Hypothalamic Hormones & Growth Hormone (PDF)

Dt/ Ahmed osama Hypothalamic Hormones A-regulots Factor:_ 1_ Corticotrophin releasing hormone (CRH): It stimulates the secretion of both ACTH and B- endorphin from the anterior pituitary.(‫)الكورتيزول‬ 2_Thyrotrophin releasing hormone (TRH): It stimulates the release of...

Dt/ Ahmed osama Hypothalamic Hormones A-regulots Factor:_ 1_ Corticotrophin releasing hormone (CRH): It stimulates the secretion of both ACTH and B- endorphin from the anterior pituitary.(‫)الكورتيزول‬ 2_Thyrotrophin releasing hormone (TRH): It stimulates the release of thyrotrophin from the anterior pituitary which stimulates the thyroid to produce thyroxin.(T3/T4) 3- Gonadotrophin releasing hormone (GnRH): It stimulates the release of luteinizing hormone and follicle stimulating hormones.(LH/FSH) 4- Growth hormone releasing hormone (GHRH): It produces rapid elevation in plasma growth hormone levels. 5- Growth hormone inhibiting hormone (GHIH, somatostatin): It has inhibitory effect on the release of growth hormone. In addition it also inhibits the release of glucagon, gastrin and thyrotrophin Octreotide; a synthetic analog of somatostatin, Its half- life is longer than that of the natural compound. Used for acromegaly. 6- Prolactin inhibiting hormone (PIH): It is dopamine and it acts as the physiological inhibitor of prolactin release. Anterior Pituitary Hormones1- Growth Hormone (Somatotropin, GH) Secretion: increases by hypoglycemia, fasting stress and GHRH.✓ Decreases by glucose, corticosteroids and administration of GHIH Control: A- Hypthalamus: (GHRH & SS) B- Ghrelin is a peptide hormone secreted from the stomach. Ghrelin stimulates secretion of growth hormone.‫بيحفز افراز هرمون النمو‬ C-Blood level of IGF-1 ‫بتحفز‬ Dt/ Ahmed osama Physiological effect of growth hormone A-Direct effects Stimulates secretions of insulin-like growth factor-1 (IGF-1) 2 Stimulates lipolysis 3 Increase blood glucose level B-Indirect effects are mediated primarily by IGF-1 1.promote growth of long bones, 2. Stimulates protein synthesis in muscle and other tissues 3.increased protein synthesis and decreased oxidation of proteins 4.by stimulating triglyceride breakdown and oxidation in adipocytes 5.have anti-insulin activity on carbohydrates Dt/ Ahmed osama Growth hormone abnormalities abnormalities A-GH deficiency:_ Pituitary dwarfism:‫التقزم‬ deficiency of growth hormone secretion bafore puberty results in growth retardation ( Main symptoms: Short stature, Absent or delayed sexual development) B-Growth hormone excess:_ Gigantism… ‫التعملق فى االطفال‬ (giantism; excess GH before puberty ): The affected person will continue to grow upwards, as well as outwards; have disproportionately long limbs C-Acromegaly ‫كبار السن‬ (excess GH in adults). Enlargement of bones of the extremities (hands, feet, jaw, and nose) as well as the viscera enlarge Agonist Antagonist ⚫ treatment of Dawarfism Treatment of excess GH Stimulation of growth in children In Turner's Octreotide & Lanreotide (long syndrome acting prepration) Inhibits GH (genetic disorder that affects secretion. females. The main characteristics (Octreotide analog of Somatostatin) include short stature and infertility) To counteract the wasting that occur Dopamine agonists:( bromocriptine in AIDS and cabergoline, inhibit growth Body building by athletes hormone release in up to 50% of Human GH is now produced by acromegalics. recombinant DNA technology, either somatrem (Protropin) or somatropin GH receptor antagonist ex. (Humatrope and others) Pegvisomant(‫)بيقفل الريسبتور نفسه‬ Dt/ Ahmed osama Thyroid-Stimulating Hormone (Thyrotropin, TSH) 1. stimulates growth of thyroid gland 2. increases blood flow to thyroid gland 3. stimulates synthesis and release of T3& T4 from the thyroid. 4. stimulates iodide uptake to differentiate between pituitary and thyroid gland failure. Increase plasma thyroid hormone indicates abnormal function of pituitary while no rise in thyroid hormone indicates thyroid insufficiency.(‫)العالقه طرديه‬ ‫)ارتفاع مستوى هرمونات الغدة الدرقية بعد التحفيز = خلل في الغدة النخامية (قصور الغدة الدرقية الثانوي‬. ‫)عدم وجود ارتفاع في مستوى هرمونات الغدة الدرقية = خلل في الغدة الدرقية نفسها (قصور الغدة الدرقية األولي‬.. Adrenocorticotrophic hormone (ACTH, or corticotropin ACTH acts on adrenal cortex 1. Stimulating the synthesis of Glucocorticoids, Mineralocorticoids & Androgens 2. Stimulates the secretion of cortisol from the adrenal gland 3. In the fetus, ACTH stimulates the synthesis of dehydroepiandrosterone sulfate (DHEA-S) which prepare the mother for giving birth.(‫)مهم فى التحضير للوالده‬ 4. Responsible for the maintenance of adrenal weight( ‫)الحفاظ على حجم الغده‬ ACTH agents and uses 1- ACTH (corticotropin) ‫الهرمون الطبيعى الى الجسم بينتجه‬ 2- Cosyntropin (Cortrosyn) synthetic form closely resembles ACTH with longer duration can be taken monthly( ‫)الشكل الصناعى من الهرمون و بتقعد فتره اطول فى الجسم‬ Used to diagnose adrenal disorders, treat deficiencies (rarely, since it is easier and less expensive to treat with glucocorticoid) ‫بنستخدمه علشان نشخص االضطرابات فى الغده الكظريه‬ ‫ بنستخدمه لعالج نقص الهرمون ولكن حاليا بنستخدم‬glucocorticoid ‫النه ارخص فى السعر واسهل فى العالج‬ Dt/ Ahmed osama