Cortisol reactivity

Ouellet-Morin, I., Boivin, M., Dionne, G., Lupien, S. J., Arsenault, L., Barr, R. G., Perusse, D., Tremblay, R. E. (2008). Variations in heritability of cortisol reactivity to stress as a function of early familial adversity among 19-month-old twins. Arch. Gen. Psychiatry. 65 211—218. 

Crystalline packing is an important parameter for auto-oxidation in the sohd state, as molecular oxygen must be able to access susceptible moieties in the molecule. Lyn et al. [63] showed that only one (hexagonal form) of the five different polymorphic forms of prednisolone tert-butylacetate were susceptible to oxidation, yielding the 11-ketone product. The authors attributed this oxidative reactivity to channels in the crystal structure allowing access to the labile 11-alcohol position. Bryn et al. [64] also identified a similar phenomenon in the photo-mediated oxidation of 21-cortisol tert-butylacetate to the corresponding ketone. 

Fukata J (1989) Two-site immunoradiometric assay for adreno-corticotrophin a cautionary study about the reactivity to its precursor molecules. Endocrinol Jpn 36 155-61 Ganong WF (1974) ACTH and the regulation of adrenocorticol secretion. N Engl J Med 290 1006 Genazzani AR (1975) Immunoreactive ACTH and cortisol plasma levels during pregnancy. Detection and partial purification of corticotrophin-like placental hormone the human chorionic corticotrophin (HCC). din Endocrinol (Oxf) 4 1-14... 

In most studies, the selectivities of the MIPs have been estimated by measuring the amount of each ligand required to displace 50% of the binding of radiolabelled imprint species to the MIP (IC50). The first MIA study reported excellent selectivity of the theophylline method for theophylline (1,3-dimethylxanthine) in the presence of the structurally related compound caffeine (1,3,7-trimethylxanthine) [3]. Despite their close resemblance (they differ by only one methyl group), caffeine showed less than 1 % cross-reactivity. A similar level of specificity was recorded for cortisol and corticosterone MIPs, which were able to detect the absence and presence of single hydroxyl groups and double bonds in the steroid structure [13]. 

Specificity The spiecificity of the antiserum was determined and fixed by determining the cross reactivity of substances having a structure similar to that of cortisol. 

Specificity The cross-reactivity of digitoxin, digitoxigenin, dihydrodigoxin, progesterone, testosterone, ouabain, cholesterol, prednisolone, cortisol, corticosterone, 17-P-estradiol and spironolactone is < 10%. 

One of the side effects of adrenocorticotropic hormone (ACTH) and corticoid therapy in humans is the development or reactivation of gastroduodenal ulcers. Daily subcutaneous administration of cortisol or A -cortisol to rats for 4 days results in the regular development of gastric ulcers (38). This procedure has been adapted to testing antiulcer activity (39). There are certain differences between steroid ulcers and "natural" ulcers in localization, rate of development, and severity (40). 

EUstrom M, Bengtsson A, Tylman M, et al. Evaluation of tissue trauma after laparoscopic and abdominal hysterectomy measurements of neutrophil activation and release of interleukin-6, cortisol, and C-reactive protein. J Am CoU Surg 1996 182 423-30. 

Almost all commercial radioimmunoassay methods for serum cortisol show some cross-reactivity with prednisolone. Because prednisone is converted to prednisolone in vivo, these kits cannot be used to analyze specimens from patients on prednisone therapy. The degree of crossreactivity with 11-DOC, corticosterone, and prednisone varies from 1% to 5% these cross-reactions are antiserum dependent. When high plasma concentrations of 11-DOC are found (such as in lip-hydroxylase deficiency or after administration of metyrapone), prefiminary extraction with carbon tetrachloride to remove this steroid is usually indicated. 

Karmazyn M, Manku MS, Horrobin DF. Changes of vascular reactivity induced by low vasopressin concentrations interactions with cortisol and lithium and possible involvement of prostaglandins. Endocrinology 1978 102 1230-1236. 

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