Hormones

Assignment

Audesirk, Audesirk & Byers Chapter 37

Today's musical selection
Weird Al Yankovic Pancreas

Figure (Chapter 37 opener)
case study "losing on artificial hormones"
Of course testosterone and other anabolic steroids favor muscle growth.
Also stimulants, growth hormone, diuretics, masking compounds, erythropoietin (EPO), more.
Box and paper detail the work of Prof. Don Catlin
Paper is dated 2004, so there have been many further cases.
Tour de France, Olympics, etc. - baseball is a special case because of a century of worship of records and record holders.
Hard for those who do the testing to stay ahead of new and innovative cheaters
New steroids like THG (tetrahydrogestrinone)
Testosterone itself is hard to judge, because it is naturally occuring, but synthetic has lower 13C/12C.
Also there's blood doping
There are so many health (and legal and career) dangers of messing around!
Balco (Bay Area Laboratory Cooperative) provides know-how and drugs and is networked with athletes.

Introduction

Table 37-1
Metazoans (animals with more cells than protozoans) require systems of integration
INTEGRATION: Hormones, paracrine (local) & nervous system
"endocrine" - ductless, into blood stream
vs. exocrine (like digestive - saliva etc.)

Figure 37-2
Three steps:
cells with blood vessels for release
hormone transported in the circulation
target cell with receptor

Two mechanisms

Figure 37-3
(1) receptor molecule on membrane

Figure 37-4
(2) enter cell and bind receptor

Overview

Figure 37-1
I. Traditionally, this material starts with a picture of the major glands

Figure 37-6
II. Then it covers Pituitary three ways
(1) posterior pituitary
(2) anterior pituitary as "master gland" (and the other glands it controls)
(3) anterior pituitary (affects not mediated through other glands)

III. Then it covers other glands (not controlled by the pituitary)


Posterior pituitary

Figure 37-8
(related to kidney coverage)
neurosecretion from hypothalamus (peptides)
oxytocin (milk, delivery)
(synthetic to induce labor)

Figure
Chapter 38 case study ("How do I love thee?")
hormones involved in love, oxytocin called the trust hormone

Covered in Excretion lecture: ADH action on kidney
vasopressin (ADH), H2O and blood pressure
alcohol, caffein inhibit anti [diuresis] hormone

Anterior pituitary

Figure 37-10
Secretion of releasing (and inhibiting) hormones (peptides) at pituitary stalk
Portal system
Anterior pituitary and its hormones (peptides)
Thyroid hormones
Influence on metabolism, but not as obviously as epinephrine, insulin, glucagon or even glucocorticoids.
Negative feedback with pituitary
Hypothalamus -TRF-> + Ant. Pituit. -TSH->+ Thyroid -> thyroxine-
- neck thyroxin (T4), triiodothyroxine (T3) iodine, sea food (and iodized salt)
T3 and T4 (Fig. 11.3 shown in an earlier lecture)

Figure 37-9
Goiter (thyroid overgrows if too little iodine in diet)
Cretinism if too little in infant, hypothyroid, hyperthyroid
Change in salmon during salt to fresh water change, metamorphosis in frog
Problem of radioactive iodine (like from reactor leaks) - helps to take large doses of non-radioactive iodine to compete

Table 37-3
So many more examples!

Non-trophic hormones
(not where pituitary acts as master gland to control other glands)

GH - 200 a.a. -bone, muscle, not fat,

Figure 37-7
GH - gigantism (bones grow long if too much GH when young), dwarfism (if too little GH when young), acromegaly (bones grow too thick if too much GH when already grown up, danger of GH abuse), abuse by body builders, dangers of extracts,, now available through recombinant DNA research

gonadotropins
"Master Gland"
sex hormones from pituitary (more details later):
LH (female) = ICSH (male); (luteinizing) (interstitial cell)
FSH (follicle)

Adrenal cortex

Figure 37-13
Adrenal cortex - Glucocorticoids stimulate metabolism, inhibits inflamation.
Mineralocorticoids, the best known being Aldosterone helps kidney retain salt
Adrenalectomy causes salt loss and salt appetite.
Sweat glands are not as efficient at retaining salt as kidney.
That is why "Gatorade" (electrolyte) is used by athletes.
Salt is also lost in cystic fibrosis (mutation of CFTR (cystic fibrosis transmembrane conductance regulator)


Adrenal medulla


Table 37.2
while on the topic of the adrenal gland,
Adrenal medulla - Epinephrine, (alias adrenalin) - activates body
Autonomic (vs voluntary) motor control: sympathetic (vs parasympathetic)
Sympathetic nervous system uses norepinephrine at postganglionic synapses.
Sympathetic - "fight or flight"
Helps in metabolism to release glucose to blood stream
Muscles activity up, peripheral circulation and digestion inhibited
Heart rate goes up

