انت هنا الان : شبكة جامعة بابل > موقع الكلية > نظام التعليم الالكتروني > مشاهدة المحاضرة
الكلية كلية الطب
القسم الادوية
المرحلة 3
أستاذ المادة نسرين جلال محمد البياتي
6/17/2011 8:56:17 PM
Histamine
Is biogenic amine
-mediator in inflammatory & immune process
Histadine histamine
-in mast cell & basophil
-free active , storged is inactive
-released due to:
Allergy , trauma , proteolytic E, snake venum , insect bite, bee sting ,
basic drug (morphine)
H1 : on smooth muscle, endothelium, and CNS tissue
**Causes vasodilation,
bronchoconstriction,
separation of endothelial cells
pain and itching
the primary receptors involved in allergic rhinitis symptoms and motion
sickness.
H2:
Located on parietal cells
**stimulate gastric acid secretion
H3 : Found on CNS and lesser peripheral nervous system
release: histamine,neurotransmitter**Decreased
acetylcholine,
norepinephrine,
serotonin
small , thymus , bone marrow , eosinophil , basophils Found in the : 4 Hi
ntestine
chemotaxis**Plays a role in
ST. H1 R
- Bronchoconstriction
- Contraction & seperation of vasc endothelium lead to edema due to
Transudation of fluid
-Dilata venules & arteriols produce redness & hypotension
-contraction of s.m. in gut increasing motility then producing diarrhea
ST. H2 R
- Gastric & pepsin sec ulcer
- HR & myocardial contraction
ST. H3
-act as -ve feed back mechanism
Inhibit histamine synthesis
ST. H4 R
Modulate production of Eosino & Neutro
Triple response of lewis
1- Flush : dilate venules
2- wheal : edema
3- flare : arteriolar dilatation
Histamine Not used orally metabolized by histaminase
Physiological functions of histamine
1-Immidiat allergic reaction
2-anaphylactic reactions
3- tissue injuries
4-inflammatory reactions
5-gastric acid secretions
6-chemotaxic of wbc
Mechanism of action
histamine Histamine exerts its actions by combining with specific cellular
. G- protein coupled receptor:receptors
- H1 : IP3 & DAG & Ca release
-H2 : cAMP
-H3 & 4 : Ca influx & cAMP
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Type
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Location
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Function
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H1 histamine receptor
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Found on smooth muscle, endothelium, and central nervous system tissue
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Causes vasodilation, bronchoconstriction, bronchial smooth muscle contraction, separation of endothelial cells (responsible for hives), and pain and itching due to insect stings; the primary receptors involved in allergic rhinitis symptoms and motion sickness.
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H2 histamine receptor
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Located on parietal cells
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Primarily stimulate gastric acid secretion
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H3 histamine receptor
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Found on central nervous system and to a lesser extent peripheral nervous system tissue
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Decreased neurotransmitter release: histamine, acetylcholine, norepinephrine, serotonin
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H4 histamine receptor
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Found primarily in the basophils and in the bone marrow. It is also found on thymus, small intestine, spleen, and colon.
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Plays a role in chemotaxis
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المادة المعروضة اعلاه هي مدخل الى المحاضرة المرفوعة بواسطة استاذ(ة) المادة . وقد تبدو لك غير متكاملة . حيث يضع استاذ المادة في بعض الاحيان فقط الجزء الاول من المحاضرة من اجل الاطلاع على ما ستقوم بتحميله لاحقا . في نظام التعليم الالكتروني نوفر هذه الخدمة لكي نبقيك على اطلاع حول محتوى الملف الذي ستقوم بتحميله .
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