo de iodeto em tecidos extratireoideos, tais como glândulas salivares, mucosa gástrica e a mama em lactação. A alta capacidade de acumular iodeto pelo tireócito constitui a base do diagnóstico cintilográfico e também da terapêutica com radioiodo em situações de hiperfunção tireoidea, como, por exemplo, na doença de Graves. Algumas mutações no simportador sódio/iodeto geram prejuízo no transporte de iodeto para o tireócito, resultando em hipotireoidismo congênito; além disso, o simportador sódio/iodeto pode tornar-se alvo de imunocomplexos, como, por exemplo, nas doenças tireoideanas autoimunes. Finalmente, o estudo molecular do simportador sódio/iodeto apresenta importância em muitas áreas, que compreendem desde proteínas transportadoras até o diagnóstico e tratamento de cânceres em tecidos tireoidianos e extratireoideos. Este artigo objetivou descrever o simportador sódio/iodeto presente na glândula tireoide, destacando sua sequência de resíduos de aminoácidos, topologia e todos os demais aspectos pertinentes a sua estrutura e função. Foi desenvolvido através de revisão sistemática da literatura nacional e internacional pelo indexador Medline/PubMed, utilizando os unitermos: iodeto, tireoide, transportador, topologia, sequência de resíduos de aminoácidos e estrutura

The synthesis of thyroid hormones depends essentially on the uptake of iodide by thyrocytes, which is mediated by an intrinsic membrane glycoprotein, the sodium-iodide symporter. The NIS actively cotransports a sodium cation and an iodide anion simultaneously. NIS-mediated transport of iodide is driven by the electrochemical sodium gradient generated by Na+/K+ ATPïase. Sodium-Iodide Symporter also mediates active iodide transport in other tissues, including salivary glands, gastric mucosa, and lactating mammary gland. The ability of the thyroid to accumulate iodide via NIS has long provided the basis for diagnostic scintigraphic imaging of the thyroid with radioiodine and served as an effective means for therapeutic doses of radioiodide to target and destroy hyperfunctioning thyroid tissue, as seen in Graves? disease. Another relevant clinical aspect of Sodium-Iodide Symporter is the fact that some spontaneous mutations have been identified as the cause of congenital iodide transport defect, resulting in hypothyroidism. Furthermore, the sodium-iodide symporter can become the target of autoantibodies, resulting in autoimmune thyroid diseases. Finally, the molecular analysis of NIS clearly holds the potential of having an even greater impact on a wide spectrum of s, ranging from the structure and function of transport proteins to the diagnosis and treatment of cancer, in thyroid and nonthyroid tissues. The aim of this paper is to describe the sodium/iodide symporter present in the thyroid gland, highlighting its sequence of amino acid residues, topology, and all other relevant aspects of structure and function. This study is based on a systematic review of the domestic and international literature found in Medline/ PubMed with the keywords: iodide, thyroid, carrier, topology, sequence of amino acid residues and structure

Water and Sodium Regulation in Heart Failure

Heart failure is the pathophysiological state characterized by ventricular dysfunction and associated clinical symptoms. Decreased cardiac output or peripheral vascular resistance lead to arterial underfilling. That is an important signal which triggers multiple neurohormonal systems to maintain adequate arterial pressure and peripheral perfusion of the vital organs. The kidney is the principal organ affected when cardiac output declines. Alterations of hemodynamics and neurohormonal systems in heart failure result in renal sodium and water retention. Activation of sympathetic nervous system, renin-angiotensin-aldosterone system and non-osmotic vasopressin release stimulate the renal tubular reabsorption of sodium and water. Dysregulation of aquaporin-2 and sodium transporters also play an important role in the pathogenesis of renal sodium and water retention.

