Download - Abhay
ENDOTHELIUM Endothelium is the thin layer of cells that lines the
interior surface of blood vessels and lymphatic vessels forming an interface between circulating blood and lymph in the lumen and the rest of the vessel wall.
The cells that form the endothelium are called
endothelial cells.
endothelial cells in direct contact with blood are
called vascular endothelial cells where as those in
direct contact with lymph are known as lymphatic
endothelial cells.
ENDOTHELIAL DYSFUNCTION Endothelial dysfunction,or the loss of
proper endothelial function,is a hallmark for vascular diseases and is often regarded as a key early event in the development of atherosclerosis.
Impaired endothelial fuctions causing hypertension and thrombosis,is often seen in patients with coronary artery disease,diabetes mellitus,hypertension,hypercholestrolemia,as well as in smokers
INTRODUCTION [NITRIC OXIDE]
Nitric oxide is a gaseous material diffuses across cell membranes .it is a free radical[ie.it has an unpaired electrons in the valence shells]that is why it is very reactive and participates in many chemical reactions trying to loose the extra electron to or gain the missing electrons from other cell molecules leading to their damage,that explains why nitric oxide reacts with many substances inside the body and is consumed quickly at the site of its production.
NITRIC OXIDE
A chemical compound with formula no is a free radical gas.
It is first identified as endothelial derived releasing factor.[EDRF]
At high concentration fight against infections organism and cancer cell.
At lower concentration helps in regulating the circulatory and central nervous system.
NITRIC OXIDE-MAIN POINTS
Nitric oxide differs from other neurotransmitter and hormones in a way that it is not regulated by storage release or targeted degradation.
NO doesnot require receptor for its action when synthesized immedietely utilized.
Calcium calmodulin is necessary for nitric oxide synthesis
NITRIC OXIDE ANDS ITS METABOLITE
Excessive production of NO and its metabolite peroxynitritrite is linked to the pathogenesis of some neurodegenerative diseases.
This is due to the fact that peroxynitrite causes mitochondrial damage and failure of the respiratory electron transport chain.[oxidative phosphorylation]to take place.this leads to neuronal death.
THE STRUCTURE AND NATURE OF NITRIC OXIDE
Nitric oxide is a diatomic free radical consisting of one atom of nitrogen and one atom of oxygen.
Lipid soluble and very small for easy passage between cell membrane.
Short lived usually degraded or reacted within a second.
Natural form is gas.
TYPES OF NITRIC OXIDE SYNTHASE
The human and mouse genome contains 3 different genes encoding nitric oxide synthases.
nNos[orNOS-1]neuronal nos found in neurons. iNos[orNOS-2]inducibleNOS expressed in
astrocyte and microglia of the cns in addition to macrophages and neutrophils.2
eNOS[orNOS-3]found in the endothelial cells that lining blood vessels.all types of NOS act on arginine with the aid of molecular oxygen and NADPH to produce nitric oxide and citrulline.
INDUCTION OF NITRIC OXIDE
Platelet-derived factors,shear stress,acetylcholine,and cytokines stimulate the production of NO by endothelial nitric oxide synthase [eNOS].
eNOS synthesizes NO from the terminal guanidine-nitrogen of l-arginine and oxygen and yields citrulline as byproduct
NO production by eNOS is dependent on calcium-calmodulin and other cofactors.
MEDICAL USE
Neonatal use-nitric oxide are used in critical care to promote capillary and pulmonary dilation to treat primary pulmonary hypertension in neonatal patients.
Antianginal use-nitric oxide is considered an antianginal drug.it causes vasodilation, which can help with ischemic pain known as angina by decreasing the cardiac workload.
ROLE OF NITRIC OXIDE No in the nervous system No in the circulatory system No in the immune system No in the digestive system No in the reproductive system. No in the gene toxicity. No in the apoptosis.
IMPORTANT FUNCTIONS OF NITRIC OXIDE
Nervous system when nitric oxide is formed in nerve cells,it can stimulate the brain and modulate many functions,from behaviour to git activity.
Shock if too much nitric oxide produced,it can dilate blood vessels dropping the blood pressure.
Infections huge quantities of nitric oxide are produced in whole bloodcells to kill invading bacteria and parasites.
ROLE OF NITRIC OXIDE
Wbc use nitric oxide to defend the body against tumors.research are running now to investigate whether it can be used to stop the tumour growth.
Increased levels of nitric oxide,thus widening blood vessels and increasing blood flow.
Nitric oxide plays an important role in the maintenance of healthy blood pressure and,in turn,cvs.
PENILE ERECTION
The vasodilatory effect of no,in turns also plays a role in development and maintenance of penile erection.vasodilation of blood vessels supplying the corpus cavernosum results in more blood flowing in and, hence erection.this is the bilogical basis of sildenefil[viagra].
It inhibit the enzyme phosphodiesterase pde5,which lowers the Cgmp concentration by converting it back to gmp
ROLE OF NITRIC OXIDE IN DIGESTIVE SYSTEM
No is used in adaptive relaxation. No promotes the stretching of the
stomach in response to filling. When the stomach gets full stretch
receptors trigger smooth muscle relaxation through no releasing neurons.
NITRIC OXIDE SUPPLEMENTS BENEFITS
BETTER VASODILATION IMPROVED METABOLISM AND
RECOVERY. ENHANCED PERFORMANCE INCREASED MUSCLE MASS
BLOOD PRESSURE CHANGES STOMACH PROBLEM ELECTROLYTE IMBALANCES MINERAL DEFICIENCIES DECREASED DOPAMINE LEVELS
FOOD RICH IN NITRIC OXIDE
Pepper-known as capsaicin is found in peppers.
Dark chocolate Tofu-Isoflavones are chemical
compounds found in soya protein.