April 25, 2014 – Chemical signals and hormones I No pre-lecture quiz
description
Transcript of April 25, 2014 – Chemical signals and hormones I No pre-lecture quiz
![Page 1: April 25, 2014 – Chemical signals and hormones I No pre-lecture quiz](https://reader031.fdocuments.in/reader031/viewer/2022013004/56816532550346895dd7b9dd/html5/thumbnails/1.jpg)
April 25, 2014 – Chemical signals and hormones I
1. No pre-lecture quiz2. Cell-to-cell signaling – an introduction3. Endocrine systems & hormones4. Case study: The importance of thyroid hormones (T3 & T4)
![Page 2: April 25, 2014 – Chemical signals and hormones I No pre-lecture quiz](https://reader031.fdocuments.in/reader031/viewer/2022013004/56816532550346895dd7b9dd/html5/thumbnails/2.jpg)
Introduction to chemical signals in animals – Major categoriesEndocrine cells may be organized into glands
![Page 3: April 25, 2014 – Chemical signals and hormones I No pre-lecture quiz](https://reader031.fdocuments.in/reader031/viewer/2022013004/56816532550346895dd7b9dd/html5/thumbnails/3.jpg)
Neurotransmitters
Introduction to chemical signals in animals – Major categories
![Page 4: April 25, 2014 – Chemical signals and hormones I No pre-lecture quiz](https://reader031.fdocuments.in/reader031/viewer/2022013004/56816532550346895dd7b9dd/html5/thumbnails/4.jpg)
![Page 5: April 25, 2014 – Chemical signals and hormones I No pre-lecture quiz](https://reader031.fdocuments.in/reader031/viewer/2022013004/56816532550346895dd7b9dd/html5/thumbnails/5.jpg)
![Page 6: April 25, 2014 – Chemical signals and hormones I No pre-lecture quiz](https://reader031.fdocuments.in/reader031/viewer/2022013004/56816532550346895dd7b9dd/html5/thumbnails/6.jpg)
Neuroendocrine pathway
Neuroendocrinesignal
Endocrine pathway Neuroendocrine-to-endocrine pathway
Neuroendocrinesignal
Endocrinesignal
Endocrinesignal
Endocrine cell
Effectorcell
Response
Response
Stimulus Stimulus
Feed
back
inhi
bitio
n
Feed
back
inhi
bitio
n Sensor cell
Effectorcell
Feed
back
inhi
bitio
n
Neural signal
CNS
Stimulus
Sensor cell
Neural signal
CNS
Response
Effectorcell
Endocrine cell
Endocrine systems are regulated by negative feedback
![Page 7: April 25, 2014 – Chemical signals and hormones I No pre-lecture quiz](https://reader031.fdocuments.in/reader031/viewer/2022013004/56816532550346895dd7b9dd/html5/thumbnails/7.jpg)
Steroids
CortisolEpinephrine
Amino AcidDerivatives
Receptor
Secretin
Peptides and Polypeptides
Receptor
Receptor
Target cell
Most not lipid soluble;bind to receptors onsurface of target cell
Not lipid soluble;bind to receptors onsurface of target cell
Lipid soluble;bind to receptorsinside target cell
Chemical characteristics of hormones – major classes
![Page 8: April 25, 2014 – Chemical signals and hormones I No pre-lecture quiz](https://reader031.fdocuments.in/reader031/viewer/2022013004/56816532550346895dd7b9dd/html5/thumbnails/8.jpg)
Hormone Transport and Action on Target
![Page 9: April 25, 2014 – Chemical signals and hormones I No pre-lecture quiz](https://reader031.fdocuments.in/reader031/viewer/2022013004/56816532550346895dd7b9dd/html5/thumbnails/9.jpg)
Hydrophobic messengers pass into cell where they bind with transcription factors which affect gene expression.
![Page 10: April 25, 2014 – Chemical signals and hormones I No pre-lecture quiz](https://reader031.fdocuments.in/reader031/viewer/2022013004/56816532550346895dd7b9dd/html5/thumbnails/10.jpg)
Hydrophilic hormones bind to a receptor on the cell membrane which causes several reactions known as a signal transductionpathway. This can affect the properties of enzymes/proteins, etc. or it may affect gene expression.
