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You searched for subject:(Acid labile subunit). Showing records 1 – 3 of 3 total matches.

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Swedish University of Agricultural Sciences

1. Strage, Emma. Insulin-like growth factor-I in the domestic cat.

Degree: 2015, Swedish University of Agricultural Sciences

Insulin-like growth factor-I (IGF-I) has growth promoting effects as well as insulin-like actions on metabolism. IGF-I associates with a family of six high affinity IGF-binding proteins (IGFBPs) and these interfere in immunoassays for IGF-I. The role of binding of IGF-I to IGFBP-3, together with a third protein (the acid-labile subunit), to form a high molecular mass ternary complex, is not known in cats. In adult humans the ternary complex is the dominant circulating form. The cat is a strict carnivore with different metabolism to other species, which may include differences in the IGF system. In clinical practice serum IGF-I is used routinely for screening for acromegaly in cats with diabetes mellitus (DM). The overall aim of this thesis was to determine factors regulating IGF-I concentrations in health and disease. Enzyme-linked immunosorbent assays for measuring feline IGF-I and insulin were validated. It is recommended that laboratories, in validating their assays, should be aware of position effects on assay plates and, for IGF-I assays, interference by circulating IGFBPs. For IGF-I, between animal variation was high (~65%) while within animal variation was considerable lower (~8%). These values for biological variation can now be used in interpreting clinical results after repeated sampling in screening for, and in the management of, acromegaly. IGF-I concentrations were related to the amount of the ternary complex in healthy and diabetic cats. The ternary complex was the dominating circulating form only in cats with high IGF-I concentrations. There was a wide range of IGF-I concentrations in both healthy and diabetic cats that was in part related to variation in weight. When using IGF-I as a screening tool for acromegaly in diabetic cats, glycaemic control should also be taken into consideration. IGF-I concentrations increased in response to insulin treatment and concentrations at 2-4 weeks were higher in cats that later went into remission. In conclusion, in contrast to adult humans, circulating IGF-binding forms vary across the wide range of IGF-I concentrations in the cat. It is recommended that reference intervals for healthy cats are developed, stratifying by weight. IGF-I shows promise as a predictive marker for remission in feline diabetes mellitus.

Subjects/Keywords: cats; insulin-like growth factor; growth; insulin; diabetes; pituitary gland; endocrine diseases; diagnosis; Acid-labile subunit; Acromegaly; Diabetes mellitus; Growth hormone; Insulin; Insulin-like growth factor binding proteins; Ternary complex

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Strage, E. (2015). Insulin-like growth factor-I in the domestic cat. (Doctoral Dissertation). Swedish University of Agricultural Sciences. Retrieved from https://pub.epsilon.slu.se/12810/

Chicago Manual of Style (16th Edition):

Strage, Emma. “Insulin-like growth factor-I in the domestic cat.” 2015. Doctoral Dissertation, Swedish University of Agricultural Sciences. Accessed March 04, 2021. https://pub.epsilon.slu.se/12810/.

MLA Handbook (7th Edition):

Strage, Emma. “Insulin-like growth factor-I in the domestic cat.” 2015. Web. 04 Mar 2021.

Vancouver:

Strage E. Insulin-like growth factor-I in the domestic cat. [Internet] [Doctoral dissertation]. Swedish University of Agricultural Sciences; 2015. [cited 2021 Mar 04]. Available from: https://pub.epsilon.slu.se/12810/.

Council of Science Editors:

Strage E. Insulin-like growth factor-I in the domestic cat. [Doctoral Dissertation]. Swedish University of Agricultural Sciences; 2015. Available from: https://pub.epsilon.slu.se/12810/


