HLTB22H3 Lecture Notes - Lecture 2: Myeloma Protein, Adrenal Insufficiency, Kidney Stone Disease
Document Summary
Endocrinology: the scientific study of hormones and the endocrine system. The chemical structure of a hormone determines how it acts. Functional classes of chemical messengers. Lipophobic: does not interact with fat. Lipophilic: interacts well with fat. Steroids: synthesized from cholesterol; only gonadal and adrenocortical hormones are steroids; lipid soluble and can cross the plasma membrane. Eicosanoids: include leukotrienes (signaling chemicals that mediate inflammation and some allergic reactions) and prostaglandins (multiple targets and effects, ranging from. Hormones act through second messengers or by activating specific genes. Target cells: cells that have specific receptors that bind to specific hormones. Once bound to the receptor, the hormones alter cell activity, by increasing or decreasing normal cellular processes. Insulin and certain growth factors work without second messengers. Phosphodiesterase: intracellular enzyme that degrades camp, causing action of camp to only persist briefly. The pip2- calcium signaling mechanism: intracellular calcium ions act as second messenger. Ip3: inositol triphosphate; releases ca2+ from intracellular storage sites.