![Page 11: April 25, 2014 – Chemical signals and hormones I No pre-lecture quiz](https://reader031.fdocuments.in/reader031/viewer/2022013004/56816532550346895dd7b9dd/html5/thumbnails/11.jpg)
This picture shows a hormone traveling throughthe cell membrane and binding with a transcription factor.
Which of the following statements are true?
A) This is a membrane soluble (hydrophobic) hormone thatalters gene transcription.
B) This is a membrane soluble (hydrophobic) hormone thatalters immediate enzyme activity and cell processes.
C) This is a membrane insoluble (hydrophilic) hormone thatalters gene transcription.
D) This is a membrane insoluble (hydrophilic) hormone thatalters immediate enzyme activity and cell processes.
![Page 12: April 25, 2014 – Chemical signals and hormones I No pre-lecture quiz](https://reader031.fdocuments.in/reader031/viewer/2022013004/56816532550346895dd7b9dd/html5/thumbnails/12.jpg)
Barry Bonds was accused of using a steriod ‘the cream’ to increase his athletic performance. He supposedly applied this to his skin. What does this tell you about the nature of this hormone?
A. The hormone was membrane insoluble.B. The hormone was membrane soluble.C. The hormone initiated a signal transduction pathway.D. A and C
![Page 13: April 25, 2014 – Chemical signals and hormones I No pre-lecture quiz](https://reader031.fdocuments.in/reader031/viewer/2022013004/56816532550346895dd7b9dd/html5/thumbnails/13.jpg)
Steroids
PolypeptidesAmino acid derivatives
Major endocrine glands
![Page 14: April 25, 2014 – Chemical signals and hormones I No pre-lecture quiz](https://reader031.fdocuments.in/reader031/viewer/2022013004/56816532550346895dd7b9dd/html5/thumbnails/14.jpg)
Figure 47-3-1Hypothalamus
Growth-hormone-releasing hormone:stimulates release of GH from pituitarygland
Corticotropin-releasing hormone (CRH):stimulates release of ACTH from pituitarygland
Gonadotropin-releasing hormone:stimulates release of FSH and LH from pituitary gland
Thyroid-releasing hormone: stimulatesrelease of TSH from thyroid gland
Antidiuretic hormone (ADH): promotesreabsorption of H2O by kidneys
Oxytocin: induces labor and milk releasefrom mammary glands in females
Steroids
PolypeptidesAmino acid derivatives
![Page 15: April 25, 2014 – Chemical signals and hormones I No pre-lecture quiz](https://reader031.fdocuments.in/reader031/viewer/2022013004/56816532550346895dd7b9dd/html5/thumbnails/15.jpg)
Figure 47-3-3
Pituitary gland
Thyroid-stimulating hormone (TSH):stimulates thyroid gland to secretethyroxine
Prolactin: stimulates mammary glandgrowth and milk production in females
Follicle-stimulating hormone (FSH)and luteinizing hormone (LH): involvedin production of sex hormones;regulate menstrual cycle in females
Growth hormone (GH): stimulates growth
Adrenocorticotropic hormone (ACTH):stimulates adrenal glands to secreteglucocorticoids
Steroids
PolypeptidesAmino acid derivatives
![Page 16: April 25, 2014 – Chemical signals and hormones I No pre-lecture quiz](https://reader031.fdocuments.in/reader031/viewer/2022013004/56816532550346895dd7b9dd/html5/thumbnails/16.jpg)
Figure 47-3-2
Adrenal glands
Thyroid gland
Thyroxine: increases metabolic rateand heart rate; promotes growth
Kidneys
Epinephrine: produces many effectsrelated to short-term stress response
Aldosterone: increases reabsorption ofNa+ by kidneys
Cortisol: produces many effects related toshort-term and long-term stress responses
Vitamin D: decreases blood Ca2+
Testes (in males)
Erythropoietin (EPO): increasessynthesis of red blood cells
Testosterone: regulates developmentand maintenance of secondary sexcharacteristics in males; other effects
Steroids
PolypeptidesAmino acid derivatives
![Page 17: April 25, 2014 – Chemical signals and hormones I No pre-lecture quiz](https://reader031.fdocuments.in/reader031/viewer/2022013004/56816532550346895dd7b9dd/html5/thumbnails/17.jpg)