Altered Regulation of Renal Sodium Transporters in Salt-Sensitive Hypertensive Rats Induced by Uninephrectomy

Uninephrectomy (uNx) in young rats causes salt-sensitive hypertension (SSH). Alterations of sodium handling in residual nephrons may play a role in the pathogenesis. Therefore, we evaluated the adaptive alterations of renal sodium transporters according to salt intake in uNx-SSH rats. uNx or sham operations were performed in male Sprague-Dawley rats, and normal-salt diet was fed for 4 weeks. Four experimental groups were used: sham-operated rats raised on a high-salt diet for 2 weeks (CHH) or on a low-salt diet for 1 week after 1 week's high-salt diet (CHL) and uNx rats fed on the same diet (NHH, NHL) as the sham-operated rats were fed. Expression of major renal sodium transporters were determined by semiquantitative immunoblotting. Systolic blood pressure was increased in NHH and NHL groups, compared with CHH and CHL, respectively. Protein abundances of Na+/K+/2Cl- cotransporter (NKCC2) and Na+/Cl- cotransporter (NCC) in the CHH group were lower than the CHL group. Expression of epithelial sodium channel (ENaC)-gamma increased in the CHH group. In contrast, expressions of NKCC2 and NCC in the NHH group didn't show any significant alterations, compared to the NHL group. Expressions of ENaC-alpha and ENaC-beta in the NHH group were higher than the CHH group. Adaptive alterations of NKCC2 and NCC to changes of salt intake were different in the uNx group, and changes in ENaC-alpha and ENaC-beta were also different. These altered regulations of sodium transporters may be involved in the pathogenesis of SSH in the uNx rat model.

Biochemical Characteristics of The Na-alpha-Ketoglutarate Cotransport System in Proximal Convoluted and Straight Tubules of the Rabbit Kidney / 대한신장학회잡지

PURPOSE: alpha-Ketoglutarate (alphaKG), a Krebs cycle intermediate, is extensively used in the kidney as a fuel substrate and as a counter anion for organic acid secretion. It is known to be taken up by the proximal tubule cells via the brush-border as well as basolateral membranes. We explored biochemical characteristics of the brush-border and basolateral alphaKG transport systems in pars convoluta and pars recta of the proximal tubule, respectively. METHODS: Brush-border and basolateral membrane vesicles (BBMV and BLMV) were isolated from rabbit renal outer cortex and outer medulla by Percoll gradient centrifugation. Vesicular uptake of alphaKG was determined by rapid Millipore filtration method using alpha-14[C]KG as a substrate. RESULTS: Both BBMV and BLMV showed a Na-gradient dependent uphill transport of alphaKG. The systems in both membranes were similarly inhibited by Li and activated by Na (Hill coefficient of 1.4). Kinetic analyses indicated that the Na-alphaKG cotransporters in the BBMV had a lower substrate affinity as compared with those in the BLMV. The transport systems in BLMVs showed a similar Km but different Vmax between the outer cortex (Km: 34 uM, Vmax: 3.3 nmol/mg protein/10s) and outer medulla (Km: 37, Vmax: 1.8). On the other hand, the systems in BBMVs were different in both Km and Vmax between the outer cortex (Km: 194, Vmax: 3.3) and outer medulla (Km: 89, Vmax: 1.7). CONCLUSION: The findings suggest that both axial and apical to basolateral heterogeneity of the Na-alphaKG cotransport system in proximal tubules may be due to a physiological adaptation to efficiently utilize alphaKG in the kidney.

Familial Gitelman Syndrome in Sisters / 대한신장학회잡지

Gitelman syndrome is a hereditary renal tubular disorder characterized by hypokalemia, metabolic alkalosis, hypomagnesemia, and hypocalciuria. This syndrome is caused by the genetic mutation of SLC12A3 gene encoding thiazide-sensitive sodium-chloride symporters in the apical membrane of distal convoluted tubular cells. Even though Gitelman syndrome is very similar to Bartter syndrome, it might be differentiated by hypomagnesemia, hypocalciuria, older onset age and higher prevalence rate. However, the precise diagnosis is made by gene variation through molecular genetic study. Herein, we report two cases of Gitelman syndrome in sisters diagnosed by familial genetic study.

