Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0038187 (starvation)
 24,951 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects of total food deprivation on renal function were evaluated in normal Munich-Wistar rats submitted to starvation (S) periods of two to eight days (Groups S2 to S8). A prompt and sustained decrease in renal plasma flow (RPF) and an increase in total renal vascular resistance (TRVR) were observed after the second day, together with a gradual decrease in glomerular filtration rate (GFR) until the fourth day (40% in the S4 group, P less than 0.05). After this period, a spontaneous and progressive increase in GFR occurred in spite of continuing low RPF and high TRVR. Glomerular hemodynamics were evaluated in additional animals from groups S4 and S7. As observed for whole kidney GFR, mean single nephron (SN) GFR was reduced in group S4, but not in group S7. The decline in SNGFR in S4 was the result of a decline (approximately 40%) in glomerular plasma flow rate (QA) and glomerular capillary hydraulic pressure (PGC), due to a predominant increase (approximately 60%) in afferent arteriolar resistance. In S7, SNGFR and its determinants did not differ from the control. Angiotensin II (Ang II), prostaglandin (but not thromboxane A2, TxA2) inhibition blunted the alterations in whole kidney function observed in S4. Conversely in S7, the inhibition of vasoconstrictor agents (Ang II and TxA2) did not normalize GFR, suggesting that the intrarenal vasoconstriction could be an important factor to maintain GFR after a prolonged period of starvation.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Glomerular hemodynamics and hormonal evaluation during starvation in rats. 140 35

Patients with anorexia nervosa frequently demonstrate dehydration, electrolyte imbalance and low blood pressure that are secondary to starvation. Hyperactivity of the Renin-Aldosterone system and insensitivity to the pressor effects of exogenous angiotensin II are observed in Pseudo-Bartter syndrome caused by the abuse of diuretics or laxatives and self-induced vomiting, however, little information about the Renin-Aldosterone system has been reported in patients with anorexia nervosa. This study was designed to investigate the secretory function of the Renin-Aldosterone system in anorexia nervosa. The subjects were 13 patients with anorexia nervosa and 6 normal controls. Experiment 1: Angiotensin II infusion test was performed. Blood pressure was measured every 5 minutes, and the samples for plasma renin and serum aldosterone analysis were taken every 15 minutes during infusion test. Experiment 2: Plasma renin activity and serum aldosterone concentration were measured before and after one-hour walking. The results were as follows; (1) Basal plasma renin activity and serum aldosterone concentration in patients were not significantly higher than those in normal subjects. (2) Hypertensive response with elevation of the diastolic pressure during angiotensin II infusion in patients similar to that of normal subjects was observed. (3) Responses of plasma renin activity and serum aldosterone concentration after one-hour walking were significantly greater in patients than in normal subjects.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Secretory function of the renin-aldosterone system in patients with anorexia nervosa. 201 46

Angiotensin II type 2 (AT2) receptor is expressed abundantly in the fetal vasculature with rapid decline after birth and re-expressed in the adult vasculature after injury, whereas angiotensin II type 1 (AT1) receptor is expressed. We studied their effects on apoptosis in cultured rat vascular smooth muscle cells (VSMC). Serum starvation induced VSMC DNA fragmentation and the stimulation of AT1 receptor inhibited this apoptotic change. We transfected rat AT2 receptor cDNA, since cultured adult VSMCs show very low level of endogenous AT2 receptor. In AT2 receptor transfected VSMC, selective stimulation of AT2 receptor facilitated serum-deprivation-induced apoptosis and AT1 receptor stimulation inhibited it. Moreover we observed that AT1 receptor stimulation activated extracellular signal-regulated kinase (ERK), whereas the AT2 receptor stimulation inhibited the activation of ERK. Taken together, our results suggest that AT1 and AT2 receptors exert counteracting effects on ERK activation and consequently VSMC apoptosis and differential expression of these receptors may participate in vascular development and vascular remodeling.
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PMID:Angiotensin II type 2 receptor mediates vascular smooth muscle cell apoptosis and antagonizes angiotensin II type 1 receptor action: an in vitro gene transfer study. 980 32

Caveolin, a major protein component of caveolae, directly interacts with multiple signaling molecules, such as Ras and growth factor receptors, and inhibits their function. However, the role of the second messenger system in mediating this inhibition by caveolin remains poorly understood. We examined the role of Ca2+-dependent signal in caveolin- mediated growth inhibition using a rat cardiac myoblast cell line (H9C2), in which the expression of caveolin- 3, the muscle specific subtype, can be induced using the LacSwitch system. Upon induction with IPTG and serum-starvation, the expression of caveolin-3 was increased by 3.3-fold relative to that of mock-induced cells. The recombinant caveolin-3 was localized to the same subcellular fraction as endogenous caveolin-3 after sucrose gradient purification. Angiotensin II enhanced ERK phosphorylation, but this enhancement was significantly decreased in caveolin-3-induced cells in comparison to that in mock-induced cells. Similarly, when cells were stimulated with fetal calf serum, DNA synthesis, as determined by [3H]-thymidine incorporation, was significantly decreased in caveolin- 3-induced cells. When cells were treated with Ca2+ chelator (BAPTA and EGTA), however, this attenuation was blunted. Calphostin (PKC inhibitor), but not cyclosporine A treatment (calcineurin inhibitor), blunted this attenuation in caveolin-3 induced cells. Our findings suggest that caveolin exhibits growth inhibition in a Ca2+-dependent manner, most likely through PKC, in cardiac myoblasts.
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PMID:Caveolin-3 inhibits growth signal in cardiac myoblasts in a Ca2+-dependent manner. 1656 33

