Value of Chloride Clearance Test in Differential Diagnosis of Gitelman Syndrome.

Objective To investigate the value of chloride clearance test in differential diagnosis of Gitelman syndrome (GS). Methods For patients with hypokalemic metabolic alkalosis and highly suspected GS,clinical data were documented and SLC12A3 gene screening was performed as gold standard to diagnose GS. Hydrochlorothiazide (HCT) test and furosemide (FUR) test were performed according to the standard process. Baseline and maximal increasement of chloride excretion fraction (FECl,the net and relative increase measured as εFECl) were compared between patients and controls to evaluated the reaction to the corresponding diuretics. Receiver operating characteristic (ROC) curve was used to evaluate the sensitivity and specificity of HCT test in GS diagnosis. Results Totally 27 patients and 20 health controls received HCT test. Among those patients,23 were diagnosed with GS genetically. When using the net and relative εFECl to diagnose GS,the areas under the ROC curve were 0.987 (95% CI:0.963～1.000,P<0.001) and 0.984 (95%CI:0.950～1.000,P<0.001),respectively. When a reasonable cutoff value for εFECl was selected,the sensitivity and specificity were both higher than 95%. Eight patients received both HCT test and FUR test. Five of them showed decreased reaction to HCT(net εFECl≤2.86% or relative εFECl≤223%),while normal reaction to FUR.SLC12A3 mutations confirmed their GS. Three patients with blunt reaction to FUR showed normal reaction to HCT,finally they were diagnosed as BS clinically because no SLC12A3 gene mutation was detected. Conclusion Comprehensive application of HCT test and FUR test to evaluate the diuretic reaction can effectively differentiate GS and BS.

Analysis of association among clinical features and shorter leukocyte telomere length in mitochondrial diabetes with m.3243A>G mitochondrial DNA mutation.

BACKGROUND: Mitochondrial diabetes is a kind of rare diabetes caused by monogenic mutation in mitochondria. The study aimed to summarize the clinical phenotype profiles in mitochondrial diabetes with m.3243 A>G mitochondrial DNA mutation and to investigate the mechanism in this kind of diabetes by analyzing the relationship among clinical phenotypes and peripheral leukocyte DNA telomere length. METHODS: Fifteen patients with maternally inherited diabetes in five families were confirmed as carrying the m.3243 A>G mitochondrial DNA mutation. One hundred patients with type 2 diabetes and one hundred healthy control subjects were recruited to participate in the study. Sanger sequencing was used to detect the m.3243 A>G mitochondrial DNA mutation. The peak height G/A ratio in the sequence diagram was calculated. Real-time polymerase chain reaction (PCR) was used to measure telomere length. RESULTS: The patients with mitochondrial diabetes all had definite maternally inherited history, normal BMI (19.5 ± 2.36 kg/m(2)), early onset of diabetes (35.0 ± 14.6 years) and deafness. The peak height G/A ratio correlated significantly and negatively with the age at onset of diabetes (≦ 25 years, 61.6 ± 20.17%; 25-45 years, 16.59 ± 8.64%; >45 years, 6.37 ± 0.59%; p = 0.000). Telomere length was significantly shorter among patients with mitochondrial diabetes and type 2 diabetes than in the control group (1.28 ± 0.54 vs. 1.14 ± 0.43 vs. 1.63 ± 0.61; p = 0.000). However, there was no significant difference between patients with mitochondrial diabetes and those with type 2 diabetes. There was no correlation between telomere length and the peak height G/A ratio. CONCLUSION: Deafness with definite maternal inheritance and normal BMI, associated with elevated blood lactic acid and encephalomyopathy, for the most part, suggest the diagnosis of mitochondrial diabetes . The peak height G/A ratio could reflect the spectrum of age at onset of the disease. Telomere length was shorter in patients with mitochondrial diabetes and those with type 2 diabetes, which suggests that the shorter telomere length is likely involved in the pathogenesis of diabetes but is not specific for this kind of diabetes.

[Clinical manifestations, therapeutic response to tyrosinase inhibitor and RET gene activating mutation in a patient with multiple endocrine neoplasia 2B].

