Plasma and plasma protein

Extracellular Fluid :

            The fluid that occupies outside the cells is known as extracellular Fluid. The extracellular fluid is also called ''internal environment'' or “internal sea” because all cells that body live a secluded life in this fluid.

            The total amount of ECF - 14 liters (20% of total body wt).

Composition : 24% water found in the extracellular fluid. Extracellular component of body water (14L)

            i)         25% of the extracellular component in the vascular system - Plasma – 3L.

            ii)        75% of the extracellular component in the outside of blood vessels (Interstitial fluid)

            Another component, Na+, Cl-, HCo3- and nutrient such as glucose, amino acid, fatty acid.

pH :- 7.4

Osmolarity : 290 - 310 mosm/L.

Plasma

Plasma is the fluid or non cellular portion of blood. It is the part of extracellular fluid, and communicates containing in the capillaries.

Plasma is a remarkable solution containing  an immense number of ions, inorganic molecules and organic molecules that are in transit to various part of the body or aid in the transport of other substance. Plasma is the liquid medium of blood about 55-60%.

Volume:

            The normal plasma volume is about 5% body weight or roughly 3500ml (av) in a 70kg man.

#          3L (25% of extracellular fluid volume.

Measurment of plasma volume :

             Indicator used : Plasma volume can be measured by using indicators are -

            a)         Evans blue dye (also called T- 1824)

            b)        Serum albumin labelled with radio active iodine ( ¹²⁵I – albumin ).

Component of plasma  :

            Plasma has 3 parts mainly.

            1.         Water.

            2.         Solutes

            3.         Protein.

Water :

            -           about 95%

            -           Forms a medium for the suspension and transport of protein and gas.

            -           Water is the important for temperature regulation.

            -           It release waste and break down products.

Solutes part : It includes

            Gases : O₂. CO₂, N₂

            Sugars :  Glucose, lactate, pyruvate ctc.

            Lipid : Fat, Lecithin, Cholesterol.

            NPN Substance : Amino acid, urea, Uric acid, ammonia salt.

It addition plasma also contain enzyme hormones, vitamins and pigments.

Function:

            -           Create osmotic pressure.

            -           Important in buffering system.

#          plasma also present in all clotting factor.

Plasma protein :

The protein which remain in plasma is known as plasma protein.

origin-

Albumin, globulin and fibrinogen mainly produce liver.

Gamma globulin is produce extrahepatically in lymph node.

Other cell RE  system, spleen and bone marrow.

Types of plasma protein|-

three types of plasma protein are present.

a) albumin.

b) Globulin ®

                                               

i)                   X- albumin ®

a. α₁ globulin

                                                b. α₂ globulin

            ii) β-Globulin

            iii) γ-globulin ® immunoglobulin ( IgG, IgA, IgM, IgD,IgE).

c) Fibrinogen.

volume:

the quanlity of plasma protein is about 7gm% in which

            -albumin (about 4.0-4.2 gm).

            -globulin (about 3gm).

other,

IgG :    1000mg/dl

            IgA:     200 mg/dl

            IgM:    120 mg/dl

            IgD:     3 mg/dl

            IgE:     0.05mg/dl

Fibrinogen: 200-400 mg/dl

Albumin

            Molecular Weight : 69,000.

            Site of formation : Liver.

            Plasma Level : 3.5-5.0 gm/dl.

            Exchange albumin pool : 4.0-5.00 gm/kg body wt

            Albumin by hepatic synthesis 200 -400 mg /kg/day

Properties:

            Smallest, height plasma protein, exerts about 75-80 % of colloidal osmotic pressure. It has a highest ilectrophoretic mobility. Purtipited by full saturation of ammonium sulphate and soluble in distilled water.

Function:

            -Maintains Colloidal osmotic pressure.

            -Maintains viscosity of blood.

            -It acts as a buffer and regulated acid - base balance.

            -Acts as protein reservoir.

            -It has nutritive function.

Clinical significance:-

            Hypoalbuminemia ( Lower plasma albumin)

is observed in malnutrition. Nephrotic syrdrome and cirrhosis of liver.

            2.         Albuminuria

            3.         Micro albuminuria - risk of renal disease.

Globulins

            Molecular weight  : 90,000 - 1, 30, 000.

            Serum level : 2.6 - 4.1 gm/dl.

            Site of formation : Liver, RE System, Plasma cells and lymphoid nodules.

Properties :

            i)         Electrophoretic mobility is next to albumin.

            ii)        It is more assymetrical than albumin and maintain viscosity.

           

Protein	Plasma concentrationn	Molecular wt	Function
µ1 Globulin	0.3 - 0.5g/dl	--	--
µ1 Antitrypsin	< 0.2 g/dl	54,000	inhibitor of trypsin.
µ1 Lipoprotein	0.2-0.3 g/dl	--	transports cholesterol and phospholipid.
Orosomucoid	< 0.1 g/dl	44,000	Bind with progesterone.
Retinol binding  Protein (RBP)	3 - 6mg/dl	21,000	Transport vitamin A
Thyroxin binding globulin	1-2 mg/dl	58,000	Transport Thyroid hormones.
Transcortin	3 - 4 mg/dl	52,000	Major transporter of steroid hormone.
µ2 Globulin	0.4-0.8g/dl	--	---
µ2 Microglobulin	0.2 - 0mg/dl	8000,000	Antitrypsin and antiplasmin activity
Heaptoglobin	< 0.3 g/dl	90,000	Binds with Plasma free hemo-globin and Prevent its excretion.
Prothrombin	< 0.02 g/dl	63,000	Participates in blood coagulation
Ceruloplasmin	< 0.03 g/dl	150,000	transport of cu, oxidation of Fe2+ to Fe3+
b - Globulin	0.6 - 1.1 g/dl	--	--
b - Lipoprtein	0.2-0.5g/dl	--	transport triacylglycerol cerol and cholesterol.
Transferrin	0.2-0.3g/dl	76,000	transports iron
Hemopexin	<0.1 g/dl	57,000	transports heme
Plasminogen	< 0.05 g/dl	40,000	Forms plasmin, involved in fibrinogen.
g - Globlins	0.8 - 1.8 mg/dl	--	Antibody function.

Immunoglobulin

Clinical Signifiunce :

            -           Hemolytic amemia.

            -           Inflammatory condition.

            -           Emphysema.

            -           µ₁ - A_T deficiency liver disease 

Fibrinogen

            Molecular Wt : 3, 40,000.

            Site of formation : liver and lymphoid tissue.

            Plasma concentration : 0.2 - 0.4 g/dl

Properties :

            It is globulin in nature and more viscous than albumin.

Function :

            -           It is essential for coagulation of blood.

            -           It increase ESR and helps to maintain viscosity of blood.

Fibrinolysis :

The term fibrinolysis refers to the dissolution or lysis of blood clots. Plasmin is mostly responsible to the dissolution of fibrin clots. Plasminogen, synthesized in the kidney, is the inactive precursor of Plasmin. Tissue Plasminogen activator and Urokinase convret Plasminogen to Plasmin

Electrophoresis :

Colloidal Particles carry electrical charge on surface. When an electric current is passed. through the colloidal solution positively and negatively charged particle move to the opposite role. This is known as electrophoresis.

Rate of elecrophore depends on

            i)         Size

            ii)        Amount of charge.

Abnormal electrophoretic pattern :

            1.         Multiple myeloma.

            2.         Acute infection.

            3.         Nephrotic Syndrome.

            4.         Primary immune deficiency.

            5.         µ₁ Antitrypsin deficiency.