Estrogen
CHEMISTRY:
- C18 steroids
- Secreted as oestradiol
SOURCE:
- Theca and granulosa cells of the Graafian follicles and corpus luteum
- Adrenal cortex
- Aromatase enzyme associated with the conversion of androgen to oestrogen in the growing ovarian follicle
- Post menopausal estrogen production is due to Peripheral aromatization of androstenedione
AMOUNT SECRETED:
- 50 mcg daily
- Plasma oestradiol level rises 6–7 days before ovulation from to the peak level of 300–600 mcg about 2 days before ovulation and approximately 24 h before the LH peak (level up to 350 pg/mL). Thereafter, the oestradiol concentration falls to 150–200 mcg daily, but a small rise is seen again in the mid-luteal phase.
OESTROGEN IN PREGNANCY:
- Oestradiol, is 10 times as potent as oestrone, is present during reproductive period.
- The placenta is the main source of oestriol.
- Each cycle produces 10 mg of oestradiol.
ACTIONS:
- Feminization and secondary sex characteristics
- Texture of the female skin
- Hair and the shape of female form
- Specific action on the genital tract
- Vulva and vagina
- Development
- Vascular & Epithelial stimulation
- Cornification of the superficial layers of the vagina
- Deposition and metabolism of intracellular glycogen in the vaginal epithelium
Uterus
- Causes myohyperplasia of the myometrium and cervix
- Increases vascularity.
- Regenerates endometrium after menstruation
- Proliferative (preovulatory) growth of the endometrium.
- Stimulant effect on the glands of the endocervix & mucous secretion.
Fallopian tubes:
- Stimulates the tubal musculature
Breast:
- Hypertrophy of the ductal and parenchymal tissue
- Increase vascularity
- Areolar pigmentation
- Supress lactation(large dose)
Other endocrine glands:
- Suppresses FSH and thyrotropic hormones
- Inhibit ovulation
- Stimulate LH & ACTH
Skeletal system:
- ↑ calcification of bone(adolescent)
- Closure of epiphyses
- Decalcification of bone( post menopausal) occur due to it’s deficiency
- Water and sodium metabolism
- Water and sodium , calcium and nitrogen retention
Blood cholesterol:
- HDL & Triglycerides increases(post- menopausal) under oestrogen influence and is cardioprotective
Exam Question
- Failure of bleeding after withdrawal of oestrogen indicates Uterine factor
- Estrogen replacement for post — menopausal symptoms causes an increase in Triglycerides
- Estrogen administration in a menopausal woman increases the Bone mass
- Oestrogen causes Weight gain, Fluid and water retention, Disappearance of comedones
- Post menopausal estrogen production is due to Peripheral aromatization of androstenedione
- Estrogen dependent conditions are Endometriosis, Endometrial carcinoma & Fibroids
- Functions of estrogen are Synthetic function on endometrium, develop secondary sexual characters in female, Breast enlargement during puberty
- Secretion of estrogen is maximum Before ovulation
- The enzyme associated with the conversion of androgen to oestrogen in the growing ovarian follicle is Aromatase
- Effects of estrogen are Reduces LDL,Beneficial effect on cognition,Reduced osteoclastic activity,Increased osteoblastic activity, Increases Triglycerides & Increases HDL
- Estrogen is Used in HRT
- Estrogen causes Increased risk of breast cancer
- By estrogen administration in a menopausal woman Bone mass is increased
- Estrogen Causes cholestasis
- The success of estrogen and estrogen-like drugs in combating osteoporosis in postmenopausal women may indicate that estrogen Inhibits osteoclastic activity
- Estradiol, Estrone & Estriol are the main form of oestrogen secreted from the ovary
- The amount of estrogen in low dose oral contraceptive pills is 20 micrograms
- Aromatase enzyme is associated with the conversion of androgen to oestrogen in a growing ovarian follicle
- Estrogen action on carbohydrate metabolism Glycolysis increases
- Estrogen is mainly responsible for skeletal maturation
- Major estrogen in normal adult women is Estradiol
- Ethinylestradiol is synthetic estrogens
- Estrogen Causes cholestasis
- Estrogen Used in HRT
- Thromboembolism is due to Estrogen
- Ferning pattern of mucus under influence of Estrogen
- Estrogen deficiency leads to Osteoporosis
- Aromatase produces estrogen from androgen
- Estrogen Beta receptors are found on ovary
- FSH and LH both are inhibited by Estrogen
- Reason for hepatic involvement in oral contraceptives is Estrogen
- Vaginal cornification, Pubic & axillary hair growth & Cervical mucus production are pubertal change due to estrogen
- Estrogen is secreted by Granulosa cells
- Estrogen acts on nuclear receptors
Don’t Forget to Solve all the previous Year Question asked on Estrogen