OBJECTIVE: To explore the clinical manifestations, therapeutic response and RET gene mutation in a patient with multiple endocrine neoplasia 2B (MEN2B) characterized by medullary thyroid carcinoma (MTC), bilateral adrenal pheochromocytoma and multiple mucosal neuromas. METHODS: The clinical features, laboratory data and radiological manifestations of this patient were collected. Genomic DNA was extracted from her peripheral blood leukocytes and her parents. Tenth to sixteenth exons of RET proto-oncogene, including the flanking regions of introns, were amplified by polymerase chain reaction (PCR). And the mutations of RET proto-oncogene were identified by direct sequencing. RESULTS: MEN-2B was diagnosed by the clinical presentations, laboratory tests and radiological findings. Gene analysis confirmed heterozygous mis-sense mutation at codon 918 in exon 16 of RET proto-oncogene in which thymine was replaced by cytosine (ATG→ACG). Her thyroid medullary carcinoma was treated by radical operations and radiotherapy. Tyrosinase inhibitor sorafenib was administered for 2 months and watery diarrhea and cough were alleviated. The drug was withdrawn because of such intolerant side effects as hair loss and painful rashes. She had a survival time of over 14 years with multiple system tumor metastases. CONCLUSIONS: The mutation analysis of RET proto-oncogene confirmed the diagnosis of MEN2B in respect of molecular genetics. For patients with advanced MTC, tyrosinase inhibitors may relieve the symptoms and provide a new therapeutic choice.

[Differences of blood plasma renin activity, angiotensin II and aldosterone levels in essential or secondary hypertension].

OBJECTIVE: To study on the difference of plasma renin activity (PRA), angiotensin II (Ang II), and aldosterone levels in patients with essential hypertension (EH) or primary aldosteronism (PA) or pheochromocytoma (PHEO), and to analyze the sensitivity and specificity on the diagnosis of PA among patients with hypertension with aldosterone/PRA ratio (ARR). METHODS: The plasma aldosterone, Ang II and PRA concentrations in supine and upright positions were measured by radioimmunoassay from 413 patients including idiopathic hyperaldosteronism (IHA, n = 111), aldosterone-producing adenoma (APA, n = 118), PHEO (n = 98) and EH (n = 86). ARR was calculated. RESULTS: Plasma aldosterone concentrations in both of supine and upright positions in PHEO group [374 (294, 465) pmol/L and 629 (449, 997) pmol/L] and PA group [471 (346, 632) pmol/L and 673 (499, 825) pmol/L] were higher than those in EH group [277 (224, 332) pmol/L and 427 (341, 501) pmol/L] (P < 0.01). They were also higher in APA group [576 (416, 731) pmol/L and 726 (554, 906) pmol/L] than those in IHA group [399 (313, 504) pmol/L and 609 (485, 776) pmol/L] (P < 0.01). Ang II levels in both positions were lower in PA group [43.2 (26.4, 74.4) ng/L and 60.1 (38.5, 103.6) ng/L] than in EH group [56.7 (43.3, 78.9) ng/L and 84.3 (61.3, 108.4) ng/L] or PHEO group [54.3 (29.9, 101.5) ng/L and 102.8 (49.9, 167.0) ng/L] (all P values < 0.01), and there was no difference between IHA and APA group (P > 0.05). The PRA level in both positions of each group were PHEO group [0.3 (0.2, 1.0) µg · L(-1) · h(-1) and 1.4 (0.6, 3.4) µg · L(-1) · h(-1)] > EH group [0.2 (0.1, 0.4) µg · L(-1) · h(-1) and 0.6 (0.4, 1.0) µg · L(-1) · h(-1)] (P < 0.01) > PA group [0.1 (0.1, 0.1) µg · L(-1) · h(-1) and 0.2 (0.1, 0.3) µg · L(-1) · h(-1)] (P < 0.01), and APA group [0.1 (0.1, 0.1) µg · L(-1) · h(-1) and 0.1 (0.1, 0.3) µg · L(-1) · h(-1)] < IHA group [0.1 (0.1, 0.2) µg · L(-1) · h(-1) and 0.2 (0.1, 0.3) µg · L(-1) · h(-1)] (supine P < 0.01; upright P < 0.05). APA was divided into 2 types with renin-Ang II-responsive APA (n = 26) and unresponsive APA (n = 92). The plasma aldosterone concentration was lower in supine position but higher in upright position in renin-Ang II-responsive APA than in unresponsive APA patients. ARR in upright was higher in PA group (P < 0.01) but lower in PHEO group (P < 0.05) compared with EH. ARR was higher in APA than in IHA (P < 0.01). The sensitivity and specificity of ARR as 40 (aldosterone unit: ng/dl; PRA unit: µg · L(-1) · h(-1); its value should multiply 27.7 when transferred to pmol/L, simili) were 93% and 76%, respectively. CONCLUSION: The levels of PRA, Ang II and aldosterone from patients with EH, PA and PHEO are significant different. ARR as 40 in upright position could be used for PA screening cutoff point.

