OBJECTIVE: To establish an cell model of hyperparathyroidism by isolation, in vitro culture, and identification of parathyroid cells from patients with secondary hyperparathyroidism (SHPT). METHODS: The parathyroid gland tissues obtained from 10 patients with SHPT were dissociated by collagenase digestion for primary culture of the parathyroid cells. Morphological changes and growth characteristics of the cells were assessed by microscopic imaging and cell counting. The mRNA and protein expression levels of parathyroid hormone (PTH), calcium-sensing receptor (CaSR), and glial cells missing 2 (GCM2) in the primary and passaged cells were determined by immunofluorescence, qRT-PCR, and Western blotting. RESULTS: Primary cultures of parathyroid cells were successfully obtained. The cells exhibited a high expression of PTH shown by immunofluorescence assay and had a population doubling time of approximately 71.61 h. PTH secretion in the second-passage (P2) cells was significantly lower than that in the primary (P0) and first-passage (P1) cells (P < 0.001). Despite a significant downregulation of CaSR mRNA (P=0.017) and protein (P=0.006) in P1 cells as compared with P0 cells, no significant differences were found in mRNA and protein expressions of PTH or GCM2 between the two cell generations. CONCLUSION Primary cultures of parathyroid cells isolated from SHPT patients by collagenase digestion show similar biological properties to the cells in vivo.
Humans ; Hyperparathyroidism, Secondary/metabolism* ; Parathyroid Glands/metabolism* ; Parathyroid Hormone ; RNA, Messenger/metabolism* ; Receptors, Calcium-Sensing/metabolism*

OBJECTIVE: To investigate the change of calcium sensing receptor (CaSR) expression at different time in rat tissue with acute myocardial infarction (AMI) and its effect on cardiomyocyte apoptosis. METHODS: The healthy Wistar rats were randomly divided into Sham and AMI groups, the rat myocardial infarction model was established by ligating left anterior descending coronary artery. The changes of cardiac morphology and hemodynamics were detected at 1, 2 and 4 weeks,respectively. The expressions of CaSR mRNA and protein in myocardial tissue were detected by RT-PCR and Western blot, respectively. The expressions of Bax, Bcl-2, caspase-3 and caspase-9 proteins were detected by Western blot. The serum levels of lactate dehydrogenase (LDH), creatine kinase (CK) activity and cardiac troponin (cTnT) were determined. The apoptosis of cardiomyocytes were tested by TUNEL staining. RESULTS: Compared with the sham group, the expressions of CaSR mRNA and protein, the apoptosis index were increased significantly with the development of AMI (P＜0.05). The ultrastructural damage of cardiomyocytes was serious; the levels of LVSP, +dp/dt and -dp/dt were decreased,while the levels of LVEDP was increased (P＜0.05); In AMI group, the cTnT level, CK and LDH activities were all increased (P＜0.05). With the development of myocardial infarction, the cTnT level and CK activity were gradually decreased, while the activity of LDH was not significantly changed. The expressions of promote apoptosis-related Bax, caspase-3 and caspase-9 were significantly increased, and the expression of inhibited apoptosis-related protein(factor)Bcl-2 was significantly decreased (P＜0.05). CONCLUSION With the development of myocardial infarction,the expressions of CaSR mRNA and protein,the apoptosis index in rat myocardial tissue were increased with time prolongation after AMI. The increased expression of CaSR is involved in rat myocardial infarction, which is related with apoptosis.
Animals ; Apoptosis ; Myocardial Infarction ; metabolism ; Myocardium ; metabolism ; Random Allocation ; Rats ; Rats, Wistar ; Receptors, Calcium-Sensing ; metabolism

OBJECTIVE: To explore the expression levels of three T-type calcium channel receptors (α1G; α1H; α1I) in the cochlea and spiral ganglion neurons of C57BL/6J mice with different ages. METHOD: Thirty cases of C57BL/6J mice were divided into three groups (6-8 W, 24-26 W, 42-44 W) according to the age. The expressions of three T-type calcium channel receptors were quantified by RT-PCR after hearing thresholds measured by ABR. RESULT: Three receptors were detected in the cochlea and spiral ganglion neurons of 6-8 W C57BL/6J mice. The quantitative results showed that the expression levels of α1H and α1I were highest among three receptors in spiral ganglion neurons and in the cochlea respectively. The expression levels of three receptors significantly decreased with age,especially at the age of 4244 W. CONCLUSION The expression of T-type calcium channel receptors reduced with age in the inner ear of C57BL/6J mice.
Animals ; Calcium Channels ; Calcium Channels, T-Type ; biosynthesis ; Cochlea ; metabolism ; Ear, Inner ; Mice ; Mice, Inbred C57BL ; Neurons ; Receptors, Calcium-Sensing ; Spiral Ganglion ; metabolism

