Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0028754 (obesity)
 124,988 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Obese hypertensive patients with cardiovascular risk factor clustering and increased risk for atherosclerotic disease have increased plasma nonesterified fatty acid levels, including oleic acid (OA), and a more active renin-angiotensin-aldosterone system. Vascular smooth muscle cell (VSMC) migration and proliferation participate in the development of atherosclerotic plaque. OA and angiotensin (Ang) II induce synergistic mitogenic responses in VSMCs through sequential signaling pathways dependent on the activation of protein kinase C (PKC), oxidants (reactive oxygen species, ROS), and extracellular signal-regulated kinase (ERK) activation. We tested the hypotheses that (1) OA and Ang II have additive or synergistic effects on VSMC migration and (2) PKC, ROS, and mitogen-activated protein kinase are critical signaling molecules. OA at 100 micromol/L increases VSMC migration 60+/-10% over control (P:<0.001). Ang II (10(-)(9) mol/L) increases VSMC migration by 62+/-13% and 73% over control, respectively (P:<0.01). Coincubation of cells with OA and Ang II produces a nearly additive increase in VSMC cell migration at 107+/-20% (P:<0.01). Increases in VSMC migration induced by OA alone and combined with Ang II were reduced by PKC inhibition and downregulation. VSMC migration in response to OA alone and with Ang II was also inhibited by N:-acetyl-cysteine, MEK inhibition, and ERK antisense. VSMC migration in response to OA alone or combined with Ang II is dependent on activation of PKC, ROS, and ERK activation, further raising the possibility that increased plasma nonesterified fatty acids and an activated renin-angiotensin-aldosterone system in subjects with the risk factor cluster contribute to accelerated atherosclerosis through a PKC, ROS, and ERK-dependent signaling pathway.
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PMID:Signaling events mediating the additive effects of oleic acid and angiotensin II on vascular smooth muscle cell migration. 1123 Feb 90

11beta-hydroxysteroid dehydrogenases (11beta-HSDs) catalyze the interconversion of active glucocorticoids (cortisol, corticosterone) and inert 11-keto forms (cortisone, 11-dehydrocorticosterone). 11beta-HSD type 2 has a well recognized function as a potent dehydrogenase that rapidly inactivates glucocorticoids, thus allowing aldosterone selective access to otherwise nonselective mineralocorticoid receptors in the distal nephron. In contrast, the function of 11beta-HSD type 1 has, until recently, been little understood. 11beta-HSD1 is an ostensibly reversible oxidoreductase in vitro, which is expressed in liver, adipose tissue, brain, lung, and other glucocorticoid target tissues. However, increasing data suggest that 11beta-HSD1 acts as a predominant 11beta-reductase in many intact cells, whole organs, and in vivo. This reaction direction locally regenerates active glucocorticoids within expressing cells, exploiting the substantial circulating levels of inert 11-keto steroids. While the biochemical determinants of the reaction direction are not fully understood, insights to its biological importance have been afforded by use of inhibitors in vivo, including in humans, and the generation of knockout mice. Such studies suggest 11beta-HSD1 effectively amplifies glucocorticoid action at least in the liver, adipose tissue, and the brain. Inhibition of 11beta-HSD1 represents a potential target for therapy of disorders that might be ameliorated by local reduction of glucocorticoid action, including type 2 diabetes, obesity, and age-related cognitive dysfunction.
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PMID:Minireview: 11beta-hydroxysteroid dehydrogenase type 1- a tissue-specific amplifier of glucocorticoid action. 1125 Sep 14

This review discusses the possible interrelationships between adrenal steroid hormones and the metabolic syndrome. Abnormal regulation of the hypothalamic-pituitary-adrenal axis has been proposed. Studies in the United Kingdom associated the metabolic syndrome with low birth weight and hyperactivity of the entire axis. In Italy, increased pituitary responsiveness to stimulation with vasopressin and corticotrophin-releasing hormone was demonstrated in women with central obesity. Swedish researchers have reported that increased stress responses of the axis correlated with a less variable but decreased cortisol level. An allele of the glucocorticoid receptor was also associated with various components of the metabolic syndrome. Evidence also suggests that central obesity is associated with an increased peripheral conversion of cortisol to cortisone and subsequent feedback stimulation of the axis. On the other hand, central fat may have an increased local metabolism in the direction of cortisol. Roles for dehydroepiandrosterone and aldosterone in the syndrome have also been proposed.
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PMID:The adrenal and the metabolic syndrome. 1127 91