[An analysis of hyperinsulinemia in Bartter syndrome].

OBJECTIVE: To analyse hyperinsulinemia in Bartter syndrome. METHODS: Twenty-three cases of Bartter syndrome [age (27 ± 9) years; fasting serum potassium (2.8 ± 0.5) mmol/L], 20 patients of aldosterone-producing adenoma [APA, age (45 ± 11)years, fasting serum potassium (3.0 ± 0.4) mmol/L], 20 patients of idiopathic hyperaldosteronism [IHA, age (51 ± 11) years, fasting serum potassium (3.4 ± 0.2) mmol/L] were diagnosed in Peking Union Medical College Hospital from September 2003 to May 2008. All patients underwent 3-hours oral glucose tolerance test (3hOGTT), postural stimulation test and calculated HOMA-insulin resistance (HOMA-IR) and HOMA-insulin sensitivity (HOMA-IS) by Homeostasis model. RESULTS: The insulin area under curve[(229.0 ± 162.4) mIU×L(-1)×h] was significantly higher than APA group [(121.2 ± 81.1) mIU×L(-1)×h, P < 0.05] and were similar to the aged-matched patients with IHA [(227.7 ± 158.6) mIU×L(-1)×h]. But HOMA-IR in Bartter group were similar to APA group (1.96 ± 1.14 vs 1.41 ± 0.91), and HOMA-IR in APA group was lower than IHA group (1.96 ± 1.14 vs 2.40 ± 1.60, P < 0.05). There was no deference in HOMA-IS among three groups, but APA group had lower level. In all three groups, the peak of insulin secretion was delayed. CONCLUSION: Bartter syndrome patients commonly present with hyperinsulinemia.

[Relationship between plasma level of leptin and the expression of leptin receptor in human adrenal tissues and tumors].

OBJECTIVE: To compare the mRNA, protein expression of long leptin receptor (Ob-Rb) in human adrenal tissues and tumors and observe the plasma level of leptin in primary aldosteronism (PA), cortisol-secreting tumors (CS) and pheochromocytomas (PHEO). METHODS: Total RNA and protein were extracted from 6 normal human adrenal glands, 10 CS, 20 PHEO; and 14 aldosterone-producing adenomas (APA) (RNA), 10 APA (protein); plasma samples were drawn from 20 controls, 15 PHEO, 29 PA and 11 CS. RESULTS: The mRNA and protein of Ob-Rb were widely expressed in human adrenal glands and tumors. The mRNA (0.32±0.12) and protein (1.31±0.26) expressions of Ob-Rb were higher in normal human adrenal cortex (C) than all other tissues (P<0.05) while the mRNA expression of Ob-Rb in APA (0.15±0.10) was higher than CS (0.05±0.02) (P<0.05). The mRNA expression of Ob-Rb in APA was positively correlated with plasma supine aldosterone level (r=0.670, P=0.024). The mRNA expression of Ob-Rb in CS was positively correlated with 24-hour urinary free cortisol level (r=0.870, P=0.005). The plasma level of leptin was higher in CS than in non-CS groups (P=0.001). CONCLUSIONS: Ob-Rb is widely expressed in adrenal tissues and tumors. There is a differential expression in various tissues. Further studies are warranted to understand the relationship between leptin and adrenal gland.

[Adrenal lesions in patients of multiple endocrine neoplasia type 1].

