steroid biosynthesis

Question 1

Progestins

Answer 1

progesteron

synthesized in adrenal glands, ovaries, testes

distributed to uterus

mediates implantation and maintenance of pregnancy

Question 2

Glucocorticoids

Answer 2

cortisol cortisone, corticosterone

synthesized in adrenal glands, distributed to a large number of tissues and organs (muscle, liver)

increases blood pressure and Na uptake in kidneys

mediates response to stress by increasing protein catabolism and gluconeogenesis and reducing inflammation

Question 3

mineralocorticoids

Answer 3

aldosterone
11 deoxycorticosterone

made in adrenals, distributed to kidney tubules, colon, and parotid gland, increases Na/H20 retention, K excretion and blood pressure

Question 4

Estrogens

Answer 4

estradiol and estrone

made in ovaries (major), placenta, adipise tissue
distributed to primary and secondary reproductive organs
mediates feminization, estrous cycle

Question 5

Lypophilic signal molecules

Answer 5

steroid hormones:

progesterone, estradiol, testosterone, cortisol, aldoesterone, vitamine D

theyroid hormone– thyroxine

retinoids, retinol, retinoic acid

small lipophilic molecules = steroids

Question 6

i am a peptide that activates expression of desmolase

Answer 6

ACTH: adrenocorticotopic hormone

secreted during stressful situation like hypoglycemia, cold, and exercise

from pituitary gland but turned on by corticotropin releasing hormone from hypothalamus

hypothalamus –> cotricotropin releasing hormone —> pituitary —> ACTH —-> adrenals —> cortisol release

Question 7

i am a peptide that increases activity of desmolase

Answer 7

LH

hypothalamus –> GnRH –> Pituitary –> LH —> desmolase stimulation of activity

Question 8

i am a peptide that actives the enzyme aromatase

Answer 8

FSH

promotes spermatogenesis in men
stimulates menstruation in women

Question 9

Someone is suffering from hypertension and low cortisol

what enzyme is effected

Answer 9

11-beta-hydroxylase, active in both aldosterone and cortisol production pws

Question 10

Someone is suffering from a loss of sex steroids AND cortisol

what enzyme is affected

Answer 10

17-alpha-hydroxylase

Question 11

someone is suffering a defect in 3 beta hydroxysteroid dehydrogenase, which lipophilic compounds are prevented from being synthesized?

Answer 11

all of them EXCEPT FOR ESTRONE

Question 12

aldosterone

Answer 12

promotes na/h2o retention
reduced levels = too much salt
excessive levels = conn syndrome, increased blood volume, hypertension

Question 13

cortisol

Answer 13

also known as hydrocotisone

anti inflammatory and autoimmune properties

stimulates breakdown ofm uscle, gluconeogenesis and glycogen synthesis

Question 14

Conn syndrome

Answer 14

elevated levels of aldosterone, increased blood volume and hypertension follow

Question 15

Cushing syndrome

Answer 15

elevated levels of cortisone

increased fat on face and trunk

can be caused by tumors in the pituitary or adrenal tumors or too much administration of cortiosteroids

effects ACTH feedback system

Question 16

glucocorticoids and immune functioning

Answer 16

like cortisol

inhibits immune system by inducing i-kbalpha inhibitory protein. necessary for IL-2 synthesis, so decreased clonal expansion of B lymphocytes

promotes T cell apoptosis

inhibits both humoral and adaptive branches

Question 17

mineralcorticoids target tissues….

Answer 17

kidneys, colon, parotid gland

contain a receptor that has equal affinity for mineral as glucocorticoids

because they want to avoid Na/Water retention, they must metabolize cortisol further via 3-beta-hydroxysteroid dehydrogenase

Question 18

Cortisol

Answer 18

has affinity for minteralcorticoid receptors 100 time ore concentral than mineralcorticoids, so target tissues further metabolize it to cortisone, a compound with a much less affinity

REAL LICORICE CAN LEAD TO HYPERTENSION BECAUSE IT INHIBITS 3-beta-HYDROXYSTEROID DEHYDROGENASE

Question 19

Vitamin D

the effects are attributed to its

Answer 19

active form: calcitriol

Question 20

Vit D2

Answer 20

ergocalciferol

Question 21

Vit D3

Answer 21

cholcalciferol

Question 22

where are VD3 and VD2 found?

Answer 22

fish, eggs, plants, vitamin d fortified foods

Question 23

Vit D is produced

Answer 23

through diet or through UV rays

Question 24

Calcitriol

Answer 24

active form of VD, derived from VD2 and VD3

also known as 1,25-dihydroxycholcalciferol

Question 25

V D deficiencies related to

Answer 25

lung diseases, autoimmune diseases, malabsorption, cancer, infections, mental sickness

osteomalacia, rickets, bone stuff

Question 26

cholcalciferol

Answer 26

cholecalciferol inactive form of VD3

derived from 7-dehydrocholesterol via UV irradiation in the skin

in intestinal cells from ergocalciferol (Vit D2)

Question 27

7-dehydrocholesterol

Answer 27

produced in skin

UV rays break B ring —> cholecalciferol

Question 28

ergocalciferol

Answer 28

in intestinal cells, Vit D2 —> cholecalciferol

Question 29

25 hydroxylase

Answer 29

in liver it hydroxylates cholecalciferol D3 to 25-hydroxycholecalciferol

Question 30

1-alpha-hydroxylase

Answer 30

in the kidneys this enzymes converts 25 hydroxycholecalciferol to 1,25 dihydroxycholecalciferol

Question 31

calcitriol in the body?

Answer 31

stimulates intestine to absorb calcium and phosphate

increases kidney absorption, promotes calcium resorption from the bone

resulting effect is an elevation in blood Ca and phosphate levels

PTH and calcitonin are peptide signals

Question 32

common inherited defect that leads to salt wasting, hypotension, hyperglycemia due to INCREASED PRODUCTION of cortisol.

causes virilism in women due to increased flow of intermediates into adrenal androgens

Answer 32

21-hydroxylase

Question 33

11 beta hydroxylase deficiency

Answer 33

hypertension due to increased accumulation of 11 deoxycorticosterone