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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Obesity and its related disorders are the most prevalent health problems in the Western world. Using the paradigm of fetal programming we developed a rodent model which displays the phenotype of obesity and metabolic disorders commonly observed in human populations. We apply maternal undernutrition throughout gestation, generating a nutrient-deprived intrauterine environment to induce fetal programming. Maternal undernutrition results in fetal growth retardation and in significantly decreased body weight at birth. Programmed offspring develop hyperphagia, obesity, hypertension, hyperleptinemia and hyperinsulinism during adult life and postnatal hypercaloric nutrition amplifies the metabolic abnormalities induced by fetal programming. The adipoinsular axis has been proposed as a primary candidate for linking the status of body fat mass to the function of the pancreatic beta-cells. We therefore investigated the relationship between circulating plasma concentrations of leptin and insulin and immunoreactivity in the endocrine pancreas for leptin and leptin receptor (OB-R) in genetically normal rats that were programmed to become obese during adult life. Virgin Wistar rats were time mated and randomly assigned to receive food either available ad libitum (AD group) or at 30% of the ad libitum available intake (UN group). Offspring from UN mothers were significantly smaller at birth than AD offspring (AD 6.13+/-0.04 g, UN 4.02+/-0.03 g, P<0.001). At weaning, offspring were assigned to one of two diets (a standard control diet or a hypercaloric diet consisting of 30% fat) for the remainder of the study. At the time of death (125 days of age), UN offspring had elevated (P<0.005) fasting plasma insulin (AD control 1.417+/-0.15 ng/ml, UN control 2.493+/-0.33 ng/ml, AD hypercaloric 1.70+/-0.17 ng/ml, UN hypercaloric 2.608+/-0.41 ng/ml) and leptin (AD control 8.8+/-1.6 ng/ml, UN control 14.32+/-1.9 ng/ml, AD hypercaloric 15.11+/-1.8 ng/ml, UN hypercaloric 30.18+/-5.3 ng/ml) concentrations, which were further increased (P<0.05) by postnatal hypercaloric nutrition. The elevated plasma insulin and leptin concentrations were paralleled by increased immunolabeling for leptin in the peripheral cells of the pancreatic islets. Dual immunofluorescence histochemistry for somatostatin and leptin revealed that leptin was co-localized in the pancreatic delta-cells. OB-R immunoreactivity was evenly distributed throughout the pancreatic islets and was not changed by programming nor hypercaloric nutrition. Our data suggest that reduced substrate supply during fetal development can trigger permanent dysregulation of the adipoinsular feedback system leading to hyperleptinemia, hyperinsulinism and compensatory leptin production by pancreatic delta-cells in a further attempt to reduce insulin hypersecretion in the progression to adipogenic diabetes.
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PMID:Dysregulation of the adipoinsular axis -- a mechanism for the pathogenesis of hyperleptinemia and adipogenic diabetes induced by fetal programming. 1147 29

Elevated plasma angiotensinogen (AGT) levels have been demonstrated in insulin-resistant states such as obesity and type 2 diabetes mellitus (DM2), conditions that are directly correlated to hypertension. We examined whether hyperinsulinemia or hyperglycemia may modulate fat and liver AGT gene expression and whether obesity and insulin resistance are associated with abnormal AGT regulation. In addition, because the hexosamine biosynthetic pathway is considered to function as a biochemical sensor of intracellular nutrient availability, we hypothesized that activation of this pathway would acutely mediate in vivo the induction of AGT gene expression in fat and liver. We studied chronically catheterized lean (approximately 300 g) and obese (approximately 450 g) Sprague-Dawley rats in four clamp studies (n = 3/group), creating physiological hyperinsulinemia (approximately 60 microU/ml, by an insulin clamp), hyperglycemia (approximately 18 mM, by a pancreatic clamp using somatostatin to prevent endogenous insulin secretion), or euglycemia with glucosamine infusion (GlcN; 30 micromol. kg(-1). min(-1)) and equivalent saline infusions (as a control). Although insulin infusion suppressed AGT gene expression in fat and liver of lean rats, the obese rats demonstrated resistance to this effect of insulin. In contrast, hyperglycemia at basal insulin levels activated AGT gene expression in fat and liver by approximately threefold in both lean and obese rats (P < 0.001). Finally, GlcN infusion simulated the effects of hyperglycemia on fat and liver AGT gene expression (2-fold increase, P < 0.001). Our results support the hypothesis that physiological nutrient "pulses" may acutely induce AGT gene expression in both adipose tissue and liver through the activation of the hexosamine biosynthetic pathway. Resistance to the suppressive effect of insulin on AGT expression in obese rats may potentiate the effect of nutrients on AGT gene expression. We propose that increased AGT gene expression and possibly its production may provide another link between obesity/insulin resistance and hypertension.
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PMID:Hyperglycemia modulates angiotensinogen gene expression. 1150 94