OBJECTIVE: To investigate the prevalence and characteristics of adrenal lesions in Chinese multiple endocrine neoplasia type 1 (MEN-1) patients. METHODS: Adrenal CT scan and clinical manifestations were retrospectively reviewed in 32 consecutive MEN-1 patients who were evaluated at our hospital during January 1986 to December 2009. RESULTS: Adrenal lesions were identified in 16 of 32 (50%) MEN-1 patients. Five (31.3%) patents with adrenal involvement showed bilateral lesions, including bilateral adenoma (n=1), bilateral hyperplasia (n=2) and adenoma and hyperplasia on each side (n=2). Unilateral adrenal lesion was presented in 11 (68.7%) patients. Among which, 63.6% had adenomas with a mean diameter of 2.3 cm (0.8-4.0 cm) and the remainder was of hyperplasia or enlargement. In two patients, functioning adrenal abnormalities were detected including Cushing adenoma (n=1) and aldosterone-secreting adenoma (n=1). CONCLUSIONS: The prevalence of adrenal lesion in MEN-1 patient is similar between China and western countries. These tumors are mostly benign, small and nonfunctioning. Taking into account a high incidence of adrenal carcinoma in previous foreign studies, routine screening and close surveillance are still recommended for adrenal lesions in MEN-1 patients.

Heteroplasmy level of the mitochondrial tRNaLeu(UUR) A3243G mutation in a Chinese family is positively associated with earlier age-of-onset and increasing severity of diabetes.

OBJECTIVE: To investigate the mutations of mitochondrial genome in a pedigree with suspected maternally inherited diabetes and deafness and to explore the correlations between the mutations and clinical features. METHODS: Genomic DNA was isolated from blood leucocytes of each member of the pedigree. The mitochondrial genome was amplified with 24-pair primers that could cover the entire mitochondrial DNA. Direct sequencing of PCR products was used to identify any mitochondrial DNA mutations. RESULTS: Family members on the maternal side all harbored the tRNALeu(UUR) A3243G mutation. The paternal side family members did not have the mutation. The age-of-onset of diabetes of the 4 maternal side family members was 15, 41, 44, and 65 years old, and their corresponding heteroplasmy level of the mutation was 34.5%, 14.9%, 14.6%, and 5.9%, respectively. The age-of-onset of diabetes and heteroplasmy level of A3243G mutation were negatively correlated with a correlation coefficient of -0.980 (P = 0.02). Meanwhile, patient with high heteroplasmy level of A3243G mutation had relatively low severity of disease. Moreover, 6 reported polymorphisms and 2 new variants were found. CONCLUSIONS: The main cause of diabetes in this pedigree is the tRNALeu(UUR) A3243G mutation. However, other gene variants may contribute to its pathogenicity. The heteroplasmy level of the tRNALeu(UUR) A3243G mutation is positively associated with earlier age-of-onset and increasing severity of diabetes.

Bilateral pheochromocytoma as first presentation of von Hippel-Lindau disease in a Chinese family.

OBJECTIVE: To investigate the clinical and genetic features of a Chinese family with von Hippel-Lindau (VHL) disease revealed by bilateral pheochromocytoma. METHODS: The proband and other members in a Chinese family with familial pheochromocytoma were clinically evaluated and followed up. Genomic DNA extracted from the peripheral blood of 8 family members (including 3 patients) was amplified by polymerase chain reaction (PCR) and the PCR products were directly sequenced. RESULTS: The first presentation in the proband, his mother, and his sister was bilateral pheochromocytoma, and the missense mutation of 695G-A (Arg161Gln) in exon 3 of VHL gene was detected in the three patients. In the follow-up study, the proband and his mother were found to have other VHL tumors, induding retinal and cerebellar hemangioblastomas and pancreatic tumor. Neither clinical presentation of VHL disease nor gene mutation was found in other family members. CONCLUSION: VHL disease should be suspected in some patients with familial pheochromocytoma, and VHL gene screening helps to achieve early diagnosis of the disease.

Clinical Characteristics of Wolfram Syndrome in Chinese Population and a Novel Frameshift Mutation in WFS1.