Hypertension occurs more commonly in obese than in lean persons at virtually every age. A variety of endocrine, genetic, and metabolic mechanisms have been linked to the development of obesity hypertension. These include insulin resistance and hyperinsulinemia, increased serum aldosterone levels, salt sensitivity and expanded plasma volume in the presence of increased peripheral vascular resistance, a genetic predisposition, and possibly increased leptin levels. Pressure and volume overload are present in obese hypertensives. This leads to a mixed eccentric-concentric form of left ventricular hypertrophy and increases the predisposition to congestive heart failure. Weight loss, even in modest decrements, is effective in reducing obesity-hypertension, possibly by ameliorating several of the proposed pathophysiologic mechanisms. There are currently no specific recommendations concerning pharmacotherapy of obesity-hypertension because each drug group has pros and cons.
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PMID:Obesity, hypertension, and the heart. 1130 66

Excessive accumulation of adipose tissue is associated with profound alterations in the cardiovascular system. including an increase in systemic blood pressure. It now appears clear that a central feature of obesity-associated hypertension is related to changes in sodium handling that may result from abnormalities in sympathetic nervous system activity, the renin-angiotensin-aldosterone system, natriuretic peptides, and kidney function. In this paper we review the role of these factors in the development of obesity-associated hypertension, thereby focusing on the potential role of adipose tissue in these alterations.
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PMID:The renin-angiotensin system and natriuretic peptides in obesity-associated hypertension. 1132

With increasing case reports, it has been indicated that some cases with adrenocorticotropic hormone (ACTH)-independent macronodular adrenal hyperplasia (AIMAH) show abnormal responses in cortisol to various stimulation tests. Here we report a case of AIMAH that showed an aberrant response to angiotensin II via AT1 receptor in cortisol hypersecretion. A 53-yr-old man was admitted to our division seeking further examinations for the possible diagnosis of Cushing's syndrome. He had hypertension, diabetes mellitus, and physical stigmata, such as moon face and central obesity. His plasma ACTH level was undetectable, and plasma cortisol level was high. Plasma cortisol showed no normal diurnal rhythm and was not suppressed after the administration of 8 mg of dexamethasone. Abdominal computed tomography demonstrated nodular enlargement of bilateral adrenal glands. He was diagnosed with Cushing's syndrome owing to AIMAH. An injection of arginine vasopressin (AVP) increased plasma cortisol and aldosterone levels, whereas ACTH remained undetectable. After 4 h in an upright position, plasma cortisol and aldosterone levels were increased. Pretreatment with candesartan, angiotensin II receptor AT1 antagonist, blocked the increase in plasma cortisol level. These results suggested a possibility of adrenal hypersensitivity to angiotensin II and AVP in cortisol secretion. Bilateral laparoscopic adrenalectomy was performed. The histological findings of the specimen were compatible with AIMAH. In summary, we have made the first report on a case of AIMAH with possible hypersensitivity to angiotensin II.
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PMID:Case of adrenocorticotropic hormone-independent macronodular adrenal hyperplasia with possible adrenal hypersensitivity to angiotensin II. 1157 27

This article gives an overview, citing animal and clinical studies, of the effects of increased intra-abdominal pressure (IAP) in severe obesity. Animal studies demonstrate that increased IAP increases pleural pressure, cardiac filling pressures, femoral venous pressure, renal venous pressure, systemic blood pressure, and vascular resistance, renin and aldosterone levels, and intracranial pressure. Thus, the comorbidities presumed secondary to increased IAP in obese patients include congestive heart failure, hypoventilation, venous stasis ulcers, gastroesophageal reflux, urinary stress incontinence, incisional hernia, pseudotumor cerebri, proteinuria, and systemic hypertension.
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PMID:Effects of increased intra-abdominal pressure in severe obesity. 1158 45

