Hormones/Cytokines W6

Question 1

What way do hormones/cytokines regulate anabolic processes?

Answer 1

Upstream

Question 2

What hormones promote anabolism?

Answer 2

Hepato growth factor
IL-5/ IL-6
Fibroblast Growth factor
Leukaemia Inhibitory factory
Insulin

Question 3

What happens to insulin levels during exercise?

Answer 3

They are suppressed

Question 4

What does insulin induce?

Answer 4

Mitosis
Differentiation of satellite cells

Question 5

What does insulin greater affect?

Answer 5

Attenuating proteolysis rather than protein synthesis

Question 6

What does IGF-1 do?

Answer 6

Main anabolic response for the body
Enhances effects in mechanical loading

Question 7

Where are IGF-1 receptors found?

Answer 7

Satellite cells
Adults myofibres
Schwann cells

Question 8

What are the 3 isoforms of IGF-1?

Answer 8

Systemic form: IGF-1Ea
Systemic form: IGF-1Eb
Splice variant: IGF-1Ec

Question 9

What does IGF-1Ea do?

Answer 9

Enhance fusion of satellite cells with muscle fibres
Facilitates donation of myonuclei
Maintains optimal DNA: protein in muscle

Question 10

What does IGF-1Eb and IGF-1Ec do?

Answer 10

Activates satellite cells
Mediates proliferation and differentiation

Question 11

How does IGF-1 induce hypertrophy?

Answer 11

Autocrine and Paracrine manner

Question 12

How does IGF-1 promote anabolism?

Answer 12

Increasing rate of protein synthesis in differentiated myofibres

Question 13

What does IGF-1 activate?

Answer 13

L-type Ca channel gene expression

Question 14

What happens when the L-type Ca channel gene expression is activated?

Answer 14

Increased intracellular Ca2+ concentrations

Activation of multiple anabolic Ca2+ dependent pathways

Question 15

What is testosterone?

Answer 15

Cholesterol derived
Anabolic effect on tissue

Question 16

How does testosterone interact with receptors on neurons?

Answer 16

Increase cell body size/ amount of neurotransmitters released
Regenerate nerves

Question 17

How is testosterone synthesised and secreted?

Answer 17

Leydig cells (testes)

Question 18

How can weakly bound testosterone become active?

Answer 18

By rapidly disassociating from albumin

Question 19

What happens when unbound testosterone binds to androgen receptors?

Answer 19

Causes conformational change
Transport testosterone to the cell nucleus to interact with DNA

Question 20

How does testosterone promote anabolsim?

Answer 20

Increasing protein synthetic rate
Inhibiting protein breakdown

Question 21

How does does testosterone contribute to protein accretion?

Answer 21

Indirectly
Stimulates the release of anabolic hormones

Question 22

What does GH do?

Answer 22

Induces fat metabolism toward mobilisation of triglycerides

Stimulating cellular uptake/ incorporation of amino acids into various proteins

Question 23

What does GH do when there is absence of mechanical loading?

Answer 23

Upregulates mRNA of systemic IGF-1

Mediates nonhaptic IGF-1 gene expression in an autocrine/paracrine manner

Question 24

What is the GH secreted by?

Answer 24

Anterior pituitary gland

Question 25

In muscle fibres, how does GH effect it?

Answer 25

Increases hypertrophy in type I and type II

Question 26

What does a hypertrophic facilitate?

Answer 26

Fibre recovery

Question 27

What is GH releasement associated with?

Answer 27

Marked upregulation of iGF-1gene in muscle so that more is spliced toward the MGF isoform

Question 28

What does GH regulate?

Answer 28

Immune function
Bone modelling
Extracellular fluid volume

Question 29

How do hypertrophic responses occur?

Answer 29

Enhanced interaction with muscle cell receptors