Glucose (insulin and Glucagon) and diabetes

Figure 37-12
In pancreas, which is largely a digestive exocrine gland, there are also islets of Langerhans (as shown in this picture from our histology course) which are the endocrine glands where the beta cells make insulin and the alpha cells make glucagon
Pancreas Insulin- sugar uptake into cells (blood sugar down), make glycogen in muscle & liver

Diabetes mellitus

Type 1 autoimmune disease beta cells are destroyed, young people, insulin dependent
inject insulin. protein, must inject
(vs steroid like "the pill" which can be taken orally)
Type 2, older people, genetic, correlated with overweight, non-insulin dependent
sugar in urine-
Eye problems (too many new blood vessels - angiogenesis) and cardiovascular problems
Brain is not insulin-dependent - coma from too much insulin because no glucose for brain
Glucagon mobilize sugar to blood like adrenalin
sugar regulates insulin and glucagon

Calcium homeostasis

Figure 37-11
Parathyroid - parathormone - blood Ca2+ up (from bones)
near thyroid gland in neck

Also
Thyroid - thyrocalcitonin - blood Ca2+ down
Vitamin D sunlight, rickets, fish oil, hormone, absorption from gut
Osteoporosis - bone deterioration with age especially in women
Ca2+ very important, muscle (later), nerve (later)

Estrogen

Menopause (pause in the menes) ["change of life" at about 50] - lack of estrogen.
(Some hysterectomy or ovarian cancer surgeries might also deplete because of ovarectomy).
Many symptoms, hot flashes most obvious short term effect.
Osteoporosis most obvious long term effect.
For me, this site worked with explorer, not netscape - estrogen (hormone) replacement therapy
Hotly contested (a lot of negative press lately), partly because estrogen increases chances of breast cancer.
There is a drug, Tamoxifen that blocks estrogen's effects, differently in different tissues.

Signal transduction

Figure 37-4
steroid hormone
gene transcription
signal transduction for G protein coupled receptor

Prostaglandins, etc

Table 37-2
prostaglandins (mediators of inflammation) are derived from fatty acid (arachidonic acid, 20:4) using cyclooxygenase (COX)
NSAIDS (non-steroidal anti-inflammtory drugs) aspirin, ibuprofen, inhibit prostaglandin synthesis by inhibiting cyclooxygenase (COX-1 & 2) nonspecifically, problems in stomach
Celebrex, Vioxx, Bextra inhibit prostaglandin synthesis by inhibiting cyclooxygenase (COX-2); popular for arthritus, but Merck pulled Vioxx 10/04 for increasing cardiovascular problems, and later Bextra was pulled.
Aspirin is anti-inflammatory, analgesic, antipyretic, anticoagulant, implicated in Reye's syndrome.

Questions used in 2007 relating to this outline

How might the authorities know whether a competitor had taken anabolic steroids.
(a) Look at the ratio of paracrine to endocrine secretions.
*(b) Look at the ratio of 13C/12C in testosteone.
(c) Check for acromegaly.
(d) Look at the ratio of CD4- vs CD8-expressing cells.
(e) Directly test for diuretics.

The pituitary is called the "master gland of the body" because
(a) most of the steroids are produced there.
(b) most of the exocrine secretions come from there.
(c) that is where insulin comes from.
*(d) it makes peptides that control other glands
(e) all the hormones that control calcium are located there.

Which of the following would prevent rickets?
*(a) sunshine
(b) adrenalin
(c) Prozac
(d) fibrinogen
(e) dopamine

"Endocrine secretions bind to G protein-coupled receptors on the cell's membrane."
(a) So do the antigens presented by macrophages.
(b) So do exocrine secretions.
(c) From there, they move in to bind to mRNA
*(d) By contrast, steroid hormones bind to receptors inside the cell.
(e) This is true for endocrine secretions but never for neurotransmitter substances.

A portal vessel connects the hypothalamus to the
(a) islets of Langerhans.
(b) interstitial cells between seminiferous tubules.
(c) mammary gland.
(d) collecting ducts shared among nephrons.
*(e) anterior pituitary.

