7.2 Hormone Mechanisms of Action and Regulation Flashcards
What is an amplifier enzyme? Where do we see them?
An enzyme that amplifies a signal. We see this with g-protein coupled receptors, where a single hormone binding can lead to multiple second messenger molecules.
What is the name of the reactions and events downstream from a surface receptor?
Second messenger pathway/signal transduction pathway
Under what circumstances can steroid hormones have more rapid responses than usual?
Binding to surface receptor (e.g. typically G-protein coupled receptor), enabling for faster, shorter response.
What are tropic hormones?
Hormones that cause the release of hormones from another tissue
How many ways can hormone release be stimulated? What are they?
Three ways:
- Hormonal
- Neural
- Humoral
What is receptor up-regulation and down-regulation?
When a cell form/lose receptors for a specific molecule in response to rising hormone levels
Give an example of receptor down-regulation?
Type 2 Diabetes
What is permissiveness?
A hormone must be present to permit the action of another
What is synergism?
When two hormones produce an effect that’s greater than the sum of their effects
What is antagonism?
When one hormone decreases the effectiveness of another
Which organs do the bulk of hormone clearance?
Liver and kidneys
What are primary and secondary endocrine disorders?
Primary: Problem with gland itself
Secondary: Hypo/Hypersecretion due to too little/much stimulation; often has to do with pituitary gland
What factors influence the level of active hormones in blood plasma?
- Rate of secretion (most important)
- Rate of binding to carrier proteins
- Rate of metabolism (activation/degradation)