Figure 47-3-4
Parathyroid glands
Pancreas (islets of Langerhans)
Ovaries (in females)
Insulin: decreases blood glucose
Glucagon: increases blood glucose
Estradiol: regulates development andmaintenance of secondary sexcharacteristics in females; other effectsProgesterone: prepares uterus for pregnancy
Parathyroid hormone (PTH): increases blood Ca2+
Steroids
PolypeptidesAmino acid derivatives
![Page 18: April 25, 2014 – Chemical signals and hormones I No pre-lecture quiz](https://reader031.fdocuments.in/reader031/viewer/2022013004/56816532550346895dd7b9dd/html5/thumbnails/18.jpg)
Thyroid Hormone
Thyroid hormone:- Actually two hormones (T3/T4)
Mammals mainly secrete T4 - but some T4 is converted under certain circumstances- Same receptor binds both, but ↑affinity for T3
T3/T4 are membrane soluble- ↑metabolism in muscles, heart, liver & kidney
T4 T3
![Page 19: April 25, 2014 – Chemical signals and hormones I No pre-lecture quiz](https://reader031.fdocuments.in/reader031/viewer/2022013004/56816532550346895dd7b9dd/html5/thumbnails/19.jpg)
![Page 20: April 25, 2014 – Chemical signals and hormones I No pre-lecture quiz](https://reader031.fdocuments.in/reader031/viewer/2022013004/56816532550346895dd7b9dd/html5/thumbnails/20.jpg)
![Page 21: April 25, 2014 – Chemical signals and hormones I No pre-lecture quiz](https://reader031.fdocuments.in/reader031/viewer/2022013004/56816532550346895dd7b9dd/html5/thumbnails/21.jpg)
Thyroid Gland
![Page 22: April 25, 2014 – Chemical signals and hormones I No pre-lecture quiz](https://reader031.fdocuments.in/reader031/viewer/2022013004/56816532550346895dd7b9dd/html5/thumbnails/22.jpg)
Low levels of iodine cause ~90% of goiters.Why?
![Page 23: April 25, 2014 – Chemical signals and hormones I No pre-lecture quiz](https://reader031.fdocuments.in/reader031/viewer/2022013004/56816532550346895dd7b9dd/html5/thumbnails/23.jpg)
Figure 47-8
T3
Juvenile frog (tadpole)
T3
LocomotionRespiration
Excretion
Nutrition
Swim via movements of muscular tailGas exchange occurs in gills, across skin,and in lungsMost are herbivorous; have a long gutspecialized for digesting algae and plantsMost nitrogenous wastes excreted asammonia
Adult frog
LocomotionRespiration
Nutrition
Excretion
Gas exchange occurs across skin, and inlungs
Tailless; walk or hop
Most nitrogenous wastes excreted as urea
Most are carnivorous; have a large mouthor long tongue for catching prey; short gutspecialized for digesting proteins
![Page 24: April 25, 2014 – Chemical signals and hormones I No pre-lecture quiz](https://reader031.fdocuments.in/reader031/viewer/2022013004/56816532550346895dd7b9dd/html5/thumbnails/24.jpg)
Researchers figured out that tadpoles could be induced to undergo metamorphosis by feeding them ground up thyroid glands from horses.
They could also prevent metamorphosis by surgically removing the tadpoles' thyroid glands.
In juvenile amphibians, cells respond to increased levels of T3 in one of three ways:
(1) They may begin growing and form new structures, such as legs;(2) They may die, as in cells that form the tadpole's tail; or(3) They may change structure and function.
![Page 25: April 25, 2014 – Chemical signals and hormones I No pre-lecture quiz](https://reader031.fdocuments.in/reader031/viewer/2022013004/56816532550346895dd7b9dd/html5/thumbnails/25.jpg)
Researchers figured out that tadpoles could be induced to undergo metamorphosis by feeding them ground up thyroid glands from horses.
They could also prevent metamorphosis by surgically removing the tadpoles' thyroid glands.
In juvenile amphibians, cells respond to increased levels of T3 in one of three ways:
(1) They may begin growing and form new structures, such as legs;(2) They may die, as in cells that form the tadpole's tail; or(3) They may change structure and function.