A 35-year-old woman was admitted to our hospital with the following complaints, headache, sweating, anxiety, dizziness, nausea, vomiting and severe hypertension. The technical images (abdominal CT, scintigraphic octreotide scan and renal arteriography) revealed the presence of a left adrenal pheochromocytoma and stenosis of the renal artery. Ten days following adrenalectomy, watery diarrhea appeared. The long-acting somatostatin analogue octreotide (LAR, 30 mg/month, i.m.), was started, and after 2 weeks diarrhea decreased and gradually disappeared. In conclusion, we were confronted with an unusual case of pheochromocytoma associated with renal artery stenosis and the appearance of watery diarrhea some days after surgical treatment. Treatment with octreotide brought about the remission of diarrhea in this patient.
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PMID:A case of pheochromocytoma with renal artery stenosis and post-surgical watery diarrhea. 1184 76

The stress system coordinates the adaptive responses of the organism to stressors of any kind.(1). The main components of the stress system are the corticotropin-releasing hormone (CRH) and locus ceruleus-norepinephrine (LC/NE)-autonomic systems and their peripheral effectors, the pituitary-adrenal axis, and the limbs of the autonomic system. Activation of the stress system leads to behavioral and peripheral changes that improve the ability of the organism to adjust homeostasis and increase its chances for survival. The CRH and LC/NE systems stimulate arousal and attention, as well as the mesocorticolimbic dopaminergic system, which is involved in anticipatory and reward phenomena, and the hypothalamic beta-endorphin system, which suppresses pain sensation and, hence, increases analgesia. CRH inhibits appetite and activates thermogenesis via the catecholaminergic system. Also, reciprocal interactions exist between the amygdala and the hippocampus and the stress system, which stimulates these elements and is regulated by them. CRH plays an important role in inhibiting GnRH secretion during stress, while, via somatostatin, it also inhibits GH, TRH and TSH secretion, suppressing, thus, the reproductive, growth and thyroid functions. Interestingly, all three of these functions receive and depend on positive catecholaminergic input. The end-hormones of the hypothalamic-pituitary-adrenal (HPA) axis, glucocorticoids, on the other hand, have multiple roles. They simultaneously inhibit the CRH, LC/NE and beta-endorphin systems and stimulate the mesocorticolimbic dopaminergic system and the CRH peptidergic central nucleus of the amygdala. In addition, they directly inhibit pituitary gonadotropin, GH and TSH secretion, render the target tissues of sex steroids and growth factors resistant to these substances and suppress the 5' deiodinase, which converts the relatively inactive tetraiodothyronine (T(4)) to triiodothyronine (T(3)), contributing further to the suppression of reproductive, growth and thyroid functions. They also have direct as well as insulin-mediated effects on adipose tissue, ultimately promoting visceral adiposity, insulin resistance, dyslipidemia and hypertension (metabolic syndrome X) and direct effects on the bone, causing "low turnover" osteoporosis. Central CRH, via glucocorticoids and catecholamines, inhibits the inflammatory reaction, while directly secreted by peripheral nerves CRH stimulates local inflammation (immune CRH). CRH antagonists may be useful in human pathologic states, such as melancholic depression and chronic anxiety, associated with chronic hyperactivity of the stress system, along with predictable behavioral, neuroendocrine, metabolic and immune changes, based on the interrelations outlined above. Conversely, potentiators of CRH secretion/action may be useful to treat atypical depression, postpartum depression and the fibromyalgia/chronic fatigue syndromes, all characterized by low HPA axis and LC/NE activity, fatigue, depressive symptomatology, hyperalgesia and increased immune/inflammatory responses to stimuli.
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PMID:Hypothalamic-pituitary-adrenal axis, neuroendocrine factors and stress. 1237 95

Acromegaly is a chronic disorder invariably caused by a growth hormone (GH)-secreting pituitary tumour and is characterised by disabling symptoms (sweating, arthralgia, headache, paraesthesiae, fatigue), significant comorbidities (diabetes mellitus, hypertension, sleep apnoea), and premature mortality. Symptomatic control can be achieved by lowering insulin-like growth factor-I (IGF-I) concentrations to within the age-adjusted normal range, and survival can be improved to match that of the general population. However, even with optimal surgery and current medical therapies (dopamine agonists, somatostatin analogues), 30% to 50% of patients do not achieve target concentrations of IGF-I and GH. Pegvisomant is a new GH-receptor antagonist that blocks GH activity by inhibiting functional dimerisation of GH-receptors. Given as subcutaneous injections at dosages of 10 mg, 15 mg, or 20 mg/day for 3 Months, pegvisomant normalised serum IGF-I concentrations in, respectively, 54%, 81%, and 89% of acromegalic patients. Moreover, long-term pegvisomant therapy normalised IGF-I concentrations in 97% of patients treated for 12 Months or longer, with no evidence of tachyphylaxis. Pegvisomant is the most effective medical therapy, reported to date, in terms of normalisation of circulating IGF-I concentrations. In addition, pegvisomant appears to be safe and well tolerated. Although additional long-term studies are required to further assess safety, the introduction of this innovative treatment should allow for optimal disease control in patients with acromegaly.
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PMID:Pegvisomant: an advance in clinical efficacy in acromegaly. 1267 Feb 98