Why would active people (e.g. athletes) prefer electrolyte drinks (e.g. Gatorade)?
*(a) because of salt loss by sweat glands
(b) to prevent insulin shock
(c) because activity inhibits oxytocin release from the adrenal medulla
(d) to make up for iodine deficiency
(e) because electrolytes are used for blood doping

Steroid hormones come from the gonads and the
(a) hypothalamus
*(b) adrenal cortex
(c) pancreas
(d) fat cells of adipose tissue
(e) thyroid

Why can't people with type I diabetes just eat their insulin?
(a) It would upset the homeostasis regulating thyroxne.
(b) That would cause osteoporosis.
(c) That would cause acromegaly.
(d) That would inhibit the formation of prostaglandins.
*(e) It's a protein and would be hydrolyzed.

Which of the following is delivered from the hypothalamus to the pituitary?
(a) inhibin
(b) vitamin D
(c) bicarbonate
*(d) GnRH (gonadotropin releasing hormone)
(e) progesterone

A "hormonal" disorder of too little vitamin D in toddlers is
(a) dwarfism.
(b) cretinism.
*(c) rickets.
(d) goiter.
(e) scurvey.

If a woman's contractions were too weak during labor, the obstetrician might add a synthetic version of (what?) to the intravenous drip?
(a) IgG
*(b) oxytocin
(c) thyroid hormone
(d) troponin
(e) glucagon

Questions used in 2002 relating to this outline (and other outlines)

Which is likely to be an autoimmune disease?
(a) acromegaly
(b) bronchitis
(c) myocardial infarction
*(d) diabetes
(e) cystic fibrosis

Classic experiments in which the adrenal gland was removed in rats
(a) demonstrated that the adrenal gland produces an antipyretic substance and is thus the center for temperature regulation.
(b) eliminated problems associated with ingesting radioactive iodine.
(c) caused a decrease in helper T cells.
(d) resulted in increased muscle mass because of anabolic steroids.
*(e) showed that there is an increased salt appetite.

Which would cause the bones to release calcium?
(a) cortisol
(b) glucagon
(c) vitamin D
(d) calcitonin
*(e) parathyroid hormone

Which is delivered via the portal vessel from the hypothalamus to the pituitary?
(a) angiotensin
(b) thrombin
(c) bicarbonate
*(d) peptide releasing factors
(e) steroid hormones

A disorder of too little thyroid hormone as an infant is
(a) dwarfism.
*(b) cretinism.
(c) rickets.
(d) laryngitis.
(e) emphysema.

Angiogenesis in the retina would most likely occur from
*(a) diabetes.
(b) vitamin D deficiency.
(c) Addison's disease.
(d) cretinism.
(e) cancer.

The prescription drugs for osteoarthritis, Vioxx and Celebrex, work
(a) as narcotic analgesics.
*(b) by targeting conversion of arachidonic acid to prostaglandins by COX-2.
(c) by inhibiting pituitary release of endorphins.
(d) to regulate calcium homeostasis.
(e) to stimulate inflammation.

To induce stronger uterine contractions, a synthetic version of what hormone is given?
(a) androgen
(b) estrogen
(c) progesterone
*(d) oxytocin
(e) FSH

ADH (antidiuretic hormone) affects
(a) the Malpighian tubules.
*(b) water recovery in the collecting duct.
(c) conversion of carbonic acid to bicarbonate in the blood stream.
(d) emergence of the adult insect from the pupa case.
(e) the transition from marine to fresh water physiology in salmon.

Rickets can be prevented by supplements of
(a) steroids.
(b) insulin.
(c) growth hormone.
(d) T3 and T4.
*(e) vitamin D.

Beer and coffee cause excessive urination
(a) by stimulating glomerular filtration.
(b) just because of the water they contain.
(c) by activating angiotensin.
(d) by activating interstitial cell stimulating hormone.
*(e) by inhibiting a hormone from the posterior pituitary.

Insulin shock
*(a) would happen when blood sugar gets too low.
(b) is from insufficient insulin.
(c) could only occur in untreated diabetics.
(d) is just another word for diabetes.
(e) commonly occurs when there are too many alpha cells in the islets of Langerhans.

A disorder of too little iodine intake as an adult is
(a) cirrhosis.
(b) polio.
(c) cystic fibrosis.
*(d) goiter.
(e) schizophrenia.

A disorder of too much growth hormone as an adult is
*(a) acromegaly.
(b) multiple sclerosis.
(c) treated by non-steroidal anti-inflammatory drugs (NSAIDS).
(d) gigantism
(e) cretinism

Which endocrine gland is involved in calcium regulation?
*(a) parathyroid
(b) pancreas
(c) juxtaglomerular apparatus
(d) interstitial cells
(e) pituitary

Which would be most likely to slow the development of osteoporosis?
(a) vitamin A
(b) iodine
*(c) vitamin D
(d) magnesium
(e) organophosphates


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