Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

37 patients with obvious pregnancy-induced hypertension, 56 normal pregnant women and 40 nonpregnant women in the same age groups were tested on their serum calcium(Ca), phosphorus(P) alkaline phosphatase(AKP), parathyroid hormone(PHT) and calcitonin(CT). Results indicated that the respective means of serum Ca and CT were statistically lower (P < 0.05), while AKP and PTH were higher (P < 0.01) than that of normal pregnant women. It was also confirmed that Ca metabolism of patients with pregnancy-induced hypertension was obviously abnormal. In addition, pathogenesis of pregnancy-induced hypertension was also discussed.
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PMID:[Observation and analysis on metabolism of serum calcium and phosphorus in patients with pregnancy-induced hypertension]. 1092 Nov 21

Calbindin-D28k is an intracellular protein with high affinity for calcium. In the kidney, this protein is exclusively localized in the distal tubule and in the proximal part of the collecting ducts. Functionally, calbindin-D28k is supposed to be involved in the regulation of the reabsorption of calcium and possibly magnesium in the distal nephron though the exact regulatory mechanisms are not yet known. Thus, several theories regarding the functional role of calbindin-D28k have been proposed: The carrier theory describes calbindin-D28k as a transport protein which binds calcium and then transports it from the luminal to the basolateralcell membrane. The buffer theory assumes that calbindin-D28k functions by binding calcium ions to prevent intracellular calcium concentrations from reaching toxic levels. The activator theory describes that calbindin-D28k increases the activity of calcium channels or the enzymatic activity of the Ca++-Mg++-ATPase in the luminal membrane and thereby increases the tubular reabsorption of calcium. The renal calbindin-D28k is dependent upon vitamin D. Pharmacological doses of the active vitamin D metabolite 1,25-(OH)2D increases the concentrations of renal calbindin-D28k, whereas the concentration of calbindin-D28k is low in conditions with reduced levels of circulating 1,25-(OH)2D. Likewise, plasma calcium concentrations, uremia and hypertension affect calbindin-D28k expression. However, several studies have rendered probable the effect of additional factors in the regulation of renal calbindin-D28k. The aim of the present dissertation therefore was to examine the regulation of renal calbindin-D28k in a series of physiological and pathophysiological conditions established in vivo in the rat. A possible correlation between hypertension and calbindin-D28k was examined in three models of experimental hypertension: the genetically defined spontaneous hypertensive rat, the salt-sensitive Dahl rat and the renovascular hypertensive rat. These three models clearly demonstrated three separate patterns in the calcium metabolism, but the studies were unable to support a role for calbindin-D28k in the development of hypertension. In all three models the development of hypertension caused an increased plasma 1,25-(OH)2D. This increase was accompanied by either unaltered or reduced levels of renal calbindin-D28k possibly secondary to a cellular resistance against 1,25-(OH)2D. Magnesium binds to calbindin-D28k with a relatively high affinity. The regulation of urinary magnesium excretion takes place in the distal tubule where calbindin-D28k is found in high concentrations. Therefore, a possible relation between magnesium and calbindin-D28k was examined. The studies demonstrated not previously known connections between magnesium intake, urinary magnesium excretion and renal calbindin-D28k which suggests that this protein is involved in the regulation of magnesium homeostasis by the kidney. Calcitonin increases the reabsorption of calcium in the distal tubule. Therefore, the effect ofcalcitonin on renal calbindin-D28k was examined both by eliminating the endogeneous calcitonin production by a selective thyroidectomy followed by an autotransplantation of the parathyroid glands and further by infusion of calcitonin. These studies demonstrated unchanged concentrations of renal calbindin-D28k. It was concluded that the increased calcium reabsorption induced by calcitonin in the distal tubule is not mediated by calbindin-D28k. Urinary calcium excretion is in part regulated by the action of PTH on calcium reabsorption in the distal nephron. Previous reports of increased expression of renal calbindin-D28k in uremic rats led us to suggest that secondary hyperparathyroidism associated with uremia induced the synthesis of renal calbindin-D28k. Therefore, the effect of PTH was examined in a study comprising selective parathyroidectomy and infusions of PTH, PTHrP, 1,25-(OH)2D and calcium. (ABSTRACT TRUNCATED)
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PMID:Regulation of renal calbindin-D28K. 1109 7