OBJECTIVE: Wolfram syndrome (WS) is a rare, degenerative, and hereditary disorder characterized by ear diabetes mellitus (DM) and optic atrophy (OA). We aim to characterize clinical features in Chinese patients who had been poorly studied until now. METHODS: We performed a retrospective review of patients with WS seen in the Peking Union Medical College Hospital from 2002 to 2017. Data including demographic data, clinical presentations, examination results, family history, and genetic analysis were described. RESULTS: Six patients with WS were identified, meeting the diagnostic criteria of the coincidence of DM and OA before 15 years old or the existence of two WFS1 mutations. All were male, with the median age of 14.5 years (range 10-19 years). Blood glucose impairment, OA, and diabetes insipidus were present in all (100%), hearing impairment in four (66.7%), urological abnormalities in four (66.7%), neurological abnormalities in one (16.7%), and endocrine disorder in one (16.7%). Rare presentation includes cataract, glaucoma, and spina bifida occulta. Diabetes was insulin-dependent and not ketosis onset, with antibody to glutamic acid decarboxylase and islet cell negative. Genetic analysis revealed mutations in WFS1 in three patients. A novel frameshift mutation (p.Asp151Glufs*93) was identified in exon 4 of WFS1. CONCLUSION: Our series of WS patients indicated that WS is a degenerative disease with a wide and variable spectrum, characterized by ear non-autoimmune DM and bilateral OA. Genetic analysis is recommended when suspected of WS.

Expression and effect of transforming growth factor-alpha and tumor necrosis factor-alpha in human pheochromocytoma.

This study observed the expression of transforming growth factor-alpha (TGF-alpha) and tumor necrosis factor-alpha (TNF-alpha) in pheochromocytoma (PHEO) tissue and examined their effects on the proliferation and apoptosis of human PHEO cells. The mRNA and protein expressions of TGF-alpha and TNF-alpha were higher in PHEO tissues than in normal adrenal medullary tissues, and their expressions varied with pathological features. TGF-alpha and TNF-alpha stimulated the proliferation of primary human PHEO cells, but had no effect on the cell apoptosis. Both TGF-alpha and TNF-alpha might be involved in the pathogenesis of human PHEO. TNF-alpha needs to be further investigated before its treatment of PHEO can be realized in clinical practice.

von Hippel-Lindau gene mutation in non-syndromic familial pheochromocytomas.

Approximately 50% of patients with non-syndromic familial pheochromocytomas had germline von Hippel-Lindau (VHL) gene mutations, but no reports on the subject were available in China. A total of five unrelated Chinese families with non-syndromic familial pheochromocytomas were screened for VHL gene mutation by polymerase chain reaction (PCR) and subsequent direct sequencing. Missense germline mutations of VHL gene were detected in four of the five families. Arg161Gln (695G-A) mutation was found in two families, and the other two families had Leu163Phe (700C-T) and Arg167Trp (712C-T) mutation, respectively. In conclusion, VHL gene may have frequent mutation in Chinese patients with non-syndromic familial pheochromocytomas.

Expression and effect of adrenomedullin in pheochromocytoma.

This study investigates the expression of human adrenomedullin (ADM) and its receptor-receptor activity modifying protein 2/calcitonin receptor-like receptor (RAMP2/CRLR) mRNA in pheochromocytoma by reverse transcriptase polymerase chain reaction (RT-PCR) and its effect on the proliferation of pheochromocytoma cells by MTT. The mRNA expression of ADM and its receptor RAMP2/CRLR was present in normal adrenal medulla and pheochromocytoma tissues. The mRNA expression of ADM, RAMP2, and CRLR is markedly higher in pheochromocytomas than in normal medulla. ADM inhibits the proliferation of human pheochromocytoma cells and exerts a possible autocrine or paracrine effect in the adrenal.

The effects of urotensin-II on proliferation of pheochromocytoma cells and mRNA expression of urotensin-II and its receptor in pheochromocytoma tissues.

This study was conducted to investigate the effects of urotensin-II (UII) on the proliferation of pheochromocytoma cells and the mRNA expression of UII and its receptor G protein-coupled receptor 14 (GPR14) in normal adrenal and human pheochromocytoma tissues. The effects on the cell proliferation by different UII concentrations and at different time were observed with the MTT method in both rat pheochromocytoma cell line (PC12 cell) and human pheochromocytoma cells. The mRNA expression of UII and GPR14 was evaluated by RT-PCR. UII had no significant effect on the proliferation in PC12 cells, but promoted the proliferation of human pheochromocytoma cells. The mRNA expression of UII and GPR14 in pheochromocytoma was lower than that in normal adrenal tissues. But mRNA expression of UII and GPR14 in adrenal pheochromocytomas was lower than that in extra-adrenal pheochromocytomas. Thus, UII and its receptor GPR14 exert a possible effect in the pathogenesis of pheochromocytoma.