The renin-angiotensin-aldosterone system (RAAS) plays a well-recognized role in the regulation of BP and in salt and water balance. Since hypertension affects a considerable proportion of obese patients, circulating RAAS has been studied in obese subjects with and without hypertension, albeit with conflicting results. Furthermore, attention has recently focused on the expression of the components of the Renin-angiotensin system (RAS) in some organs, including adipose tissue where it seems to be involved in the regulation of growth and differentiation. The aim of our study was to investigate circulating RAAS and adipose tissue RAS in obese patients with and without hypertension and in matched controls. PRA, and plasma and urinary aldosterone levels were measured in 35 obese, 30 hypertensive obese patients and in 20 controls. In addition, the expression of angiotensinogen (AGT) and angiotensin II type 1 receptor (AT1) genes was studied in sc adipose tissue from 8 obese, 6 hypertensive obese and 6 healthy subjects. As previously demonstrated in other studies, there were no significant differences in the levels of circulating RAAS components in the 3 groups. As regards local RAS, interestingly, we found that AT1 gene was significantly more expressed in sc adipose tissue from obese patients with hypertension than in those without hypertension and controls. By contrast, AGT levels were similar in the 3 groups. Our data do not support the hypothesis of an involvement of circulating RAAS in the development of obesity-related hypertension. On the other hand, local RAS seems to be differently regulated in sc adipose tissue from obese patients with hypertension with respect to normotensive obese patients and controls.
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PMID:Comparison of circulating and local adipose tissue renin-angiotensin system in normotensive and hypertensive obese subjects. 1203 Jun

There is growing evidence to the effect that steroid hormones are associated with a complex phenotype of metabolic abnormalities usually referred to as the metabolic syndrome. The 3 beta-hydroxysteroid dehydrogenases/Delta(4,5)-isomerase (3 beta-HSD) is crucial to the biosynthesis of hormonal steroids, including aldosterone, cortisol, and testosterone. The objective of the present study was to examine the potential impact of a T-->C substitution at codon Leu(338) of the type I (HSD3B1) 3 beta-HSD gene on obesity, circulating hormones, and estimates of insulin, glucose, and lipid metabolism as well as blood pressure in 284 unrelated Swedish men born in 1944. The subjects were genotyped by using PCR amplification of exon 4 of the HSD3B1 gene followed by digestion with the restriction enzyme BglII. The frequency of allele T was 0.44 and that of allele C 0.56. Homozygotes for the C allele (n=75) had significantly (P<0.05) higher mean systolic and diastolic blood pressures compared to both heterozygotes (n=143) and homozygotes for the T allele (n=45). In addition, the C allele was significantly (P=0.018) more frequent among subjects with grade 1 hypertension (>140/90 mm Hg) compared to normotensive (<130/85 mm Hg) subjects. These results were all adjusted for the potential confounding effect of body mass index (BMI) and waist-to-hip ratio (WHR). Other measurements such as BMI, WHR, abdominal sagittal diameter, salivary cortisol, total testosterone, serum leptin, fasting insulin and glucose, and serum lipids were not different across the HSD3B1 genotype groups. In conclusion, a T-->C polymorphism at codon Leu(338) of exon 4 of the HSD3B1 gene is associated with elevated systolic and diastolic blood pressures. The pathogenic mechanism underlying this association is, however, uncertain from the present data and further studies are warranted.
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PMID:Polymorphism in exon 4 of the human 3 beta-hydroxysteroid dehydrogenase type I gene (HSD3B1) and blood pressure. 1205 49

African Americans shoulder a disproportionately high burden of kidney disease when compared with white Americans. While environmental factors such as poverty and poor health habits, and the high prevalence of risk factors such as obesity, contribute to the high rate of kidney disease in this population, genetic factors may also contribute. Studies of polymorphisms in genes encoding the proteins of the renin-angiotensin-aldosterone system have identified alleles that are associated with kidney disease or changes in renal function in some populations. A higher prevalence of such alleles in African Americans may contribute to the increased prevalence of kidney disease. Diabetes mellitus and hypertension, the main causes of end-stage renal disease in the United States, are more prevalent in African Americans. However, no direct links between diabetic or hypertensive kidney disease and any genetic polymorphisms seen in African Americans have been identified. Further research is thus required to elucidate the genetic components that contribute to the high prevalence of kidney disease in African Americans.
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PMID:Kidney disease in African Americans: genetic considerations. 1215 8


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