Assessment of Endocrine Function Flashcards Preview

S&F IV: Exam One > Assessment of Endocrine Function > Flashcards

Flashcards in Assessment of Endocrine Function Deck (15):
1

Two-site immunometric assay

Enzyme is added to coated antibody well; more antibody is added to bind to other part of enzyme

=>Formation of compound is measure spectrophotometrically

2

Bioassay

Determines the circulating pool of biologically active hormone by using hormone receptors to measure enzyme concentration in place of antibodies

*Could also measure the formation of secondary messengers

3

Stimulation Tests

Test substance is administered; amount of hormone produced by gland is measure

-Substances could be exogenous hormones, physiological stimuli

*Used when a gland is thought to be HYPOfunctional

4

Suppression Tests

Assesses the functioning of the negative feedback loop; failure to suppress is indicative of HYPERfunctioning gland

5

Kd

Dissociation constant= 1/Ka

*Is an indicator of receptor affinity (inversely related)

*Also equivalent to the concentration of hormone required for 1/2[HR]

6

Conditions that affect [H]

Endogenous signals

Dysunctional glands

7

Conditions that affect Ka

Covalent/Allosteric Receptor Modifications

Altered pH

Antibodies to receptor

Mutations

8

Conditions that affect [R]

Altered rate of receptor synthesis/degradation

Compartmentalization of the receptors

9

Threshold

Minimum concentration of a hormone required to produce a detectable response

10

ED50

Sensitivity- half the concentration of hormone required to produce the maximum response

11

Maximum Response

the effect produced by saturating the hormone

12

ED50>Kd

Spare receptors present

Greatly enhances the sensitivity to the hormone

*May play a role in hormone degradation via receptor-mediated endocytosis

13

Maximum responsiveness decreases

Caused by: decreased # of responsive cells
increased conc. of non-competitive inhibitors
decreased # of receptors

*Cannot be overcome by increased [H]; unlike receptor sensitivity

14

Metabolic Clearance Rate

Rate of disappearance from plasma/Concentration of the hormone in the plasma

*Inversely related to half-life

15

Hormone Response

HR= Ka(H)(R)