Take home message: The same hormone can multiple physiological effects
![Page 26: April 25, 2014 – Chemical signals and hormones I No pre-lecture quiz](https://reader031.fdocuments.in/reader031/viewer/2022013004/56816532550346895dd7b9dd/html5/thumbnails/26.jpg)
Anadromous versus Resident Stream Sticklebacks
Higher metabolic rates
Migrate from ocean to freshwater to breed
Bigger
Lower metabolic rates
Permanent residents in freshwater
Smaller
![Page 27: April 25, 2014 – Chemical signals and hormones I No pre-lecture quiz](https://reader031.fdocuments.in/reader031/viewer/2022013004/56816532550346895dd7b9dd/html5/thumbnails/27.jpg)
Anadromous versus Resident Stream Sticklebacks
Higher metabolic rates
Migrate from ocean to freshwater to breed
Bigger
Lower metabolic rates
Permanent residents in freshwater
Smaller
I-Clicker - Which one has higher levels of thyroid hormone?
A) MarineB) Stream
![Page 28: April 25, 2014 – Chemical signals and hormones I No pre-lecture quiz](https://reader031.fdocuments.in/reader031/viewer/2022013004/56816532550346895dd7b9dd/html5/thumbnails/28.jpg)
Kitano, J. et al. 2010. Adaptive divergence in the thyroid signaling pathway in the stickleback radiation. Current Biology 20:2124-2130.
Marine Stream
![Page 29: April 25, 2014 – Chemical signals and hormones I No pre-lecture quiz](https://reader031.fdocuments.in/reader031/viewer/2022013004/56816532550346895dd7b9dd/html5/thumbnails/29.jpg)
Does T4 really affect metabolism?
Experiment:
For both marine and stream fish . . .
1. Expose some to higher levels of thyroid (T4)
2. Some unmanipulated (control)
3. Expose some to a thyroid inhibitor
Measure Oxygen Consumption.
![Page 30: April 25, 2014 – Chemical signals and hormones I No pre-lecture quiz](https://reader031.fdocuments.in/reader031/viewer/2022013004/56816532550346895dd7b9dd/html5/thumbnails/30.jpg)
Experiment:
For both marine and stream fish . . .
1. Expose some to higher levels of thyroid (T4)
2. Some unmanipulated (control)
3. Expose some to a thyroid inhibitor
Measure Oxygen Consumption inboth marine and freshwater fish.
What are the predictions?
Does T4 really affect metabolism?
![Page 31: April 25, 2014 – Chemical signals and hormones I No pre-lecture quiz](https://reader031.fdocuments.in/reader031/viewer/2022013004/56816532550346895dd7b9dd/html5/thumbnails/31.jpg)
Experiment:
Expose some to higher levels of thyroid (T4)
Some unmanipulated (control)
Expose some to a thyroid inhibitor
Does T4 really affect metabolism?
![Page 32: April 25, 2014 – Chemical signals and hormones I No pre-lecture quiz](https://reader031.fdocuments.in/reader031/viewer/2022013004/56816532550346895dd7b9dd/html5/thumbnails/32.jpg)
Elevated T4 levels in marine fish were associated with upregulation of genes involved in aerobic metabolism (OXPHOS)
Does T4 really affect metabolism?
![Page 33: April 25, 2014 – Chemical signals and hormones I No pre-lecture quiz](https://reader031.fdocuments.in/reader031/viewer/2022013004/56816532550346895dd7b9dd/html5/thumbnails/33.jpg)
There are lots of other elements of the fish that differ, possibly due to thyroid hormone.
-initiation of migration (for marine fish)-activity levels
![Page 34: April 25, 2014 – Chemical signals and hormones I No pre-lecture quiz](https://reader031.fdocuments.in/reader031/viewer/2022013004/56816532550346895dd7b9dd/html5/thumbnails/34.jpg)
There are lots of other elements of the fish that differ, possibly due to thyroid hormone.
-initiation of migration-activity levels
-DNA polymorphisms in binding sites of TSH
![Page 35: April 25, 2014 – Chemical signals and hormones I No pre-lecture quiz](https://reader031.fdocuments.in/reader031/viewer/2022013004/56816532550346895dd7b9dd/html5/thumbnails/35.jpg)
Altering individual behaviors by altering overall thyroid levels seems like a pretty blunt way to go about changing specific phenotypes.
How could this system be fine-tuned to optimize specific traits under different contexts?
A.) changes in TRH expressionB.) changes in TSH expressionC.) alterations of TSH receptorsD.) alteration of T3/T4 receptors in specific cell types.