placental hormones

1

بسم الله الرحمن بسم الله الرحمن الرحيمالرحيم

ورحمته ورحمته السالُم� َع�ليڪم السالُم� َع�ليڪم اللهالله

2

Under Kind Supervision

Dr. K.B. MirbaharProfessor

Department of Animal Reproduction

By:Sajid Aziz Samo

2K8-AR-156

3

Physiology

Dr. Sajid Aziz

OFPLACENTA

4

PLACENTA

An organ characteristic of true mammals during pregnancy,Joining mother and offspring, providing endocrine secretionAnd 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

5

PLACENTAL HORMONESPLACENTAL HORMONES

PROTEIN HORMONES

Equine Chorionic Gonadotropin ( eCG)

Placental Lactogen

Protein B

STEROID HORMONES

Estrogen

Progesterone

6

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

7

EQUINE CHORIONIC GONADOTROPIN ( eCG)

Endometrial cup’s of placenta which secrete equineChorionic Gonadotropin hormone

8

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

FUNCTIONS

CONT…………..

9

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

CONT…………..

10

PLACENTAL LACTOGEN

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

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

FUNCTIONS

COMPOSITION

11

PROTEIN B

Involved in preventing destruction of corpus luteum in early pregnancy

Secrete From Conceptus Maternal recognition of pregnancy

FUNCTION

COMPOSITION

Protein in nature

12

ESTROGEN

Secrete from syncytial trophoblast cells Placental secretion of estrogen differentiate from ovarian

secretion of estrogen

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 the myometrial-suppressing activity of progesterone

FUNCTIONS

13

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.

CONT…………..

14

PROGESTERONE

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 conducive to fetal survival.

FUNCTIONS

15

Placental Hormones

Estrogens Steroids Maintenance of pregnancy

Progestin's Steroids Mimic action of progesterone

Chorionic Gonadotropin

Glycoprotein: α is 96 amino

acids; β is 147Activity similar to LH

Placental Lactogen

Protein of 191 amino acids

Acts like prolactin and GH

Protein B ProteinsPrevent destruction of corpus luteum

in early pregnancy

16