Angiotensins Angiotensins II is a octapeptide generated in the plasma from plasma alpha globulin involved in electrolyte, blood volume and pressure homeostasis. Enzyme renin is responsible for the pressor effects, later it became evident that the angiotensin converting enzyme (ACE) which is responsible for the formation of inactive fragments of Angiotensin I to Angiotensin II (potent vasoconstrictor) […]
Platelet activating factors Platelet activating factors is a cell membrane derived lipid (Like eicosanoids) with intense biological activity. Platelet activating factor is a misleading name since it has its effects on a variety of other cells and is an important mediator in allergic, asthmatic and inflammatory responses. It is produced by neutrophils, macrophages, eosinophils, mast
Plasma Kinins in animals Plasma Kinins in animals are local mediators of pain and inflammation. The kinins are a family of small peptide molecules, which include- Bradykinin and Kallidin. Tissue damage, allergic reactions, viral infections and inflammatory events activate a series of proteolytic reactions and liberate bradykinin and kallidin. These agents act locally to produce
“Anti Inflammatory action is produced by inhibition of prostaglandin synthesis at the site of injury. Many other mediators may also play a role in inflammation”
Lipid derived autacoids The 3 main groups of Lipid derived autacoids or arachidonic acid metabolites are: Arachidonic acid is not a circulating compound, nor does it have any intrinsic biological activity. Arachidonic acid is incorporated into phospholipids, which make up the membranes of all cells. Hence, arachidonic acid is present in all cells of the
Serotonin Synonyms: 5-Hydroxy tryptamine / 5-HT / Serotonin / Enteramine Serotonin is an autacoid that is present in the intestines, platelets and brain. 90% of serotonin is present in the intestines hence named as “enteramine” and the rest is present in the platelets and brain. Serotonin is found in wasp, scorpion sting, invertebrates, fruits like banana, pineapple
Antihistamine drugs Antihistamine drugs are drugs which have opposite effect of Histamine. these also known as histamine antagonists or blockers. Classification of antihistamine drugs Classification H1 antagonists based on chemical structure Classification of H1 antagonists based on sedation H1 Antihistamines H1 Antihistamines are histamine antagonist or blocker which blocks or inhibit H1 receptors. Pharmacological actions of
Histamine Histamine is a tissue amine derived from the word histos meaning “tissue”. It is present in animal tissues and certain plants (stinging nettle). This autacoid is a mediator of hypersensitivity phenomenon and tissue injury reactions. It is stored in storage granules of mast cells (tissue phagocytes) and basophils. Tissues rich in histamine are skin,
Drugs Acting On Autonomic Ganglia Drugs acting on autonomic ganglia act on both sympathetic and parasympathetic ganglia without specificity and either (stimulate or inhibit discharges from post ganglionic fibers). These are classified into Autonomic ganglionic stimulating drugs and Autonomic ganglionic blocking drugs. Ganglionic stimulants Ganglionic stimulants do not find much clinical uses. Nicotine is available as
Neuromuscular blockers or skeletal muscle relaxant are drug that act peripherally or centrally to reduce muscle tone and cause paralysis.