[Expression of renin-angiotensin-aldosterone system in human adipose tissues].

OBJECTIVE: To compare the mRNA expression of renin-angiotensin-aldosterone system in human subcutaneous and visceral adipose tissues. METHODS: Total RNA was extracted from 12 human subcutaneous adipose tissues, 12 perirenal adipose tissue and 9 periadrenal adipose tissues. The expressions of angiotensinogen ( AGT) , renin, angiotensin converting enzyme ( ACE) , angiotensin converting enzyme 2 (ACE2), angiotensin I1 receptor type 1 (AT1), angiotensin II receptor type 2 (AT2 ), CYP11 B2, and their internal reference glyceraldehyde phosphate (GAPDH) were studied by reverse transcription-polymerase chain reaction. The ratios of each target genes were used to evaluate the expression levels of AGT, renin, ACE, ACE2, AT1, AT2, and CYP11B2 in different adipose tissues. RESULTS: The mRNA expressions of AGT, ACE, ACE2, AT1, and AT2 were detected in human subcutaneous, perirenal, and periadrenal adipose tissues. However, CYPI B2 mRNA expression was not found in these three adipose tissues. The mRNA expressions of renin was only detected in perirenal and periadrenal adipose tissues, which was significantly higher in perirenal adipose tissues than in periadrenal adipose tissues ( P < 0. 05 ). The mRNA expressions of ACE and ACE2 in perirenal adipose tissues were significantly higher than that in subcutaneous adipose tissues ( P < 0. 05). The mRNA expressions of ACE were significantly higher than that of ACE2 in subcutaneous, perirenal, and periadrenal adipose tissues (P <0. 05). The mRNA expressions of AT1 were significantly lower than that of AT2 in periadrenal adipose tissues (P < 0. 05). CONCLUSION: Local renin-angiotensin system exists in the adipose tissues; however, aldosterone is not synthesized in the adipose tissues.

[Effect of hypokalemia on glucose metabolism in primary hyperaldosteronism].

OBJECTIVE: To investigate the effect of potassium deficiency on glucose and insulin metabolism in primary hyperaldosteronism, including aldosterone-producing adenoma (APA) and idiopathic hyperaldosteronism (IHA). METHODS: Totally 178 patients who were diagnosed as primary hyperaldosteronism (103 patients with APA and 75 with IHA) were divided into hypokalemia group and normal potassium group according to their serum potassium levels. All patients received 3 hours of oral glucose tolerance test and aldosterone test to observe the relationship among glucose, insulin and serum potassium. RESULTS: Area under curve of serum potassium, area under curve of plasma insulin, and fasting serum insulin were significantly lower in the hypokalemia group than in the normal potassium group (P <0. 05, P <0. 01); area under curve of glucose and aldosterone level were significantly higher in the hypokalemia group than in the normal potassium group ( P < 0. 05 ) . The prevalence of metabolic syndrome was significantly higher in IHA than in APA (57. 3% vs 38. 8% ; P < 0. 05). CONCLUSION: Hypokalemia may play an important role in inhibiting insulin secretion in primary hyperaldosteronism.

Interaction between Angiotensin II and Insulin/IGF-1 Exerted a Synergistic Stimulatory Effect on ERK1/2 Activation in Adrenocortical Carcinoma H295R Cells.

The cross talk between angiotensin II (Ang II) and insulin has been described mainly in cardiovascular cells, hepatocytes, adipocytes, and so forth, and to date no such cross talk was reported in adrenal. In this study, we examined the interaction between Ang II and insulin/IGF-1 in ERK and AKT signaling pathways and expression of steroidogenic enzymes in H295R cells. Compared to the control, 100 nM Ang II increased phospho-ERK1/2 approximately 3-fold. Insulin (100 nM) or IGF-1 (10 nM) alone raised phospho-ERK1/2 1.8- and 1.5-fold, respectively, while, after pretreatment with 100 nM Ang II for 30 min, insulin (100 nM) or IGF-1 (10 nM) elevated phospho-ERK1/2 level 8- and 7-fold, respectively. The synergistic effect of Ang II and insulin/IGF-1 on ERK1/2 activation was inhibited by selective AT1 receptor blocker, PKC inhibitor, and MEK1/2 inhibitor. Ang II marginally suppressed AKT activation under the basal condition, while it had no effect on phospho-AKT induced by insulin/IGF-1. Ang II significantly stimulated mRNA expression of CYP11B1 and CYP11B2, and such stimulatory effects were enhanced when cells were cotreated with insulin/IGF-1. We are led to conclude that Ang II in combination with insulin/IGF-1 had an evident synergistic stimulatory effect on ERK1/2 activation in H295R cells and the effect may be responsible for the enhanced steroid hormone production induced by Ang II plus insulin/IGF-1.

