Degradation hormone

Thyroid hormones and most steroid hormones are associated with carrier proteins in the serum. The carrier proteins are called, appropriately, thyroxine-binding globulin, transcortin (for cortisol), and sex-steroid-binding protein. These proteins have a high affinity (Kd 10—9— 10 8 m) for their respective hormones. They buffer the concentration of free hormone and retard hormone degradation and excretion. The carrier proteins are distinguishable from the intracellular receptors for these hormones. 

Jain and coworkers showed that polysialylation significantly changes the PK/PD profile of insulin, prolonging the hypoglycemic activity after subcutaneous (SC) administration to T/O mice. Slight differences were observed between derivatives obtained with 22 kDa and 39 kDa polysialic acid these were attributed to the slower hormone absorption obtained with the latter polymer, which favors hormone degradation at the injection site and hinders the interaction with the receptor more efficiently than the former polymer [11]. 

Y. Fuse, D. H. Polk, R. W. Lam, A. L. Reviczky, and D. A. Fisher. Distribution and ontogeny of thyrotropin-releasing hormone degrading enzymes in rats. Am. J. PtysioL 259 E787-E79I (1990). 

Internalization of protein hormones is a principal means of hormone degradation in lysosomes through a receptor-mediated pathway [70], There may also be membrane-associated degradative activities for insulin (insulinase) and other protein hormones, however for EGF, degradation occurs exclusively through an intracellular process [68,71]. 

Pease K, Shen H, Acres GS, Rupnow JH, Dixon JE (1980) Alterations in levels of thyrotrophin releasing hormone and rates of hormone degradation in hypothalamic tissue of the developing rat. J Endocrinol 85(1) 55—61 Queen G, Vivian S, LaBella F (1975) Monolayer cultures of dispersed cells from bovine anterior pituitary responses to synthetic hypophysiotropic peptides. Can J Physiol Pharmacol 53(6) 1094-8... 

Chemists studying the hormone degradation producls present in the urine of hydroxyiic groups. When, subsequently, they did want to methylate the other... 

Chemists studying the hormone degradation products present Inthe urine of pregnant women needed to methylate the phenolic hydroxyl group of the steroid oestrlol. By using dIazomethane, they avoided reaction at the two other... 

Structurally similar compounds can also compete with endogenous hormones for the binding sites of metabolic enzymes and make the enzyme unavailable for normal hormone degradation. This would lead to a decreased clearance rate and prolong the half-life of circulating endogenous hormones. 

Endocrine Events Susceptible to Manipulation. There are a series of events which are common to the production and action of any hormone. These events include hormone synthesis, secretion and transport hormone-target cell receptor interaction target cell response and hormone degradation. Several of these events are susceptible to manipulation by external influences that might be devised into control strategies. 

Auxin Formation. Oxidation or transamination leads to the formation of indolepyruvic acid. Decarboxylation of the keto acid is presumed to result in the formation of indoleacetaldehyde, which can be oxidized by an aldehyde oxidase to indoleacetic acid (V). This compound is excreted by humans, but appears to be the natural auxin, a plant growth hormone. Degradation of auxin by plants appears to involve a peroxidase acting as an oxidase. Horseradish peroxidase plus Mn++ carry out the same... 

Grisolia, S., and Wallace, R., 1976, Insulin degradation by lysosomal extracts from rat liver model for a role of lysosomes in hormone degradation, Biochem. Biophys. Res. Commun. 70 22. 

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