Pituitary, analysis

Size Isomers. In solution, hGH is a mixture of monomer, dimer, and higher molecular weight oligomers. Furthermore, there are aggregated forms of hGH found in both the pituitary and in the circulation (16,17). The dimeric forms of hGH have been the most carefully studied and there appear to be at least three distinct types of dimer a disulfide dimer connected through interchain disulfide bonds (8) a covalent or irreversible dimer that is detected on sodium dodecylsulfate- (SDS-)polyacrylamide gels (see Electroseparations, Electrophoresis) and is not a disulfide dimer (19,20) and a noncovalent dimer which is easily dissociated into monomeric hGH by treatment with agents that dismpt hydrophobic interactions in proteins (21). In addition, hGH forms a dimeric complex with ( 2). Scatchard analysis has revealed that two ions associate per hGH dimer in a cooperative... 

Desiderio DM. 1999. Mass spectrometric analysis of neuro-peptidergic systems in the human pituitary and cerebrospinal fluid. J Chrmoatogr B Biomed Sci Appl 731 3. 

Zhan X, Desiderio DM. 2003. Heterogeneity analysis of the human pituitary proteome. Clin Chem 49 1740. 

Scheffer GL, Wijngaard PL, Flens MJ, Izquierdo MA, Slovak ML, Pinedo HM, Meijer CJ, Clevers HC, Scheper RJ (1995) The drug resistance-relateid protein LRP is Ae human major vault protein. Nat Med 1 578-582 Schiemann U, Assert R. Moskopp D, Gellner R, Hengst K, Gullotta F, Domschke W, Pfeiffer A (1997) Analysis of a protein kinase C-alpha mutation in human pituitary tumours. ] Endocrinol 153 131-137... 

Mastronardi, L., Guiducci, A., Spera, C., Puzzilli, F., Liberati., and Maira, G. 1999. Ki-67 labelling index and invasiveness among anterior pituitary adenomas Analysis of 103 cases using the MIB-1 monoclonal antibody./. Clin. Pathol. 52 107-111. 

Kusmierz, X X Sumrada, R. Desiderio, D. M. 1990. Fast atom bombardment mass spectrometric quantitative analysis of methionine-enkephalin in human pituitary tissues. Anal Chem., 62,2395-2400. 

Fischli, W., Goldstein, A., Hunkapiller, M. W., and Hood, L. E. (1982). Isolation and amino add sequence analysis of a 4,000-dalton dynorphin from porcine pituitary. Proc. Natl. Acad. Sci. USA 79, 5435-5437. 

Liu YF, Jakobs KH, Rasenick MM, Albert PR. G protein specificity in receptor-effector coupling. Analysis of the roles of G0 and Gi2 in GH4C1 pituitary cells. J Biol Chem 1994 269 13,880-13,886. 

Type II deiodinase activity is low in unsupplemented tissue homogenates but is stimulated by DTT [71-74,82,83] and to a lesser extent also by GSH [72]. The DTT concentrations required for maximal enzyme stimulation in the CNS and pituitary seem higher than in BAT and also than those necessary for the type I deiodinase in liver and kidney. Kinetic analysis of the deiodination of varying substrate (T4, rT3) concentrations at different cofactor (DTT) levels have indicated a sequential reaction mechanism for the type II deiodinase [73,82,83]. This is very suggestive of the formation of a ternary enzyme-substrate-cofactor complex in the catalytic process [82], The physiological cofactor of the type II deiodinase has not been identified but it has been observed that GSH depletion with diamide or diethylmaleate impairs T4 to T3 conversion in GH3 pituitary tumor cells [93]. 

Although the detailed features of the interactions involved in cortisol secretion are still unknown, some observations indicate that the irregular behavior of cortisol levels originates from the underlying dynamics of the hypothalamic-pituitary-adrenal process. Indeed, Ilias et al. [514], using time series analysis, have shown that the reconstructed phase space of cortisol concentrations of healthy individuals has an attractor of fractal dimension dj = 2.65 0.03. This value indicates that at least three state variables control cortisol secretion [515]. A nonlinear model of cortisol secretion with three state variables that takes into account the simultaneous changes of adrenocorticotropic hormone and corticotropin-releasing hormone has been proposed [516]. 

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