ACTIONS OF THE ESTROGENS of myometruium. (ii) prohfera Development or sexual hairs and acne in girit is probably due

Respectively Line A is the more important of the two paths. This table should be compared with fig 5.9.5. ACTIONS OF THE ESTROGENS of myometruium. (ii) prohfera Development or sexual hairs and acne in girit is probably due to apdtogens in them (2) Drmorphic behanor = behavior peculiar to sex of the species, e g .dog raises hind limb while maturating white fertile dog makes semisquatting posture. For descriptive purposes, they (the actions of E) can be divided into - (a) on sex Organs. (b) On other sndocrinal glands, (c) On metabolism. These actions are listed in the above table (table 6 102) The table (6.102} mentioned metabolic effects have assumed great importance with the introduction of the oral contraceptive pills The standard oral contraceptive pills Contain both estrogen and progesterone. Till the early 1970s, the proportion of estrogen was somewhat greater in those pills, as a result, coronary heart disease, venous thrombosis, high blood pressure, worsening of diabetes, Io mention some, used to develop among the users of the contraceptive pills For- all these reasons, today the proportion of estrogen has been greatly reduced in the individual pills. Mechanism of action (at molecular level] acts like a typical steroid Hormone and it (the estrogen) penetrates the Cell membrane of the target cells (being steroid it should eider past through (he cell membrane) Within the cytoplasm, it combines with the cytoiol receptorD the hormone receptor (HR) complex is formed and the HR then enters the nucleus within the nucleus it attaches with the DNA molecules stimulation of the DMA occurs to synthesize more RNA new proteins (enzymes) are produced Action on DNA also stimulates mitosis As a result, both hyperplasia and hypertrophy of target organs (myomerium, indometrium, breast) can occur as well as production of CBG and angiotlensinogen rise. Carriage and metabolism. This concentration of estradtol in blood varies between 20 to 60 pg per ml. The estrogens combine with specific plasma proteins (chiefly albumin, but it can combine with 6 globulin also), a little of the estrogen remains free, but only the free estrogen! is active Removal of estrogens from the body Estradiol is largely converted into estroae and estriol in the liver. These metabolites, esiione and estriol are conjugated in The liver with glucurcnrc acid (and also sulphate radicals) and rendered water soluble and excreted via the urine Urinary metabolites of the estrogen can be measured by the well known kober-Brown' method Other routes of •Btrogen removal include fecea and some yet unknown routed Determination of estrogenic status Before the introduction of radioimmunoassay (RlA), Koboer Brown method was the chief method of determination of estrogenic status' in a woman It was an unsatisfactory method, because only 70% of the body estrogen is excreted via unne RtA method of plasma estrogen exhumation has greatly improved the picture Estrogen and cancer. Exogenous estrogen (E) given far treatment purpose* may cause cancer. Thus E is sometimes administered in menopausal women to ward off some ill effects of menopause. But These women become susceptible to utenne cancer Oral contraceptives administration containing E are suspected to be associated with the risk of development of breast cancer. There are many reports, suggesting a link between exogenous E and various other cancers Neuroendocrinology Role of estrogen and progesterone As slated earlier (chap I. sec VI). the subject 'Neureondocrmotegy' deals with an area of physiology which is common To both the central nervous system (CNS), particularly brain and the endocrine glands In short, neuroendocrinology represent! an area where the CMS and endocn-nology overlap it hat been estimated that in the rats at alas 60% of progesterone ib utilized by the Bram At lust in enpen-rnental animals, seen behavior ( SB). sbx receptivity (SR) of the females are hormone dependent and the hormones m question are the female sex steroids (FSS) and the pituitary gonadotropins It also appears that the mechanism by which the FSS cause The SB and SR. m the females involves the activity of some neurotransmitters (to be specific, biogeruc amines like noradrenalin, NA, 5 hytiroiytryplamine. 5 HT and may be even dopamine. DA) in venous regions of The brain, notably the hypothalamus. The picture is very far from clear and full of controversies Yet a tentative picture may be as follows* For details, see the seminal article of. McEwen. B S & Parsons, B (1562] Gonadal steroid action on the Bram neurochemistry end reuropharmacology. Ann Rev Pharmaco! b Toncol 22.555-98 1 LH suite is produced by the +ve feed back effect of estrogen (E) 2. LH surge precedes the SB and SR in female rats (Recall LH surge causes the ovulation and the cortus wttf bfl fruitful,i.e. cortus will lead to conception, only when it is made around the tima of avulation Thare fore, leleoiogic principle demands that the female should have the maxi - mai lex drive and sex receptivity during LH surge) Recall further that the sex dive and sex receptivity in female animals are hormone dependent and are thus cychc At other times the female antmals show no SB or SP 3 E administration must be followed by progesterone (P) administration in animals otherwise SB or SR remain weak P alone is however useless. Presence of P Is also essential for termination of SB and SR 4 It Is possible, that FSS cause changes in the level of neurotransmitters of hypothalamus and other arias of bran and