[Clinical analysis of 25 patients with bilateral pheochromocytomas].

OBJECTIVE: Bilateral pheochromocytomas are rare diseases. The purpose of this retrospective study was to elucidate the clinical characteristics of patients with bilateral pheochromocytomas. METHODS: We analyze the clinical data of 25 patients with bilateral pheochromocytomas who were treated at Peking Union Medical College Hospital between 1952 and 2004. RESULTS: The average age at diagnosis was (32 +/- 14) years. 19 cases (76%) were familiar type, and among the 19 cases, 13 cases were multiple endocrine neoplasia (MEN), 5 cases von Hippel-Lindau (vHL) disease and 1 case of isolated familial pheochromocytomas. In the 25 patients, bilateral pheochromocytomas were discovered at the same time in 88%, and multiple tumors existed in at least one side of the adrenal gland in 56%. 50% of cases recurred after resection of pheochromocytomas. CONCLUSIONS: Hereditary syndromes should be screened when pheochromocytoma is bilateral, and the patients' family members also should be screened for hereditary syndromes. During operation for bilateral adrenal pheochromocytoma, multiple tumors in one side should be considered. Long-term follow-up is necessary because recurrence may develop many years after operation.

[Expression of urotensin II and G-protein coupled receptor 14 mRNA in human pheochromocytoma tissues].

OBJECTIVE: To investigate the expression of urotensin II (U II) and G-protein coupled receptor 14 (GPR14) mRNA in human pheochromocytoma tissues. METHODS: Total RNA from normal adrenal and pheochromocytoma tissues was extracted. The reverse transcription-polymerase chain reaction method was used to evaluate the levels of U II and GPR14 mRNA expression in human pheochromocytoma tissues. RESULTS: There was no significant difference of U II and GPR14 mRNA expression between normal adrenal cortex and medulla. The expression of U II and GPR14 mRNA in pheochromocytoma was significantly lower than that in normal adrenal cortex and medulla (P < 0.05). The expression of GPR14 mRNA in adrenal pheochromocytomas was significantly lower than that of extra-adrenal pheochromocytomas (P < 0.05). CONCLUSION: U II and GPR14 may play a role in the pathogenesis and hypertension regulating of pheochromocytoma.

[Expression of adrenomedullin and its receptor mRNA in the tissues of normal adrenal medulla and pheochromocytoma].

OBJECTIVE: To investigate the expression of human adrenomedullin (ADM) and its receptor-receptor activity modifying protein 2/calcitonin receptor-like receptor (RAMP2/CRLR) mRNA in the tissues of normal adrenal medulla and pheochromocytoma. METHODS: Total RNA was extracted from normal adrenal medulla and pheochromocytomas. The expression of ADM and RAMP2/CRLR mRNA were studied by reverse transcription-polymerase chain reaction. The ratios of ADM/GAPDH, RAMP2/ GAPDH, CRLR/GAPDH were used to evaluate the expression levels of ADM, RAMP2 and CRLR mRNA. RESULTS: Expressions of ADM and its receptor- RAMP2/CRLR mRNA were detected in normal adrenal medulla and pheochromocytoma tissues. ADM/GAPDH were 0.48+/-0.09 and 0.75+/-0.24, RAMP2/ GAPDH 0.79+/-0.12 and 1.29+/-0.30, CRLR/GAPDH 0.40+/-0.08 and 0.87+/-0.22 in normal adrenal medulla and pheochromocytomas, respectively (P < 0.05). CONCLUSION: ADM exerts a possible autocrine or paracrine effect in the adrenal. ADM may be involved in the pathogenesis of pheochromocytoma.