The serum- and glucocorticoid-inducible kinase 1 (SGK1) is known to regulate a wide variety of cellular processes, including renal sodium retention and cell survival. Angiotensin II (Ang II) is one of the many signaling molecules capable of regulating SGK1 expression, and is also known to impact cell survival. Here, we examined the role of SGK1 in Ang II-mediated cell survival. We hypothesized that Ang II protects cells from apoptosis by upregulating and activating SGK1. To test this, we examined the effects of Ang II stimulation on SGK1 expression and downstream signaling. We also examined the effects of Ang II treatment and siRNA-mediated SGK1 knockdown on apoptosis after serum starvation. We found that after 2h of Ang II treatment, SGK1 mRNA expression was increased approximately 2-fold. This induction was sensitive to reductions in intracellular calcium levels after pretreatment with BAPTA-AM, but insensitive to the L-type calcium channel blocker verapamil. SGK1 induction was also sensitive to the tyrosine kinase inhibitor genistein. Ang II treatment also caused a rapid increase in the level of phosphorylation of SGK1 at Ser422 and Thr256, and Ser422 phosphorylation was rapamycin-sensitive. We found that Ang II treatment was protective against serum starvation-induced apoptosis, and this protective effect was significantly blunted when SGK1 was silenced via siRNA. Lastly, Ang II induced FOXO3A phosphorylation in an SGK1-dependent manner, thereby reducing the pro-apoptotic actions of FOXO3A. Overall, these results indicate that Ang II upregulates and activates SGK1, leading to increased cell survival via multiple, non-redundant mechanisms.
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PMID:Angiotensin II mediates cell survival through upregulation and activation of the serum and glucocorticoid inducible kinase 1. 2196 29

Pathological cardiac hypertrophy is the main determinant of the development of heart failure, for which there is often no effective therapy. The dysregulation of autophagy is implicated in hypertrophy, but the mechanism linking these processes is unclear. In this study, we characterized the regulatory role of miR-208a-3p in autophagy in H9c2 cardiomyoblasts induced by Angiotensin II (Ang II). We found that miR-208a-3p was up-regulated in Ang II-induced H9c2 cardiomyoblasts and in starvation-induced autophagy. The overexpression of miR-208a-3p increased Ang II-induced autophagy, and this was accompanied by the inhibition of programmed cell death protein (PDCD4) and upregulation of autophagy protein 5 (ATG5). A dual-luciferase report assay confirmed the direct binding between miR-208a-3p and PDCD4. PDCD4 knockdown up-regulated autophagy, and its overexpression down-regulated this process. Moreover, the PDCD4-mediated regulation of autophagy was modulated by ATG5. Taken together, these findings indicate that miR-208a-3p promotes autophagy during Ang II-induced hypertrophy and provide a basis for the development of therapies for hypertrophic-induced cardiac dysfunction.
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PMID:MiR-208a-3p aggravates autophagy through the PDCD4-ATG5 pathway in Ang II-induced H9c2 cardiomyoblasts. 2924 Oct 69

The angiotensin-converting enzyme (ACE) is a peptidase that is involved in the synthesis of Angiotensin II, the bioactive component of the renin-angiotensin system. A growing body of literature argues for a beneficial impact of ACE inhibitors (ACEi) on age-associated metabolic disorders, mediated by cellular changes in reactive oxygen species (ROS) that improve mitochondrial function. Yet, our understanding of the relationship between ACEi therapy and metabolic parameters is limited. Here, we used three genetically diverse strains of Drosophila melanogaster to show that Lisinopril treatment reduces thoracic ROS levels and mitochondrial respiration in young flies, and increases mitochondrial content in middle-aged flies. Using untargeted metabolomics analysis, we also showed that Lisinopril perturbs the thoracic metabolic network structure by affecting metabolic pathways involved in glycogen degradation, glycolysis, and mevalonate metabolism. The Lisinopril-induced effects on mitochondrial and metabolic parameters, however, are genotype-specific and likely reflect the drug's impact on nutrient-dependent fitness traits. Accordingly, we found that Lisinopril negatively affects survival under nutrient starvation, an effect that can be blunted by genotype and age in a manner that partially mirrors the drug-induced changes in mitochondrial respiration. In conclusion, our results provide novel and important insights into the role of ACEi in cellular metabolism.
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PMID:Age- and Genotype-Specific Effects of the Angiotensin-Converting Enzyme Inhibitor Lisinopril on Mitochondrial and Metabolic Parameters in Drosophila melanogaster. 3037 67