Animals ; Apoptosis ; Endotoxins/toxicity* ; Heart/drug effects* ; MAP Kinase Signaling System ; Myocardium/pathology* ; Rats ; Rats, Wistar ; Receptors, Calcium-Sensing/metabolism*

OBJECTIVETo observe the effect of hyperlipidemia and atherosclerosis on rat myocardial expression of calcium-sensing receptor and apoptosis.

METHODSThe rat atherosclerosis model was induced by intraperitoneal injection of VD(3) (6 x 10(5) U/kg) and high cholesterol diet. Wistar rats were divided into two groups: (1) Control group; (2) AS group (n = 12 each). The expressions of CaSR, Bcl-2, Bax and caspase-3 were analyzed by Western blot and RT-PCR. Apoptotic cells were observed by TUNEL assay. The morphological changes of abdominal aorta and cardiac tissues were observed under optical and electro microscopes. The activity of LDH, CK, SOD and the content of MDA were assayed with ultraviolet spectrophotometer. The level of cTnT was detected by electrochemical immunofluorescence.

RESULTSCompared with control group, the activity of LDH and CK, the content of MDA and cTnT, the apoptosis index, the expression of CaSR, Bax and caspase-3 were significantly increased, but the SOD activity and Bcl-2 expression were significantly decreased, the myocardial ultrastructure injury was significantly aggravated in the AS group (all P < 0.05).

CONCLUSIONHyperlipidemia and atherosclerosis can up-regulate myocardial calcium-sensing receptor expression, promote myocardial apoptosis, aggravate oxidative stress and myocardial ischemia.

Animals ; Apoptosis ; Atherosclerosis ; metabolism ; pathology ; Disease Models, Animal ; Female ; Hyperlipidemias ; metabolism ; pathology ; Male ; Myocardium ; metabolism ; Oxidative Stress ; Rats ; Rats, Wistar ; Receptors, Calcium-Sensing ; metabolism

OBJECTIVETo investigate the role of calcium-sensing receptor (CaR) on ischemia/reperfusion-induced rat cardiomyocyte apoptosis.

METHODSThe isolated rat hearts were subjected to 40 min ischemia followed by 2h of reperfusion with or without CaR agonist GdCl3 at the beginning of reperfusion. Control hearts (without ischemia) and ischemic hearts (40 min ischemia without reperfusion) served as controls. The protein expressions of CaR, Bcl-2 and cyt C were detected by Western blot. Cardiomyocyte apoptosis was detected by TUNEL. Mitochondrial potential (Deltaphim) was detected by laser confocal microscopy.

RESULTSCompared to controls groups, the expressions of CaR and apoptotic cells were significantly increased, Deltaphim and expressions of mitochondria cyt C and Bcl-2 were significantly reduced in ischemia/reperfusion hearts with or without GdCl3.

CONCLUSIONCaR was involved in the induction of cardiomyocyte apoptosis during ischemia/reperfusion via mitochondrial pathway.

Animals ; Apoptosis ; Disease Models, Animal ; Female ; Male ; Mitochondria, Heart ; metabolism ; Myocardial Ischemia ; metabolism ; Myocardial Reperfusion Injury ; metabolism ; Myocytes, Cardiac ; cytology ; Rats ; Rats, Wistar ; Receptors, Calcium-Sensing ; metabolism

OBJECTIVETo investigate the relationship between calcium-sensing receptor protein (CaSR) expression and rat cardiomyocyte apoptosis and related signal transduction pathways.

METHODSThe CaSR, BCl2, Caspase3 protein and ERK1/2 phosphorylation or non-phosphorylation were detected by Western blot. Cardiomyocyte apoptosis was detected by flow cytometry and immunofluorescence.