A 52-yr-old woman presented with hypertension, elevated urinary vanillylmandelic acid, metanephrines, normetanephrines, and plasma chromogranin A (CgA), but normal urinary catecholamine levels. Abdominal ultrasonography and subsequent MRI imaging showed a 3 cm nodular lesion of the right adrenal gland also visualized by 123I-meta-iodobenzylguanidine scintigraphy consistent with a pheochromocytoma (PC). Her OctreoScan was negative. The patient underwent right adrenalectomy and histological examination showed a PC. The adrenal medulla tissue was examined for somatostatin (SRIH) receptor subtypes 1 to 5 (SSTR1 to 5) expression by RT-PCR. Cultured tumor cells were treated with either SRIH, Lanreotide (Lan), or an SSTR2 (BIM-23 120) or SSTR5 (BIM-23 206) selective agonist. CgA secretion was measured in the medium by ELISA and catecholamine levels by HPLC after 6h. Cell viability was assessed after 48h. RT-PCR analysis showed that SSTR1, 2, 3 and 4 were expressed. CgA secretion was significantly reduced by SRIH (- 80 %), Lan (- 35 %), and the SSTR2 selective agonist (- 65 %). Norepinephrine secretion was reduced by SRIH (- 66 %), Lan (- 40 %), and BIM-23 120 (- 70 %). Epinephrine and dopamine secretion was also inhibited by treatment with SRIH (- 90 % and - 93 %, respectively) and BIM-23 120 (- 33 % and - 75 %, respectively) but not by Lan. Cell viability was also significantly reduced by SRIH (- 30 %), Lan (- 10 %), and the SSTR2 selective agonist (- 20 %). The SSTR5 selective agonist did not modify either CgA and catecholamine secretion or cell viability. Our data show that SSTRs may be present in a PC although OctreoScan is negative in vivo, and that SRIH and its analogs may reduce both differentiated and proliferative functions in chromaffin cells in vitro. These findings suggest that SRIH analogs with enhanced SSTR2 affinity might be useful in the medical therapy of PC, even when an OctreoScan is negative.
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PMID:An in vivo OctreoScan-negative adrenal pheochromocytoma expresses somatostatin receptors and responds to somatostatin analogs treatment in vitro. 1292 Jun 56

Pheochromocytoma is a rare tumor, but it represents a potentially curable form of hypertension. In patients with inherited pheochromocytoma, benign and bilateral tumors are more common. The diagnosis of pheochromocytoma rests in biochemical confirmation of catecholamine excess. Plasma-free metanephrine levels are arguably the most sensitive and specific test for the biochemical diagnosis of pheochromocytoma in high-risk patient populations. A timed 24-hour urine collection for total catecholamines and metabolic products (eg, vanillylmandelic acid and metanephrines) is the favored confirmatory test. Localization is most commonly accomplished with high-resolution computed tomography imaging, but magnetic resonance imaging can also be used. If both of these imaging modalities are nonlocalizing or equivocal, then radiolabeled meta-iodobenzylguanidine or somatostatin can be used to identify an adrenal or extra-adrenal tumor (paraganglioma). These imaging modalities can be used in the evaluation of patients with suspected or confirmed recurrent or metastatic disease. Systemic therapies for the treatment of patients with recurrent or metastatic disease have been disappointing. Radiation therapy is best applied for palliative relief of pain associated with bony metastases. In the absence of radiographic evidence for local tumor invasion, laparoscopic resection of small- to medium-sized (< 6 cm) pheochromocytomas is indicated. Abundant evidence indicates that this approach is safe and well tolerated and results in more rapid recovery and less long-term wound morbidity compared to open anterior or posterior adrenalectomy. Open anterior adrenalectomy is appropriate for patients with large or recurrent tumors, suspected or documented locoregional invasion, or for those patients in whom a laparoscopic approach is technically contraindicated. For selected patients with pheochromocytoma in the von Hipple-Lindau syndrome or multiple endocrine neoplasia type 2 setting in which the cumulative incidence of clinical bilateral tumors is high, a cortical-sparing approach may minimize the risk of Addisonian complications.
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PMID:Pheochromocytoma. 1294 13

