BIOPHYSICS N°15 (FILL)

The endothelial cells, lining blood vessels, respond to certain stimuli, such as

acetylcholine or bradykinin by secreting .............

•NO

Lipoxygenases found in several human tissue convert arachidonic acid into ..........

Leukotrienes

The extremely reactive .......... can attack almost all molecules present in human cells,

initiating free-radical chain reactions.

Hydroxyl radical

In O2*- is generated by or close to the vascular endothelial cells, it can oppose the

vasodilator of NO, that is, O2- can act as a ..............

Vasoconstrictor

In some forms of ............. excessive infiltration and

activation of neutrophils may contribute to severe lung injury.

Acute respiratory distress syndrome

Two of the may toxic aldehydes that can be product by peroxide decomposition are ............ and the even more noxious ............

MDA, 4-hydroxynonenal

In humans ............. is the only enzyme known to require selenium for its activity.

GSM-Px

................ rapidly decomposes H2O2 to water and oxygen.

Catalase

.............. relaxes the smooth muscle in the vessel wall, causing vasodilatation and a

drop in blood pressure.

NO•

Much of the tissue degeneration that occurs after excessive exposure to ionizing

radiation is due free-radical chain reactions started by .............

Hydroxyl radical - •OH

The body manufactures superoxide radical by adding ............. to an oxygen

molecules.

One electron

O2*- serves useful purposes in the human body. Lymphocytes and fibroblasts may

constantly generate small amounts of O2*- as ..............

Growth factor

In chronic granulomatous disease, an inborn defect in one of the components of ................ renders the enzyme ineffective, so that certain strains of engulfed

bacteria are not efficiently killed

Superoxide synthase

The inflamed joints of patients with rheumatoid arthritis contain many activated ............... Overproduction of ROS contributes to tissue injury in the inflamed joint.

Phagocytes

............... convert superoxide to H2O2.

superoxide dismutase

The reaction of superoxide-dependent decomposition od hydrogen peroxide is known

as .............

Haber-Weiss reaction

The reaction of the transition metal decomposition of hydrogen peroxide is known as ..............

Fenton reaction

The meaning of the acronym PUFAs is .............

Poly unsaturated fatty acids

The fluorescent granules of .............. that accumulate in old cells contain

products of the reaction of proteins with aldehydes.

Age pigments

The reaction between the lipid radical and oxygen yields .............

Peroxyl radical (ROO•)

Two peroxyl radicals can react with each other to produce .............

Singlet oxygen

............. can readily decompose lipid hydroperoxides

Glutation peroxidase

Sunlight and porphyrins may interact to generate ..........

Singlet oxygen

The arachidonic acid is the source for the synthesis of ..............

Prostaglandins and leukotrienes

.............. prevents platelets from adhering to the vascular endothelium

Prostacyclin

Glutathione reductase reduces GSSG back to GSH at the expense .............

NADPH oxidation

α - tocopherol has ............ whose hydrogen atom can be easily removed

Hydroxyl group

Epinephrine, norepinephrine and dopamine react with ............. to form superoxide.

Oxygen

Thromboxane A2 promotes ............... aggregation and constricts blood vessels.

Platelet

O2- react with NO to produce ..............

NO2• + •OH