Placental Hormones

‫بسم الله الرحمن‬ ‫الرحيم‬

‫م عَليڪم‬ ‫السل ُ‬ ‫‪1‬‬

‫ورحمته‬ ‫الله‬

Under Kind Supervision

Dr. K.B. Mirbahar Professor Department of Animal Reproduction By:

Sajid Aziz Samo 2K8-AR-156

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Physiology Dr. Sajid Aziz

OF PLACENTA

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PLACENTA An organ characteristic of true mammals during pregnancy, Joining mother and offspring, providing endocrine secretion And selective exchange of soluble blood borne substances Through apposition of uterine and trophoblast vascularized parts

HORMONE A chemical substance produced in the body which has a specific regulatory effect on the activity of certain cells or a certain organs 4

PLACENTAL HORMONES PROTEIN HORMONES  Equine Chorionic Gonadotropin ( eCG)  Placental Lactogen  Protein B STEROID HORMONES  Estrogen  Progesterone 5

EQUINE CHORIONIC GONADOTROPIN ( eCG) COMPOSITION  Glycoprotein (α & β subunits) similar to LH and FSH, and higher carbohydrate contents  α have 92 amino acids and 2 carbohydrates  β have 145 amino acids and 5 carbohydrates  Higher sialic acid.  Cups form 45th day of pregnancy until 85th day of pregnancy.  have a 40,000 Daltons molecular weight  eCG synthesize from syncytotrophoblastic cells  eCG found in both urine and blood

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EQUINE CHORIONIC GONADOTROPIN ( eCG) Endometrial cup’s of placenta which secrete equine Chorionic Gonadotropin hormone

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CONT………….. FUNCTIONS Stimulate ovarian follicles ( some ovulate and some lutinize and produce progestogen which maintain pregnancy  Commercially use for super ovulation  eCG has a primarily luteining and luteotropic and little bit FSH activity  Detection of Pregnancy will helps by eCG  It detects in urine after 8 days of conception by sensitive immunoassay

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CONT…………..  Most important function is to prevent the normal involution of the corpus luteum at the end of sexual cycle  Instead, it causes the corpus luteum to secrete large quantity of sexual hormones (progesterone and estrogen)  These cause the Endometrium to continue growing and to store large amount of nutrients  Exerts an interstitial cell stimulating effect on the fetus to produce testosterone in male fetus  Testosterone secretion during gestation that causes the fetus to grow male sex organs  Testosterone secrete by fetal testis also causes the tactical to descend into the scrotum 9

PLACENTAL LACTOGEN COMPOSITION  Protein in nature with chemical properties similar to prolactin and growth hormone  22,000 to 23,000 Daltons molecular weight  In the ovine with 192 amino acids  Isolation from placental tissue, but can not detect in serum of pregnant animal until the last trimester of pregnancy  More Important As Growth Hormone Not As Prolactin FUNCTIONS Regulate and transport maternal nutrients to fetus and do growth  Play role in milk production. Large quantity present in dairy cow’s and lower in beef cow’s 10

PROTEIN B COMPOSITION  Protein in nature FUNCTION  Involved in preventing destruction of corpus luteum in early pregnancy  Secrete From Conceptus  Maternal recognition of pregnancy

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ESTROGEN  Secrete from syncytial trophoblast cells  Placental secretion of estrogen differentiate from ovarian secretion of estrogen FUNCTIONS  During pregnancy causing enlargement of uterus, mammary glands, female external genitalia and growth of mammary ductal structure  Relax various pelvic ligaments. (provide easier passage of the fetus through birth canal)  In many species, the high levels of estrogen in late gestation induces myometrial oxytocin receptors, thereby preparing the uterus for parturition.  Stimulate growth of the Myometrium and antagonize 12 the myometrial-suppressing activity of progesterone

CONT…………..  Like progestins, estrogens suppress Gonadotropin secretion from the pituitary gland.  Stimulate mammary gland development. Estrogens are one in a battery of hormones necessary for both ductal and alveolar growth in the mammary gland.

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PROGESTERONE FUNCTIONS  Development of decidual cells into the uterine Endometrium (provide nutrition)  Decreasing the contractility of gravid uterus to prevent abortion  Development of the conceptus before implantation  Progesterone helps estrogen to prepare mammary glands for lactation  Progesterone inhibit secretion of the pituitary Gonadotropin LH and FSH. To prevents ovulation during pregnancy.  Suppression of contractility in uterine smooth muscle. This is called the "progesterone block" on the Myometrium.  Support of the Endometrium to provide an environment 14 conducive to fetal survival.

Placental Hormones Estrogens

Steroids

Maintenance of pregnancy

Progestin's

Steroids

Mimic action of progesterone

Chorionic Gonadotropin

Glycoprotein: α is 96 amino acids; β is 147

Activity similar to LH

Placental Lactogen

Protein of 191 amino acids

Acts like prolactin and GH

Protein B

Proteins

Prevent destruction of corpus luteum in early pregnancy 15

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