Expressão do simportador sódio-iodo (NIS) nos tumores tireoidianos benignos e malignos através de estudo imunohistoquímico e da quantificação do RNA mensageiro / Expression of the sodium iodide symporter (NIS) in benign and malignant thyroid tumors using immunohistochemistry and mesenger RNA quantification

O transporte de iodo para tireóide é mediado pelo simportador sódio-iodo (NIS), glicoproteína de 643 aminoácidos localizada na região basolateral da célula folicular que acopla a entrada de sódio e iodo para o interior da célula. A clonagem do gene NIS em 1996 foi o primeiro passo na investigação dos mecanismos moleculares responsáveis pela diminuição da captação do radioiodo nos tumores benignos e malignos da tireóide. Estudos prévios sobre a expressão do gene NIS baseados em quantificação do transcrito e/ou análise imuno-histoquímica da proteína, mostraram resultados bastante divergentes. A maioria dos estudos com RT-PCR mostrou redução ou até ausência do transcrito do NIS. Os estudos mais recentes de imunohistoquímica, no entanto, mostraram aumento da expressão da proteína NIS, ao invés de diminuição. Poucos foram os estudos que fizeram análise do transcrito e da proteína concomitantemente nas mesmas amostras. Este estudo teve como objetivo quantificar o RNAm do gene NIS e avaliar a expressão e localização celular da proteína NIS, através das técnicas de RT-PCR em tempo real e exame imunohistoquímico, respectivamente. Foram estudadas 30 amostras de nódulos de tireóide, sendo 14 nódulos benignos e 16 nódulos malignos, sempre pareados com o tecido não-tumoral do mesmo paciente. Através de exame cintilográfico, verificou-se que 100% dos nódulos malignos e 85,7% dos benignos eram hipocaptantes. Houve diminuição da expressão gênica do NIS em 78,6% dos nódulos benignos, em 81,2% dos carcinomas utilizando o gene PSMC6 como controle interno e em 100% dos carcinomas com o gene GAPDH como controle interno. O exame imunohistoquímico da proteína NIS revelou positividade da proteína NIS no citoplasma em 100% dos tecidos não-tumorais, 100% dos nódulos benignos e 93,75% dos nódulos malignos, não sendo estatisticamente diferentes entre si. A positividade na membrana basolateral ocorreu em 23,3% das amostras não-tumorais, em 14,3%...

The iodide uptake by epithelial thyroid cells requires the expression of sodium iodide symporter (NIS), a transmembrane glycoprotein of 643 amino acids. NIS is located at basolateral plasma membrane of the thyroid follicular cells and couples the transport of iodide and sodium to this cells. NIS gene was cloned in 1996, being the first step of investigation of the mechanisms responsible for the lower uptake of radioiodide by benign and malignant thyroid tumors. Previous studies about expression of NIS gene based in quantification by RT-PCR and/or immunohistochemistry analysis showed divergent data. The majority of RT-PCR studies showed reduction or even absence of transcript of NIS in malignant tumors. Recent studies of immunostaining showed that many tumors overexpress rather than under express NIS. Only a few studies have made the analysis of the transcript and the protein at the same time in the same samples. The objective of this study was to investigate NIS transcript levels and the presence and location of NIS protein, using real time RT-PCR and immunohistochemistry, respectively. It was included 30 samples of thyroid tumors, 14 benign and 16 malignant ones, always compared to adjacent non-tumoral samples. Scintigraphic findings showed that 100% of malignant tumors and 87.5% of benign ones were ?cold?. RT-PCR data revealed lower gene expression in 78.6% of the benign tumors, 81.2% of the carcinomas using PSMC6 as a housekeeping gene and 100% of the carcinomas using GHPDH as a housekeeping gene, when paired to the normal tissue samples. Immunohistochemical staining revealed presence of NIS protein in 100% of the nontumoral samples, 100% of the benign tumors and 93.75% of the malignant tumors. No statistical differences were detect in this data. NIS protein was identified at basolateral membrane in 23.3% of non-tumoral samples, 14.3% of benign tumors and 12.5% of malignant tumors. No statistical differences were detect in this data...