Endocrinology is a specialty of medicine; some would say a sub-specialty of internal medicine, which deals with the diagnosis and treatment of diseases related to hormones. Endocrinology covers such human functions as the coordination of metabolism, respiration, reproduction, sensory perception, and movement

1. Endocrine Glands
of the Body

2. Various Endocrine Glands of
the Body

3.  Endocrinology is a specialty of
medicine; some would say a sub-
specialty of internal medicine, which
deals with the diagnosis and treatment
of diseases related to
hormones. Endocrinology covers such
human functions as the coordination of
metabolism, respiration, reproduction,
sensory perception, and movement.

4. Types of Hormones
 Proteins, peptides and amino acid
derivatives
– Proteins are large molecules made of
many amino acids
– Peptides are smaller molecules typically
made of a few amino acids
– Amino acid derivatives are molecules
derived from a single amino acid

5. Lipid Hormones
 Steroid hormones
– Derived from cholesterol
– All similar in structure, but small
differences confer different effects
– Similarities responsible for some cross
reactivity
 Eicosanoids
– Derived from arachadonic acid (fat)

6. The hypothalamus
 Integrates information and many functions of
the nervous system
 The hypothalamus controls the function of
the pituitary gland in two ways
 It can secrete releasing hormones that act on
the pituitary to stimulate secretion of
stimulating hormones
 It can also stimulate the release of hormones
from the posterior pituitary via nervous input

7. The Pituitary
 Divided into two halves
 The anterior portion is comprised of
epithelial cells that act primarily as a
glandular structure
 The posterior portion has extensive
innervation and responds to nervous
sytem input from the hypothalamus

8. The hypothalamus and the
Pituitary

9. Table. 10.3a

10. Table. 10.3b

12. Hormones of the Pituitary
 Growth hormone
– Controls growth and glucose metabolism
– Mediated via the somatomedins
 ACTH
– Acts on the adrenal gland to stimulate the release
of cortisol
 Gonadotropins
– Leutinizing hormone- ovulation, secretion of sex
hormones
– Follicle stimulating hormone – development of
follicles and sperm cells

13.  Prolactin – stimulates breasts to
develop milk
 Melanocyte stimulating hormone
– Causes synthesis of melanin

14. Hormones of the Posterior
Pituitary
 Antidiuretic hormone (aka
vasopressin)
– Causes the retention of fluid in the urine
– Combats dehydration
 Oxytocin
– Causes lactation
– Contractions during child birth

16. The Thyroid Gland
 Secretes two hormones that regulate
metabolic rate
– Thyroxine (T4) – contains four iodine
atoms
– Triiodothyronine (T3) – contains three
iiodine atoms
– Insufficient iodine impairs T3 and T4
synthesis

17. The Parathyroid Gland
 Primarily responsible for calcium
homeostasis
 Parathyroid hormone
– Causes increased production of vitamin D
and increased absorption of calcium in
the intestine
– Also causes resorption of calcium from
the bones
– Increased retention of calcium in the
kidneys

18. Regulation of the Thyroid
Gland

19. Clinical Indication
Thyroid Hormones:
Replacement or supplement in hypothyroidism of
any cause
 cretinism- mental & physical retardation in
 children with chronic untreated hypothyroidism
 nontoxic goiter in adults
 myxedema in adults

20. Thyroid Hormones
Hormones (proteins) secreted from the thyroid
gland include:
 Triiodothyronine (T3)
 Thyroxine (T4)
 and Thyrocalcitonin
TSH (Thyroid Stimulating Hormone)
 Is secreted from the anterior pituitary gland in
response to changes in the blood levels of T3
and T4
 Triggers T3, T4 secretion from the thyroid
gland

21. T3, T4- concerned with muscle and nerve
tissue growth
• stimulates protein synthesis
• increases the intestinal absorption of glucose
• increases glycogen synthesis
• mobilizes fatty acids
• decreases serum cholesterol
• increases BMR (basal metabolic rate)
Thyroid Hormones

22. Adverse Effects Related to Overdosing
Symptoms are dose and time dependent and characteristic
of hyperthyroidism and increase in sympathetic tone:
 Mental confusion to psychotic behavior
 Increased blood pressure
 Increased heart rate
 Diarrhea
 Weight loss
 Sweating
 Menstrual irregularities
 Tremors
 Headache
 Nervousness
 Anginal episodes

