HLSC 1F90 Lecture Notes - Lecture 13: Pituitary Adenoma, Anterior Pituitary, Post-Translational Modification
7 Apr 2017
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Hormones & human body function (endocrinology) | dr. e. l. tsiani. Half-life indicates length of activity: typically as a measure of the time needed to decrease its concentration in the circulation, liver and kidneys. Peptide or protein hormones: glucagon, insulin, growth hormone. Amino acid-derived or amine hormones: thyroid hormones, catecholamines. Prohormone: smaller, inactive, proteolytic, post-translational modification. Peptide/protein hormones: bind surface membrane receptors, cellular response through signal transduction system. Cholesterol-derived: lipophilic and easily cross membranes, synthesized on demand in parent cell smooth er- diffuse out. Bind carrier proteins in blood: lengthens their half-life. Cytoplasmic or nuclear receptors: genomic effect to activate or repress genes for protein synthesis, slower acting. Derived from one of two amino acids: tyrosine, tryptophan. Homeostasis: maintenance of static, or constant conditions of the internal environment. Control mechanisms involved in the regulation of body functions to maintain homeostasis. Negative feedback control mechanisms oppose a change by creating a response that is opposite to the initial disturbance.