Paragangliomas of the head and neck are uncommon neoplasms. They are usually benign, but tend to be locally invasive. Although surgical resection remains the definitive treatment, important issues about management arise when such lesions are inoperable. Beneficial effects of octreotide treatment have already been reported in a malign paraganglioma case. Here we report a 24 year old female with familial, bilateral, multiple paraganglioma in the head and neck region, who firstly presented with pulsatile tinnitus and hearing loss in her left ear. After embolization was performed, she underwent operation twice because of the gross tumor mass. No significant change in tumor size was determined after the operations, however there were no distant metastases. Although she experienced hypertension attacks, no hormonal overproduction was found in repeated measurements. As the tumor was unresectable, new alternative therapies were sought. Octreotide scintigraphy was positive in the tumoral tissue, so we began to treat her with somatostatin analogue octreotide. After a 16 month follow up period, an improvement of the performance status, the near normalisation of attacks and stabilization of tumor growth were achieved. However, in the last three visits, she began to experience symptoms more frequently and it had been necessary to increase the octreotide dose. She is now well and being followed up. In conclusion, the beneficial effects of octreotide treatment could be quantified by clinical, tumor and scintigraphic criteria. These data suggest that octreotide can be useful in the treatment of inoperable paragangliomas.
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PMID:Case report: patient with multiple paragangliomas treated with long acting somatostatin analogue. 1461 6

Acutely increased intra-abdominal pressure (IAP) may lead to abdominal compartment syndrome (ACS), which ischaemia/reperfusion (I/R) injury plays an important role. The main goal of the management of ACS is to lower the intra-abdominal pressure despite reperfusion injury. Octreotide (OCT), a synthetic somatostatin analogue, lowers the splanchnic perfusion. The aim of this study was to investigate whether OCT improves the reperfusion injury after decompression of acute abdominal hypertension.Under anesthesia, a catheter was inserted intraperitoneally and using an aneroid manometer connected to the catheter, IAP was kept at 20 mmHg (ischemia group; I) for 1h. In the I/R group, pressure applied for an hour was decompressed and 1h reperfusion period was allowed. In another group of I/R, OCT was administered (50 microg/kg i.p.) immediately before the decompression of IAP. The results demonstrate that kidney and lung tissues of malondialdehyde (MDA; an end product of lipid peroxidation) levels and myeloperoxidase (MPO; index of tissue neutrophil infiltration) activity were elevated, while glutathione (GSH; a key to antioxidant) levels were reduced in I/R group (P<0.001). Moreover, OCT treatment applied in the I/R group reduced the elevations in blood urea nitrogen (BUN) and serum creatinine levels. Our results implicate that IAP causes oxidative organ damage and OCT, by reducing splanchnic perfusion and controlling the reperfusion of abdominal organs, could improve the reperfusion-induced oxidative damage. Therefore, its therapeutic role as a "reperfusion injury-limiting" agent must be further elucidated in IAP-induced abdominal organ injury.
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PMID:Octreotide: a new approach to the management of acute abdominal hypertension. 1470 53

Ischemia/reperfusion injury plays an important role in the pathogenesis of abdominal compartment syndrome, which is characterized by increased intra-abdominal pressure. The aim of this study was to investigate whether octreotide, a synthetic somatostatin analogue, improves the reperfusion injury after decompression of acute abdominal hypertension. This study was carried out in Wistar albino rats. With the rats under anesthesia, an arterial catheter was inserted intraperioneally and with the use of an aneroid manometer connected to the catheter, intra-abdominal pressure was kept at 20 mm Hg (ischemia group) for 1 hour. In the ischemia/reperfusion group, pressure applied for 1 hour was decompressed and a 1-hour reperfusion period was allowed. In another ischemia/reperfusion group, octreotide was administered (50 microg/kg intraperitoneally) immediately before the decompression of intra-abdominal pressure. At the end of the experiment, liver and intestinal tissues were taken and malondialdehyde (an index of lipid peroxidation) and glutathione (a key to antioxidant) levels and myeloperoxidase (an index of tissue neutrophil infiltration) activity were estimated. The results demonstrated that tissue levels of malondialdehyde and myeloperoxidase activity were elevated, whereas glutathione levels were reduced in both the ischemia and ischemia/reperfusion groups. Octreotide treatment reversed these oxidant responses. In conclusion, increased intra-abdominal pressure causes oxidative organ damage and octreotide, by controlling the reperfusion of abdominal organs and inhibiting neutrophil infiltration, could improve the reperfusion-induced oxidative damage. Therefore its therapeutic role as a "reperfusion injury-limiting" agent must be further elucidated in intra-aortic pressure-induced abdominal organ injury.
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PMID:Octreotide improves reperfusion-induced oxidative injury in acute abdominal hypertension in rats. 1474 43


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