Adrenocorticotropic hormone, analysis

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]. 

Saffran M, Matthews EK, Pearlmutter F (1971) Analysis of the response to ACTH by rat adrenal in a flowing system. Rec Progr Hormone Res 27 607-630 Staehelin M, Barthe P, Desaulles P (1965) On the mechanism of the adrenal gland response to adrenocorticotropic hormone in hypophysectomized rats. Acta Endocr (Kbh) 50 55-64... 

The use of corticosteroids in the treatment of septic shock has been a topic of controversy for many years. A meta-analysis of early studies of steroids in sepsis demonstrated a lack of benefit and potential harm in sepsis and septic shock. There is a renewed interest in corticosteroid use because of the increased awareness of adrenocortical insufficiency in critically ill patients with septic shock. Relative adrenal insufficiency has been defined as a poor adrenal response [<250 nmol/L (9 mcg/dL) irrespective of the initial serum cortisol level] to a dose of synthetic adrenocorticotropic hormone (ACTH), indicating a low fnnctional reserve of the adrenal cortex. Although absolute insufficiency is rare, relative adrenocortical insufficiency in the presence of normal or high cortisol concentrations at baseline is present in 30% to 50% of patients with septic shock and is associated with a poor outcome. ... 

The Sequazyme C-peptide sequencing kit enables peptide digestion followed by analysis of sequentially truncated peptides using MALDI-TOF-MS. Before digesting and analyzing unknown samples of the peptide (adrenocorticotropic hormone), the activity of the enzyme carboxypeptidase Y (CPY) was checked by dilution experiments with ammonium citrate buffer (pH = 6.1), CPY dilution and the peptide standard angiotensin I. The adrenocorticotropin ACTH (18-39) fragment (0.3 pL) was transferred as a solution of 5 x 10 5M in a 1 1... 

ACTH adrenocorticotropic hormone ANOVA analysis of variance... 

Protein adrenocorticotropic hormone preparations from sheep have been shown to be of multiple nature when subjected to zone electrophoresis, both in filter paper (Li, 1952) and in starch (Porath, personal communication). Only one of the zones possessed biological activity. Partial peptic and hydrochloric acid hydrolyzates of the active zone also gave several zones. As the active component was strongly adsorbed in filter paper, analysis in a starch medium was preferred. The active zone from this possessed very high activities but was still not a single defined substance. 

Assays for melanocyte-stimulating hormone were carried out by Mr. S. Kulovich using the in vitro frog skin assay (1). Subcutaneous assay for adrenocorticotropic activity (2), based on ascorbic acid depletion in hypophysectomized rats, was performed by Dr, J.D. Fisher of the Armour Laboratories. Acid hydrolysates (constant boiling HCl, deaerated, 22 hours, 110°) of these fractions were characterized by automatic amino acid analysis with a Spinco model 120B analyzer. The number of tryptophan residues in the intact peptide was estimated from the ultraviolet absorption curves made with a Cary model 15 spectrophotometer. Electrophoresis was carried out on Whatman paper No. 1 with pyridine-acetate buffer, pH 6.5, and 4 molar urea for 3 hours at 26 volts per cm. Peptides were detected with bromphenol blue(3). 

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