University of Saskatchewan

2. Hepp, Michael Emerson. Regulation of hepatic ALS and IGFBP-1 expression.

Degree: 2005, University of Saskatchewan

The insulin-like growth factor (IGF) system is composed of IGF, IGF binding proteins (IGFBP-1 to -10) and the acid labile subunit (ALS). IGF exists as two isoforms, IGF-I and IGF-II. IGF-I is the major circulatory form and is primarily secreted by the liver. It functions to regulate proliferation and differentiation in a number of different cell types and elicits an insulin-like metabolic effect. As well as being regulated at levels of transcription and translation, IGF-I activities are also regulated through formation of complexes in circulation. IGF complexes form as binary complexes, such as the IGFBP-1 complex, and ternary complexes containing IGF-I, IGFBP-3 and ALS. Binary and ternary IGF complexes function to maintain stable pools of bioactive IGF-I. They also function to increase IGF half-life and sequester IGF in the bloodstream. ALS and IGFBP-1 are well characterized and exist as 85 kDa and 32 kDa proteins, respectively. They are expressed primarily in liver hepatocytes. Circulating ALS binds the IGF-I-IGFBP-3 complex and increases IGF half-life from 10 min in the IGFBP-3 binary complex to 10-15 hr in the ternary complex. IGFBP-1 binds IGF-I and increases the half-life from 10 min to 30 min. The ternary complex is the predominant IGF-I binding protein complex found in circulation. The IGFBP-1 complex represents only a small fraction of circulating IGF complexes. In this thesis ALS and IGFBP-1 regulation were investigated in terms of expression related to metabolic modulators and streptozotocin (STZ)-induced diabetes. Results from rat studies showed a decreased liver ALS gene expression in STZ-induced diabetic rats. STZ-treatment in rats mimics type-I diabetes with no change in secreted insulin with increase of circulatory glucose. The administration of insulin into the STZ-induced diabetic rats brought ALS levels to that of the untreated controls. ALS expression was positively regulated by insulin in H4IIE hepatoma cells. Growth hormone (GH), glucose, dexamethasone also positively regulated ALS gene expression while cAMP (2-b-cAMP) acted as a negative regulator in H4IIE cells. HepG2 cells expressing constitutively active protein kinase B (PKB) (HepG2-PKB-CA) increased ALS gene expression to levels 20% higher then parental HepG2. Insulin treatment of these cells unexpectedly increased ALS levels in both parental and PKB-CA HepG2. This may have indicated a partial regulatory role of the mitogen activated protein (MAP) kinase pathway as PKB was thought to be over-expressed therefore rendering the insulin signal redundant. Inhibition of the phosphoinositol-3 (PI-3) kinase and MAP kinase pathways through wortmannin and PD98059 incubation, respectively, suggested a possible interplay or crosstalk between the two pathways in insulin signaling. PKB is known to be activated through the PI-3 kinase pathway. Results suggested possibility that PKB may interact through the MAP kinase pathway in regulation of ALS gene expression. The activity of cAMP on ALS gene expression may occur through interaction with the PI-3… Advisors/Committee Members: Khandelwal, Ramji L., Laarveld, Bernard, Kulyk, William M., Angel, Joseph F., Roesler, William J..

Subjects/Keywords: Acid labile subunit; Insulin-like growth factor binding protein-1; Insulin-like growth factor

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Hepp, M. E. (2005). Regulation of hepatic ALS and IGFBP-1 expression. (Thesis). University of Saskatchewan. Retrieved from http://hdl.handle.net/10388/etd-06202005-162445

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Hepp, Michael Emerson. “Regulation of hepatic ALS and IGFBP-1 expression.” 2005. Thesis, University of Saskatchewan. Accessed March 04, 2021. http://hdl.handle.net/10388/etd-06202005-162445.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Hepp, Michael Emerson. “Regulation of hepatic ALS and IGFBP-1 expression.” 2005. Web. 04 Mar 2021.

Vancouver:

Hepp ME. Regulation of hepatic ALS and IGFBP-1 expression. [Internet] [Thesis]. University of Saskatchewan; 2005. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/10388/etd-06202005-162445.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Hepp ME. Regulation of hepatic ALS and IGFBP-1 expression. [Thesis]. University of Saskatchewan; 2005. Available from: http://hdl.handle.net/10388/etd-06202005-162445