23. Cautions and Contraindications
Thyroid hormone therapy
 is contraindicated in patients with myocardial
infarction
 is not recommended for weight reduction in
the management of obesity
 should be used with caution in patients
– With cardiovascular disease, diabetes, adrenal
insufficiency
– Who are elderly

24. Antithyroid Drugs
Clinical Indication
Treatment of hypersecretory conditions of
the thyroid in order to:
inactivate overactive tissue
inhibit production of T3 and T4

25. Effects of Hypersecretion
or Hyperthyroidism
May be caused by tumors on the thyroid (thyrotoxic
crisis), pituitary, or hypothalamus
or
Autoimmune disease (Grave’s Disease)
– LATS (long-acting thyroid stimulating protein) not
the same as TSH but same responses occur
Symptoms are dose and time dependent and
characteristic of hyperthyroidism especially increased
sympathetic autonomic tone

26. Antithyroid Drugs
Mechanism of action
Accumulate within the thyroid and destroy
overactive tissue or inhibit the incorporation
of iodine for production of T3 and T4
 Radioactive Iodide (immediate onset)
 Methimazone (requires time to see effect)
 Propylthiouracil (requires time to see effect)

27. Antithyroid Drugs Special
Considerations & Contraindications
 Cross the placenta and affect fetal thyroid
development
 Abrupt discontinuation of iodide may cause
thyroid storm
 Iodide should be discontinued if fever, rash,
soreness in gums & teeth occur
 Iodide-containing drugs are contraindicated in
patients with pulmonary edema
 Radioactive iodide is present in the saliva and
urine 24 hours after dosing

28. Calcium Homeostasis
Parathyroid Hormones
Calcium ions
 Essential for neuromuscular and endocrine
function
 Serum levels strictly regulated by two
polypeptide hormones
– calcitonin (thyroid)
– parathormone (parathyroid)

29. Calcium Homeostasis
Parathormone
Stimulated when serum calcium levels are low
Stimulates bone resorption to mobilize calcium
Increases intestinal and renal reabsorption of
calcium
Calcitonin
Stimulated when serum calcium levels are high
Inhibits bone resorption
No effect on the intestine or kidney
Antagonizes parathormone

30. Calcium Disorders & Treatment
 Hypocalcemia
Parathyroid damage during surgery
Treatment: calcium salts and vitamin D
 Hypercalcemia
Neoplasms, multiple myeloma, renal
dysfunction
Treatment: diuretics to increase the renal
clearance of calcium
calcitonin and bisphosphonates

31. Degenerative Bone Disease
& Treatment
 Osteoporosis
Decreased bone mass
Decreased mineral deposition
Increased bone resorption
Treatment: Bisphosphonates, estrogen
 Paget’s Disease
Hyperactive bone metabolism
Fragile bone and microfractures
Treatment: Calcitonin, bisphosphonates

32. Bisphosphonates
 Alendronate
 Etidronate
 Pamidronate
Poorly absorbed, not metabolized,
excreted
in urine

33. The Adrenal Glands
 Adrenal medulla responsible for the
hormonal fight or flight response
 Adrenal medulla releases epinephrine
(adrenaline) and small amounts of
norepinephrine

34. Fight or Flight Hormones
 Increases breakdown of glycogen to
glucose in the liver
 Increase heart rate
– Increases cardiac output to the tissues
 Increases blood pressure
 Increases metabolic rate in skeletal
muscle, cardiac muscle and nervous
tissue

35. The Adrenal Cortex
 Produces gluccocorticoids
– Cortisol
 Regulates blood glucose levels
 Causes amino acids to be converted to
glucose in the liver
 Cortisol secreted in times of stress to
maintain glucose and energy levels

36. Clinical Indication
Glucocorticoids
Replacement therapy in adrenal insufficiency
(Addison’s Disease)
Interrupt moderate to severe pain associated with
conditions of inflammation
Mineralocorticoids
Replacement therapy in adrenalectomy or adrenal
tumors

37. Glucocorticoids
 Adrenal cortex secretes glucocorticoids
 Typically referred to as steroids
 Regulate the metabolism of carbohydrates
and proteins
 Demand for cortisol rises during stress and
tissue repair (e.g. wound healing)
 Produce and conserve glucose
 Promote protein catabolism and
gluconeogenesis
 Some mineralocorticoid activity i.e., sodium
retention