Calcium supplementation is effective in reducing blood pressure in various states of hypertension, including pregnancy-induced hypertension and preeclampsia. In addition, calcitropic hormones are associated with blood pressure. The hypothesis is that short-term therapy with calcium and vitamin D(3) may improve blood pressure as well as secondary hyperparathyroidism more effectively than calcium monotherapy. The effects of 8 weeks of supplementation with vitamin D(3) (cholecalciferol) and calcium on blood pressure and biochemical measures of bone metabolism were studied. The sample consisted of 148 women (mean +/- SD age, 74 +/- 1 yr) with a 25-hydroxycholecalciferol (25OHD(3)) level below 50 nmol/L. They received either 1200 mg calcium plus 800 IU vitamin D(3) or 1200 mg calcium/day. We measured intact PTH, 25OHD(3), 1,25-dihydroxyvitamin D(3), blood pressure, and heart rate before and after treatment. Compared with calcium, supplementation with vitamin D(3) and calcium resulted in an increase in serum 25OHD(3) of 72% (P < 0.01), a decrease in serum PTH of 17% (P = 0.04), a decrease in systolic blood pressure (SBP) of 9.3% (P = 0.02), and a decrease in heart rate of 5.4% (P = 0.02). Sixty subjects (81%) in the vitamin D(3) and calcium group compared with 35 (47%) subjects in the calcium group showed a decrease in SBP of 5 mm Hg or more (P = 0.04). No statistically significant difference was observed in the diastolic blood pressures of the calcium-treated and calcium- plus vitamin D(3)-treated groups (P = 0.10). Pearson coefficients of correlation between the change in PTH and the change in SBP were 0.49 (P < 0.01) for the vitamin D(3) plus calcium group and 0.23 (P < 0.01) for the calcium group. A short-term supplementation with vitamin D(3) and calcium is more effective in reducing SBP than calcium alone. Inadequate vitamin D(3) and calcium intake could play a contributory role in the pathogenesis and progression of hypertension and cardiovascular disease in elderly women.
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PMID:Effects of a short-term vitamin D(3) and calcium supplementation on blood pressure and parathyroid hormone levels in elderly women. 1129 96

Cyclosporine A (CsA) is a potent immunosuppressive agent widely used to prevent allograft rejection. In vivo administration of CsA is associated with the development of high-turnover osteopenia. Endothelin-1 (ET), a vasoconstrictive peptide, has been implicated in CsA-induced nephrotoxicity and hypertension. Recent evidence suggests that endothelin plays a pivotal role in bone metabolism. The present study was designed to investigate whether L-754,142 (ETRA), the combined endothelin A and B receptor antagonist, when given to rats, would favorably modify the bone loss caused by CsA. Fifty, 5-month-old male Sprague-Dawley rats were randomly divided into five groups of 10 rats each. The first group served as a basal control. The remaining four groups received, by daily gavage for 28 days, (1) a combined CsA and ETRA vehicle, (2) CsA, 10 mg/kg, (3) ETRA, 30 mg/kg, and (4) CsA, 10 mg/kg and ETRA, 30 mg/kg, respectively. Rats were weighed and venous blood was collected on days 0, 14, 28 for determination of BUN, creatinine, calcium, PTH, osteocalcin, and 1,25(OH)2 D. Tibiae, after double labeling, were removed following sacrifice for histomorphometry. Both CsA-treated rats and CsA/ETRA-treated rats demonstrated trabecular osteopenia with raised serum osteocalcin, and 1,25(OH)2D levels when compared to control animals (P < 0.05). Rats given CsA alone developed renal impairment, as shown by an increased BUN. The combination group did not develop renal impairment. The results suggest that endothelin may contribute to the development of CsA-induced nephrotoxicity, which was prevented by ETRA, but does not seem to play a role in CsA-induced osteopenia.
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PMID:The endothelin receptor antagonist, L-754,142 does not prevent cyclosporine A-induced osteopenia in rats. 1131 Mar 47

To evaluate the long-term results of parathyroidectomy (PTX) on parathyroid function, blood pressure and anemia, data of 45 patients with secondary Hyperparathyroidism in dialysis who had undergone PTX were collected retrospectively from 8 different dialysis units. The patients, 25 M and 20 F, mean age 56 +/- 11 years, who were followed up for an average period of 3.3 +/- 2.3 years, were divided into four groups according to the surgical procedure: 19 patients had had a subtotal PTX; 10 patients had undergone total PTX with autotransplantation (AT); 10 patients had had total PTX without AT, and 6 patients had undergone partial PTX. Taking a reduction in intact PTH > 50% as sign of successful PTX, only 5 patients did not attain this result. Considering values of PTH between 20 and 200 pg/ml at the mid-term observation (1-2 years) as the optimal result, values under 20 pg/ml as an expression of permanent hypoparathyroidism, and those above 200 pg/ml as indicating persistent/recurrent hyperparathyroidism, 65.5% of patients operated with subtotal PTX and total PTX + AT had a therapeutic success, versus 31.2% of patients in the other two groups, due to excess permanent hypoparathyroidism and persistent/recurrent hyperparathyroidism; 20 of 45 patients with preoperative hypertension experienced a statistically and clinically significant decrease in blood pressure levels. An increase in serum hemoglobin was also observed, despite a reduction of administered erythropoietin. In conclusion, the results of PTX obtained from this multicenter study are comparable to those reported by single leading centers. Recommended surgical procedures are subtotal PTX and total PTX with AT. The fall in blood pressure in hypertensive patients is clinically significant, and improvement in anemia is also observed with a reduction in erythropoietin dosage.
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PMID:Parathyroidectomy in chronic renal failure: short- and long-term results on parathyroid function, blood pressure and anemia. 1139 18