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation


Virginia Tech

3. Wu, Miaozong. Nutritional Regulation of Serum Insulin-Like Growth Factor-I Concentration in Cattle.

Degree: PhD, Animal and Poultry Sciences, 2007, Virginia Tech

The overall objective of this dissertation research was to understand the mechanisms by which serum insulin-like growth factor-I (IGF-I) is regulated by nutritional intake in cattle. Two studies were conducted to achieve this objective. In the first study, effects of feeding levels on basal and growth hormone (GH)-stimulated serum concentrations of IGF-I, IGF binding protein-3 (IGFBP-3) and acid-labile subunit (ALS), and their mRNA expression in the liver were determined in beef cows. It was found that increased nutritional intake did not alter basal concentrations of serum IGF-I, IGFBP-3 or ALS, or their mRNA expression in the liver. However, under increased nutritional intake, GH administration stimulated a greater increase in serum IGF-I concentration, and this greater increase was not due to reduced degradation of IGF-I in serum. Increased nutritional intake did not enhance GH-stimulated IGF-I mRNA expression in the liver, but it increased the amount of IGF-I mRNA associated with polysomes, suggesting that liver translation of IGF-I mRNA is enhanced under increased nutritional intake. Under increased nutritional intake, GH also stimulated greater increases in serum IGFBP-3 and ALS concentrations, but these greater increases were not due to greater expression or translation of their mRNAs in the liver. Taken together, these results suggest that translation of GH-stimulated IGF-I mRNA in the liver is enhanced under increased nutritional intake and this enhancement may be partially responsible for the greater GH-stimulated increase in serum IGF-I concentration. These results also suggest that the greater GH-stimulated increases in serum IGFBP-3 and ALS may be secondary to the greater increase in serum IGF-I because increased IGF-I may increase the formation of IGF-I/IGFBP-3/ALS complexes, thereby increasing the retention of IGFBP-3 and ALS in the blood. In the second study, the effects of food deprivation on serum IGF-I concentration in steers and the underlying mechanism were determined. It was found that food deprivation decreased serum IGF-I concentration and that this decrease was not due to increased IGF-I degradation in serum. Food deprivation decreased liver IGF-I mRNA expression, and this decrease was associated with decreased expression of GH receptor (GHR) mRNA and protein in the liver. Food deprivation was also associated with increased mRNA expression of two inhibitors of the GHR signaling pathway, suppressor of cytokine signaling-2 (SOCS2) and cytokine-inducible SH2 protein (CIS). These results suggest that decreased IGF-I gene expression in the liver may be at least partially responsible for the decrease in circulating IGF-I concentration during food deprivation, and that the former decrease may be due to increased expression of SOCS2 and CIS, and decreased expression of GHR in the liver. Overall, this dissertation research indicates that multiple mechanisms are involved in nutritional regulation of circulating IGF-I concentration in cattle. Advisors/Committee Members: Jiang, Honglin (committeechair), Akers, Robert Michael (committee member), Hall, John B. (committee member), Liu, Dongmin (committee member), Webb, Kenneth E. Jr. (committee member).

Subjects/Keywords: Acid-labile subunit; Cattle; Insulin-like growth factor-I; Nutrition; IGF binding protein-3; Growth hormone

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Wu, M. (2007). Nutritional Regulation of Serum Insulin-Like Growth Factor-I Concentration in Cattle. (Doctoral Dissertation). Virginia Tech. Retrieved from http://hdl.handle.net/10919/28977

Chicago Manual of Style (16th Edition):

Wu, Miaozong. “Nutritional Regulation of Serum Insulin-Like Growth Factor-I Concentration in Cattle.” 2007. Doctoral Dissertation, Virginia Tech. Accessed March 04, 2021. http://hdl.handle.net/10919/28977.

MLA Handbook (7th Edition):

Wu, Miaozong. “Nutritional Regulation of Serum Insulin-Like Growth Factor-I Concentration in Cattle.” 2007. Web. 04 Mar 2021.

Vancouver:

Wu M. Nutritional Regulation of Serum Insulin-Like Growth Factor-I Concentration in Cattle. [Internet] [Doctoral dissertation]. Virginia Tech; 2007. [cited 2021 Mar 04]. Available from: http://hdl.handle.net/10919/28977.

Council of Science Editors:

Wu M. Nutritional Regulation of Serum Insulin-Like Growth Factor-I Concentration in Cattle. [Doctoral Dissertation]. Virginia Tech; 2007. Available from: http://hdl.handle.net/10919/28977

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