Lecture+36_Endocrine1

Lipophilic hormones cross the membrane and bind with

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview:   hydrophilic hormones; highly water soluble, low lipid solubility, can’t be absorbed if taken orally for supplementa&on •  lipophilic hormones; highly lipid solubility, poorly soluble in water, can be taken orally Hormone Ac&ons •  Hydrophilic hormones bind with surface membrane receptors. •  Why not intracellular targets? •  Trigger a chain of intracellular events by means of a second- messenger pathway. •  Lipophilic hormones cross the membrane and bind with receptors inside the cell. •  Influence gene ac&vity, altering synthesis of intracellular proteins •  May also interact with membrane receptors Extracellular (first) messenger (Activates) GDP GTP ECF Plasma membrane G- protein- (Activates) coupled receptor Second messenger G- protein- intermediary 2 1 Adenylyl cyclase (effector protein) ICF 3 Inactive protein kinase A Active protein kinase A 4 Inactive designated protein (changes shape and function) Active designated protein 5 Key Phosphate Cellular response Fig. 4-25, p. 125 ECF Blood vessel Plasma protein carrier Steroid hormone Plasma membrane Cytoplasm Cellular response 1 9 Portion t...
View Full Document

Ask a homework question - tutors are online