Glucagon binding to hepatocytes has been known for a long time to not only stimulate intracellular cAMP accumulation but also, intriguingly, induce a significant release of liver-borne cAMP in the blood. Recent experiments have shown that the well-documented but ill-understood natriuretic and phosphaturic actions of glucagon are actually mediated by this extracellular cAMP, which inhibits the reabsorption of sodium and phosphate in the renal proximal tubule. The existence of this "pancreato-hepatorenal cascade" indicates that proximal tubular reabsorption is permanently influenced by extracellular cAMP, the concentration of which is most probably largely dependent on the insulin-to-glucagon ratio. The possibility that renal cAMP receptors may be involved in this process is supported by the fact that cAMP has been shown to bind to brush-border membrane vesicles. In other cell types (i.e., adipocytes, erythrocytes, glial cells, cardiomyocytes), cAMP eggress and/or cAMP binding have also been shown to occur, suggesting additional paracrine effects of this nucleotide. Although not yet identified in mammals, cAMP receptors (cARs) are already well characterized in lower eukaryotes. The amoeba Dictyostelium discoideum expresses four different cARs during its development into a multicellular organism. cARs belong to the superfamily of seven transmembrane domain G protein-coupled receptors and exhibit a modest homology with the secretin receptor family (which includes PTH receptors). However, the existence of specific cAMP receptors in mammals remains to be demonstrated. Disturbances in the pancreato-hepatorenal cascade provide an adequate pathophysiological understanding of several unexplained observations, including the association of hyperinsulinemia and hypertension, the hepatorenal syndrome, and the hyperfiltration of diabetes mellitus. The observations reviewed in this paper show that cAMP should no longer be regarded only as an intracellular second messenger but also as a first messenger responsible for coordinated hepatorenal functions, and possibly for paracrine regulations in several other tissues.
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PMID:Extracellular cAMP inhibits proximal reabsorption: are plasma membrane cAMP receptors involved? 1183 18

A rare case of von Hippel-Lindau (VHL) disease with bilateral pheochromocytomas, right renal cell carcinoma, right pelvic carcinoma, spinal hemangioblastoma and primary hyperparathyroidism is described. A 78-year-old woman had a history of hypertension from her forties. She suffered from headache and body weight loss. Abdominal CT revealed bilateral adrenal tumors and right external renal tumors enhanced in early stage. MIBG scintigraphy exhibited a high accumulation of tracer in both adrenal glands. On the basis of the radiographic findings and endocrinological results, the patient was diagnosed as having bilateral pheochromocytomas and right renal cell carcinoma. A bilateral adrenectomy was performed, followed by surgery for resection of the renal cell carcinoma. The other resected right kidney showed a clear cell subtype that was determined to be renal cell carcinoma, and proved that the pelvic tumor was transient cell carcinoma. Spinal MRI showed spinal hemangioblastoma. von Hippel-Lindau (VHL) gene mutation for the patient was found. We diagnosed the patient as VHL because of the existence of spinal hemangioma and a VHL disease gene. Parathyroid echo revealed a hypoechoic space on the back of the left lobe, and serum calcium and intact PTH to be elevated. The patient was diagnosed as primary hyperparathyroidism. We report the first case of a patient with VHL disease complicated with bilateral pheochromocytomas, right renal cell carcinoma, right renal pelvic carcinoma and primary hyperparathyroidism. The life expectancy of affected individuals has been less than 50 years. Since the prognosis may be improved by an early diagnosis, affected individuals with VHL complexes should undergo cranial, spinal MRI and abdomen CT. The families may benefit from presymptomatic detection of affected gene carriers and the exclusion of at-risk family members by negative test results.
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PMID:A case of von Hippel-Lindau disease with bilateral pheochromocytoma, renal cell carcinoma, pelvic tumor, spinal hemangioblastoma and primary hyperparathyroidism. 1208 Dec 37