38. Corticosteroids
Source of steroids-natural & synthetic
cortisone, hydrocortisone, prednisone,
methylprenisolone, triamcinolone, betamethasone,
dexamethasone
Vary in duration of action and potency
Antiinflammatory action
stabilize cell membranes
prevent edema
Systemic use in patients with normal adrenal function
arthritis, collagen disease, rheumatic disorders, respiratory
disease, spinal cord injury
Topical use for skin irritation, rashes, itching

39. Corticosteroids Adverse Effects
Associated with high doses and chronic use
 Exaggeration of steroid symptoms of Cushing’s
disease
mood changes
insomnia
weight gain, obesity
protein catabolism, muscle weakness, wasting
osteoporosis
decreased wound healing
increased infections
fat deposition, moon facies
 Steroid addiction
personality changes- “steroid psychosis”
psychological dependency (falacy)

40. Steroid Contraindications
 Patients with systemic fungal
infections
 Local viral herpes infections
 Topical application to the eyes or
orbital area
 Live virus vaccinations

41. The Pancreas

42.  The pancreas produces insulin and
glucagon
– The primary blood glucose regulatory
hormones
 Insulin produced in the beta cells of
the islets of Langerhans
 Glucagon produced in the alpha cells

43. Insulin
 The primary glucoregulatory hormone
 Elevated in response to increased
blood glucose or amino acids
 Inhibited when blood glucose is low
 Diabetes results from perturbed insulin
metabolism

44. Diabetes
 Type 1- insulin dependent diabetes
– The individual does not produce insulin
 Type II- non-insulin dependent
diabetes mellitus (adult onset)
– The individual does not respond
appropriately to insulin

45. Clinical Indication
Maintain circulating glucose levels sufficient
to promote intracellular glucose transport
and provide a source of energy for cells

46. Pancreatic Endocrine Function
The pancreas secrets two polypeptide
hormones that regulate carbohydrate
metabolism and blood glucose levels
 Insulin
Promotes glucose movement into cells
and carbohydrate storage
 Glucagon
Increases glucose in the blood by stimulating
glycogen breakdown

47. Insulin & Glucagon Secretion
Insulin is secreted by beta cells in response to
elevated glucose levels
• Mobilizes glucose into skeletal, heart, fat cells
• Promotes storage of fat and protein
Glucagon is secreted by alpha cells in response to
low glucose levels
• Stimulates glyocogenolysis (breakdown)
• Mobilizes glucose into the circulation

48. • Defect in beta cell function
• Deficiency in insulin production and
secretion
• Type I DM is insulin dependent
(juvenile diabetes)
genetic predisposition
• Type II DM relative insulin deficiency
(maturity-onset)
aging, improper diet, obesity
Diabetes Mellitus (DM)

49. Diabetes Mellitus
Symptoms
 Persistently high blood glucose levels
 Spill over into high urine glucose (glycosuria)
 Volume of water excreted (polyuria)
 Dehydration and thirst
 Excessive fluid intake (polydipsia)
 Excessive food intake (polyphagia)
 Fat breakdown produces ketosis
 Neuropathy, retinal hemorrhage
 Renal dysfunction
 Atherosclerosis

50. Treatment of Diabetes
Mellitus
Correct the metabolic imbalance with diet
adjustment and administration of
 Insulins
 Oral sulfonylureas
acetohexamide, glipizide, glyburide, tolazamide,
tolbutamide
 Glucose absorption inhibitors
acarbose, miglitol
 Antihyperglycemic drugs
Metformin, troglitazone

51. Treatment of Diabetes Mellitus
Insulin (Type I, II DM)
 Sources: animal or recombinant DNA
 Onset of action varies with each insulin
type
 Provides single peak of glucose activity
 Requires multiple daily doses
 Injected 15 to 30 minutes before meals
 Juice or sugar can reverse hypoglycemia
 Salicylates, beta-blockers, MAOI potentiate
insulin-induced hypoglycemia

52. Treatment of Diabetes
Mellitus
Oral sulfonylureas (oral hypoglycemics)
 Type II DM only
 Enter the beta cells and cause insulin release
 Vary in onset and duration of action
 Delay in onset related to absorption
 Not a substitute for insulin
 Prolonged action sustains hypoglycemia
 Cause gastrointestinal irritation, nausea,
diarrhea, weakness, fatigue, dizziness,
hypersensitivity reactions (rash), elevated serum
liver enzymes, leukopenia, thrombocytopenia &
anemia

53. Contraindications & Drug Interactions
with Oral Hypoglycemics
Contraindicated in patients:
 With a known hypersensitivity
 With complications of fever, ketoacidosis or
coma
 With liver or renal disease, peptic ulcers
 Who are pregnant
Drug Interactions occur because of
 Protein binding displacement
 Liver enzyme inhibition
 Inhibition of glucose metabolism