RESULTSCaSR protein was detected in rat cardiac tissue and CaSR activator gadolinium (GdCl3) induced cardiomyocyte apoptosis and increased ERK1/2 phosphorylation and expression of BCl2 and activated Caspase3. The selective mitogen-activated protein kinase (MAPK) inhibitor PD98059 abolished gadolinium -induced ERK1/2 activation and BCl2 expression, further increased the activation of Caspase3 and cardiomyocyte apoptosis.

CONCLUSIONOur results demonstrate the CaSR existence in cardiomyocytes and CaSR activation by gadolinium can induce myocyte apoptosis by activating Caspase3 and tyrosine protein kinase pathway.

Animals ; Apoptosis ; Caspase 3 ; metabolism ; Female ; Male ; Myocardium ; metabolism ; Myocytes, Cardiac ; metabolism ; RNA, Messenger ; biosynthesis ; Rats ; Rats, Wistar ; Receptors, Calcium-Sensing ; biosynthesis ; genetics ; Signal Transduction

OBJECTIVETo observe the dynamic expression of calcium-sensing receptor(CaSR) in myocardium of diabetic rats.

METHODSThirty male Wistar rats were randomly divided into 3 groups including control, diabetic-4 week and diabetic-8 week groups(n = 10). The type 2 diabetes mellitus models were established by intraperitoneal injection of streptozotocin (STZ, 30 mg/kg) after high-fat and high-sugar diet for one month. The cardiac morphology was observed by electron microscope. Western blot analyzed the expression of CaSR, phospholamban (PLN), a calcium handling regulator, and Ca+-ATPase(SERCA) in cardiac tissues.

RESULTSCompared with control group, the expressions of CaSR and SERCA were decreased, while the expression of PLN was significantly increased in a time-dependent manner in diabetic groups. Meanwhile diabetic rats displayed abnormal cardiac structure.

CONCLUSIONThese results indicate that the CaSR expression of myocardium is reduced in the progression of DCM, and its potential mechanism may be related to the imnaired intracellular calcium homeostasis.

Animals ; Calcium-Binding Proteins ; metabolism ; Diabetes Mellitus, Experimental ; complications ; Diabetes Mellitus, Type 2 ; Diabetic Cardiomyopathies ; metabolism ; physiopathology ; Disease Progression ; Heart ; physiopathology ; Male ; Myocardium ; metabolism ; pathology ; Rats ; Rats, Wistar ; Receptors, Calcium-Sensing ; metabolism ; Sarcoplasmic Reticulum Calcium-Transporting ATPases ; metabolism ; Streptozocin

This paper aims to investigate the effect of store-operated calcium channels (SOC) and receptor-operated calcium channels (ROC) on Ca(2+)-sensing receptor (CaR)-induced extracellular Ca(2+) influx and nitric oxide (NO) generation in human umbilical vein endothelial cells (HUVEC). SOC blocker, non-selective cation channel blocker, ROC agonist and ROC blocker were used separately and combined. Intracellular Ca(2+) concentration ([Ca(2+)]i) was measured by Fura-2/AM loading. The activity of endothelial nitric oxide synthase (eNOS) and the production of NO were determined by the DAF-FM diacetate (DAF-FM DA). The results showed that increases of [Ca(2+)]i, eNOS activity and NO generation induced by CaR agonist Spermine were all reduced after single blocking the SOC or ROC, respectively (P < 0.05). ROC agonist can partially abolish the ROC blocker's effect (P < 0.05). The above mentioned effects evoked by CaR agonist Spermine were further reduced when blocking both SOC and ROC than single blocking SOC or ROC in HUVEC (P < 0.05). In conclusion, these results suggest that the SOC and ROC participate in the processes of CaR-evoked extracellular Ca(2+) influx and NO generation by a synergistic manner in HUVEC.
Calcium ; physiology ; Calcium Channel Blockers ; pharmacology ; Calcium Channels ; physiology ; Calcium Signaling ; Fluoresceins ; pharmacology ; Human Umbilical Vein Endothelial Cells ; physiology ; Humans ; Nitric Oxide ; biosynthesis ; Nitric Oxide Synthase Type III ; metabolism ; Receptors, Calcium-Sensing ; physiology

Adult ; Aged ; Female ; Humans ; Hyperparathyroidism, Secondary ; metabolism ; pathology ; Immunohistochemistry ; Male ; Middle Aged ; Parathyroid Glands ; chemistry ; RNA, Messenger ; analysis ; Receptors, Calcium-Sensing ; analysis ; genetics ; Uremia ; metabolism