It is found in mast cells (skin, intestinal mucosa, and lung mucosa) and basophils in blood.

Histamine is immediately released upon synthesis.

H1(IP3, phospholipase C, DAG, Ca)

H2 (increased adenylate cyclase)

H3 (decrease adenylate cyclase )

Allergic response stimulates release of Substance P from the C fibers causes itching and increases capillary permeability.

H1: NO, PGI2 release and gives rapid onset mediated by calcium

H2. relaxes vascular smooth by cAMP and longer lasting.

Triple response; Flush, flare and wheal.

causes constriction of extravascular smooth muscle. Bronchoconstriction and diarrhea

Explain the therapeutic affects of H1 antagonists

Allergic response and have no affect on acute allergic response such as anaphylaxis

sedative and used in sleeping.

Non-allergic rhinorhea (work by blocking muscarinic receptors)

Motion sickness prevention by blocking cholinergic activity

Parkinson's by blocking dopaminergic receptors

Antienematic by blocking dopaminergic receptors

and block Na channels for anesthesia

Sedation.

Dry mouth, urinary retention, and blurred vision due to blocking of muscarinic receptor

CNS excitation mostly for elderly patients.

Tolerance

Gastrointestinal

It is cardiac toxicity and it is caused by the lenghtening of QT and massive de-polarization followed by small repolarization.

It is caused by using astemizole or terfanadine used with erythromycin or ketoconazole.

Caused by decreased release of potassium

Pirezepine: Blocks muscarinic receptor and Ach release from the paracine cells.

Misoprostol: prostaglandin analog

Omeprazole: Covalent inhibitor of H/K pump

Headache, dizziness, nausea.

Gynecomastia (men), glactorrhea (women) and loss of libido (cimetidine)

In elderly people it can cause slurred speech, delirium, and confusion.

Also, causes inhibition of CYP450 which affects oxidation oxidases such as warfarin, phenytoin, sulfonylureas and calcium channel blockers.

These are synthesized in denove in response to antibodies reaction, collagens, thrombane.

The platelet acting factors are produced in platelets, neutrophil, monocytes, eiosinophils, vascular endothelium, and mast cells.

Implantation and pregnancy in-vitro is related with PAF and may be PAF release determines the best embryo for implantation.

PAF is also used in developing the medium for embryo and success rate is 50%

FUNCTIONS ARE INVOLVED IN MOOD, SLEEP, BEHAVIOR, CONTROL OF BP, COGNITION, THERMOREGULATION, PAIN PERCEPTION, NEUROENDOCRINE EFFECTS AND SEXUAL BEHAVIORS.

CONTROLS BP BY WORKING BY SEPLANCHIC, RENAL, PULMONARY, AND CEREBRAL VASCULATURE

5HT2C AND 5HT2A ANTAGONIST

USED FOR PROPHYLACTIC MIGRAINES BY ANTAGONIZING THE VASODILATION NOT USED FOR ACUTE MIGRAINES. INHIBITS DIARRHEA ASSOCIATED WITH CARCINOID RELEASE

SIDE EFFECTS INCLUDE DIARRHEA, PAIN, HEARTBURN, NAUSEA, EUPHORIA, HALLUCINATIONS.

BLOCKS 5HT2A RECEPTOR. BLOCKS VASOCONSTRICTION AND PLATELET AGGREGATION

THIS IS USED FOR REYNAUDS PHENOMENON, HYPERTENSION, AND INTERMITTENT CLAUDICATION.

Ergotamine or dihydroergotamine; give for prodrome migraine headache.

Ergonovine; used for give after delivery to stop bleeding due to postpartum hemorrage.

Bromocryptine is give to the patients with pituatary tumor or accessive lactation due to DA agonist, dyskineasis with parkinson's, and acromegaly.

PGI dialates systemic and renal blood vessels, inhibit platelets aggregation and immune system.

PGE inhibits gastric secretion and induces pain, fever and GI mucus.

Thromboxane constricts system and renal blood vessels and induces platelet aggregation and immune system.

PGF constricts bronchiol and uterine smooth muscle.

PGE1 analogs are misopristol and rioprostil.

PGE2 are Enprostil and arbaprostil.

Dialate blood vessels

They are used for pulmonary hypertension.

epoprostenol, and flolan via IV

treprostinil, Remodulin via continuous subcutaneous.

Also, used for inhibition of platelet aggregation during dialysis and the analogs used for that are carbacyclin and illoprost.

List PGF2 analogs and what are they used for ?

Dinoprostpone, used during first and 2nd trimester abortion. Does it by causing uterine contractions and intravaginally is more effective with almost no side effects.

Another one is alprostadil used for congenital heart surgery in neonates. This one increases blood flow to the lungs and increases pulmonary and systemic heart surgery.

1. LTB4

2. LTC4, LTD4 and LTE4.

Montellukast and zafirlukast are LTC4 and LTE4 competitive antagonists. zileuton is 5-lo inhibitor.

It is used in an addition or as an alternative to corticosteroids or b2 agonists.

Side effects include nausea, headache and upset stomach

The effects are mediated by two receptors B1 and B2.

B2 receptors are used in analgesia by stimulating the thin superficial layer of spinal cord, unmylenated nerves and sensory ganglia. Also, it vasodilate via NO release and direct vasoconstriction.

B1 causes inflammation by causing release of histamine from mast cells and edema by changing the permeability of the membrane.