54. Treatment of Diabetes
Mellitus
Glucose Absorption Inhibitors
 Do not reduce blood glucose levels
 Do not release insulin
 Interfere with dietary carbohydrate digestion
 Delay a peak in glucose absorption after meals
 Are ingested with meals
 Do not impair liver enzymes
 Cause flatulence, diarrhea, and abdominal pain
 Contraindicated in patients with ketoacidosis,
impaired absorption, or hypersensitivity reaction

55. Treatment of Diabetes Mellitus
Antihyperglycemic Drugs
 Do not reduce blood glucose levels or release insulin
 Keep glucose blood level from rising too fast
 Decrease liver glucose production and intestinal
glucose absorption
 Promote smoother distribution of glucose to tissues
 Causes diarrhea, nausea, vomiting and flatulence
 May cause lactic acidosis leading to respiratory and
cardiovascular distress
 Contraindicated in patients with metabolic acidosis,
renal disease or abnormal creatinine clearance

56. The Testes and the
Ovaries
 The testes produce testosterone
 The ovaries produce estrogen and
progesterone

57. Clinical Indication
Female hormones
Replacement therapy in hypogonadism
and menopause, or fertility
enhancement, and adjunctive therapy
for cancer
Prevent ovulation or implantation in the
uterus
Alleviate menstrual disorders in
nonmenopausal women

58. Female Sex Hormones
Estrogens and Progestogens
LH and FSH secreted from the anterior pituitary gland
induce conditions for the secretion of estrogen and
progesterone
Estrogens secreted from developing cells in the ovaries
stimulate
• uterine lining and mammary glands
• motility within the fallopian tubes
• endometrium for implantation of a fertilized egg
Progesterone secreted from the corpus luteum
• completes development uterine lining for implantation
• stimulates mammary ducts for lactation

59. Pharmacological Actions
Contraception
Estrogen and progestogen combinations mimic the natural
secretory cycle so that
• FSH and LH secretions are suppressed
• ovulation is blocked
• cervical mucus is thickened decreasing the possibility of
implantation
Hormone Replacement Therapy (HRT)
Estrogens interact with receptors to reduce
• hot flashes, sweating, muscle & joint aches that occur
during menopause
• bone resorption and turnover that decreases bone mineral
density in osteoporosis
• coronary artery disease by decreasing blood pressure,
LDL- lipoproteins and insulin

60. Estrogen and Progestogens
Adverse Effects
 Nausea
 Vomiting
 Headache
 Dizziness
 Irritability
 Depression
 Fluid retention
 Breast tenderness
 Weight gain
 Thrombophlebitis (pain in legs, groin)
 Double-vision

61. Female Sex Hormones
Contraindications
Use in pregnant women or those with a history of
Thrombophlebitis
Liver disease
Breast tumors
Estrogen-dependent cancers
Undiagnosed vaginal bleeding
Special considerations
Use in women with a history of
Diabetes
High blood pressure
Seizure disorders

62. Male Sex Hormones -
Androgens
Clinical Indication
In men
Replacement therapy in hypogonadism,
delayed puberty, and impotence due to
androgen deficiency
In women
Adjunctive therapy for inoperable breast
cancer and postpartum breast engorgement

63. Androgens Pharmacologic
Action
Anabolic action - Stimulate protein synthesis
– Clinical benefit- Increase body weight and appetite
– Nontherapeutic use- Increase muscle mass and
enhance athletic performance
Erythropoiesis-Stimulate production of RBCs
– Clinical benefit- Reverse refractory anemia
Inhibit tumor growth
– Clinical benefit- reduce pain & swelling in women with
fibrocystic breast disease

64. Adverse Effects
Men may develop Women may develop
 Decreased sperm count Hirsutism
 Increased breast tissue Menstrual irregularities
 Sustained erection Acne
 Tumors Deepening voice
 Addiction syndrome
Men and women
 Jaundice
 Nausea
 Vomiting
 Diarrhea
 Retention of sodium and water
Result from chronic high dose use

65. Androgens Special Considerations
and Contraindications
Contraindications
Men breast or prostate cancer
Pregnant women- virilization of fetus
Special considerations
Blood glucose levels may fluctuate in diabetic
patients
Bruising and localized hemorrhages may
increase in patients also receiving
anticoagulants