Patients with primary hyperparathyroidism (PHPT) have an increased cardiovascular morbidity and mortality. Elevated serum calcium and/or PTH may directly contribute to vascular tissue damage, but the role of classic factors for atherosclerosis has not fully been evaluated in this disease. The aim of our study was to dissect the potential effect of hypercalcemia and/or high PTH from that of major cardiovascular risk factors (i.e. diabetes mellitus, hyperlipidemia, hypertension, obesity, smoking habit) on the carotid artery structure of patients with PHPT. Twenty-six consecutive patients with PHPT [subdivided into two groups according to the absence (n = 10) or the presence (n = 16) of one or more risk factors] and 15 normocalcemic healthy subjects as controls were studied. At ultrasonography, a significant increase (P < 0.001) of carotid mean and maximum intima-media thickness, as well as a significant reduction of lumen diameter (P < 0.05) were found in the PHPT group with risk factors, compared with the other two groups. This suggests that hypercalcemia and/or PTH elevation per se are not determinant of carotid atherosclerosis in PHPT, and that increased cardiovascular mortality and morbility in this disease is attributable to the combined presence of classic cardiovascular risk factors.
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PMID:Ultrasound evaluation of carotid artery in primary hyperparathyroidism. 1272 60

Cardiovascular diseases connected with atherosclerosis are the main factor of morbidity and mortality in patients with end-stage renal failure. Hyperhomocysteinemia is a known and independent risk factor of atherosclerosis, occurring in 85-95% patients treated with hemodialysis. The aim of this study was to analyse relation between plasma level of homocysteine and chosen indicators of atherosclerosis development and also examined retrospectively cardiovascular complications in these patients. The study was carried out in 100 patients on hemodialysis who were divided into two groups: 72 patients with mild (20.74 mumol/l +/- 3.75) and 28 patients with moderate hyperhomocysteinemia (38.81 mumol/l +/- 9.81). Ultrasonographic examinations of Carotid Communis Artery Intima-Media Thickness (IMT), Ankle-Arm Blood Pressure Index (AABPI), echocardiographic parameters and biochemical examinations such as: PTH, folic acid and Vitamin B12, total protein, albumin, fibrinogen, glucose, total, LDL and HDL cholesterol, transferring, apolipoprotein B, lipoprotein (a), sodium potassium, calcium, phosphate, magnesium, iron, ferritin, urea, creatinine, uric acid and value of Hb, Ht, total iron binding capacity and transferring saturation, were performed. Patients with hypertension were divided into groups according to the number of taken anti-hypertensive drugs. Hyperhomocysteinemia was confirmed in 96% of patients. Frequency and type of acute cardiovascular complications were not related with the level of hyperhomocysteinemia. Statistically significant difference between IMT and level of hyperhomocysteinemia was observed. In patients with mild hyperhomocysteinemia IMT was 0.68 mm +/- 0.24 whereas in patients with moderate hyperhomocysteinemia 0.80 mm +/- 0.25, p < 0.036). Positive correlation between level of homocysteine and IMT (r = 0.22, p < 0.03) was noted. Based on this study, we concluded, that measurement of intima-media thickness is a good indicator of atherosclerosis development and correlates with hyperhomocysteinemia in patients on maintenance hemodialysis. It clearly confirms the role of hyperhomocysteinemia as significant risk factor of atherosclerosis in those patients.
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PMID:[Hyperhomocysteinemia and advancement of atherosclerosis in patients with chronic renal failure on maintenance hemodialysis]. 1273 67

Primary hyperparathyroidism (pHPT) has changed its clinical features in the last decade becoming a mild biochemical disease, in which the classical fibrous cystic osteitis is a rare complication. The more frequent bone involvement in primary hyperparathyroidism is observed at the distal 1/3 of the radius, where the cortical bone is primarily represented. However, lumbar and femoral osteopenia or osteoporosis prevalently affect hyperparathyroid post-menopausal women. We report two, otherwise healthy, young male patients, who presented a painful jaw swelling. In both patients standard radiographic imaging revealed a low-density well-defined lesion, which caused jaw bone destruction. High levels of serum calcium (14.1-16.6 mg/dl, n.v. 8.1-10.4) and PTH (1172-1928 pg/ml, n.v. 10-65) indicated the presence of pHPT associated with hypertension, asymptomatic renal involvement and osteoporosis with normal serum 25-hydroxyvitamin D levels in both patients. A single huge parathyroid adenoma was successfully removed and within 2 months jaw lesions were almost completely re-mineralized without any other therapeutic intervention in both patients. In conclusion, although brown jaw tumors are a rare complication of the hyperparathyroidism, they should be considered and identified in young patients with severe pHPT. Moreover, such a complication seems to be independent from vitamin D deficiency, suggesting the involvement of other pathogenetic factors.
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PMID:Brown jaw tumors: today's unusual presentation of primary hyperparathyroidism. 1459 21


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