1. KIDNEYS BIOCHEMISTRY

2. Two layers: external – cortex, inner – medulla.

3. Functional-structural unit – nephron.
Every kidney – about nephrons.

4. RENAL FUNCTIONS
Excretion of the end products from the organism (formation of urine)
Maintenance of acidic-base balance
Maintenance of water-salt balance
Maintenance of osmotic pressure
-Hormonal activity
rennin synthesis (blood pressure regulation)
erythropoietin (erythrocytes formation),
1,25-dihydroxycholecalcipherol (vitamin D3)
Regulation of blood pressure
Metabolism of proteins, lipids, carbohydrates, energetic metabolism

5. Metabolism in kidneys 80 % of water about 10 % of all oxygen
L of blood/day (25%)
carbs – main energetic material
Active:
Glycolysis
Ketolysis
Transamination and deamination

6. Urine formation Structures responsible for the urine formation:
glomeruli,
proximal canaliculi,
distal canaliculi.
Mechanism of urine formation:
filtration
reabsorption
secretion

7. Mechanisms of elimination:
filtration
reabsorption
excretion

8. Filtration About 120 mL/min or 180 L/day of blood is filtrated.
Takes place in glomeruli.
Substances with molecular mass below 40,000 Da pass through the membrane of glomerulus into capsula.
About 120 mL/min or 180 L/day of blood is filtrated.
Filtration – passive process.
After filtration – primary urine (180 L/day)

9. Filtration is caused by:
-hydrostatic pressure of blood in capillaries of glomeruli (70 mm Hg)
-oncotic pressure of blood plasma proteins (30 mm Hg)
-hydrostatic pressure of ultrafiltrate in capsule (20 mm Hg)
70 mm Hg-(30 mm Hg+20 mm Hg)=20 mm Hg
Hydrostatic pressure in glomeruli is determined by the ratio between diameter of ascendant and descendant arteriole

10. Reabsorption Takes place in proximal and distal canaliculi.
What is reabsorbed? Glucose (100%), amino acids (93%), water (98%), NaCl (70%) etc.
The urine is concentrated (toxins damages the proximal canaliculi)
Reabsorption:
active
passive.
Lipophilic substances - passive.
Na/K АТP-аse is very active

11. Secretion Takes place in proximal and distal canaliculi. Secretion:
Transport of substances from blood into filtrate.
Takes place in proximal and distal canaliculi.
Secretion:
active
passive.
Passive secretion depends on the pH.
What is secreted?
Ions of K, аmmonia, H+
drugs
xenobiotics

12. CLEARANCE Clearance = (C urine/C plasma) * V
Clearance of any substance is expressed in ml of blood plasma that is purified from this substance for 1 min while passing through the kidneys.
About 180 L of primary urine is formed for 1 day, about 125 mL of primary urine for 1 min.
Glucose is reabsorbed completely; clearance = 0
Inulin is not reabsorbed absolutely; clearance = 125 mL/min
If clearance is more than 125 mL/min the substance is secreted actively.
Clearance = (C urine/C plasma) * V

13. REGULATION OF BLOOD PRESUURE BY KIDNEYS

14. The increase of blood pressure
REGULATION OF BLOOD PRESSURE BY KIDNEYS
Inadequate supply of blood to kidneys (decrease of blood pressure, hypovolemia)
Constriction of arterioles
Irritation of juxtaglomerular cells
Rhenin
Angitensinogen
Angiotensin І
Angiotensin-converting enzyme
Secretion of aldosteron
Angiotensin ІІ
Reabsorption of Na and water
Vasocostriction
The increase of blood volume
The increase of blood pressure

15. REGULATION OF BLOOD PRESSURE BY KIDNEYS
The decrease of blood pressure, hypovolemia
The decrease of blood volume in atriums and carotid sinuses
Reaction of volume-receptors
Impulses to hypothalamus
Stimulation of vasopressine formation
Activation of hyaluronidase in kidneys canaliculi
Depolimeralisation of hyaluronic acid
The increase of water reabsorption
The increase of blood volume
The increase of blood pressure

16. MAINTAINING OF ACIDIC-BASE BALANCE BY KIDNEYS
Three mechanisms:
Conversion of two substituted phosphates into one substituted in the cavity of canaliculi
Formation of carbonic acid in the cells with the following dissociation to Н+ and НСО3-
ammonia excretion

17. MAINTAINING OF ACIDIC-BASE BALANCE BY KIDNEYS
Cells of canaliculus
Blood
Cavity of canaliculus
Na2HPO4
Na+
Na+
Na+
Na+
HPO42- H+ H+
NaH2PO4

18. MAINTAINING OF ACIDIC-BASE BALANCE BY KIDNEYS
Cells of canaliculus
Blood
Cavity of canaliculus
NaHCO3
Na+
Na+
Na+ H+ H+
HCO3-
HCO3-
H2CO3
H2CO3
H2O +
CO2
H2O
CO2

19. MAINTAINING OF ACIDIC-BASE BALANCE BY KIDNEYS
Cells of canaliculus
Blood
Cavity of canaliculus
Glutamine
NH3
NH3+H+
Glutamic acid
NH4+

20. Hormonal activity (erythropoietin)
Normal level of oxygen in blood
The increased consumption of oxygen or decreased amount of erythrocytes
The decrease of oxygen level in blood
Formation of erythropoietin by kidneys
Erythropoietin stimulation
Bone marrow
Intensified erythropoiesis
Increased number of erythrocytes
The increase of oxygen in blood

21. Active form of vitamin D -1,25-dihydro-xycholecalci-ferol is formed in kidneys

22. Transparency – transparent
PROPERTIES OF URINE
Amount – mL/day
Poliuria – diabetes mellitus and insipidus
Oliguria – heart failure, nephritis, vomiting, fever
Anuria – kidney failure, acute intoxication by heavy metals
Color – straw-yellow
Pale – poliuria (diabetes insipidud)
Dark – jaundice, concentrated urine
Red – blood available
Green-blue – decay of proteins in the intestine
Transparency – transparent
Cloudy – pus or mucin available

23. Density – 1,003-1,035 g/mL
Increased density – organic or inorganic substances available (diabetes mellitus)
Decreased density – diabetes insipidus
Isostenuria – continuously low density in oliguria (kidney failure)
pH –
Acidic – meat food, diabetes mellitus, starvation, fever
Alkaline – plant food, cystitis, pyelitis

24. PATHOLOGICAL COMPONENTS IN URINE
Hematuria
Causes of hematuria
Infectious diseases – glomerulonephrotis, pyelonephritis, prostatitis, uretritis, cystitis
Stones in kidneys and urinary tracts
Trauma of kidneys and organs of urinary tracts
Tumors of kidneys and organs of urinary tracts – cancer of kidneys, bladder
Macrohematuria
Microhematuria

25. PATHOLOGICAL COMPONENTS IN URINE Proteinuria
Type
Pathophysio-logic features
Cause
Glomerular
Increased glomerular capillary permeability to protein
Primary or secondary glomerulopathy
Tubular
Decreased tubular reabsorption of proteins in glomerular filtrate
Tubular or interstitial
disease
Overflow
Increased production of low-molecular-weight proteins
Monoclonal gammopathy, leukemia
COMMON CAUSES OF
BENIGN PROTEINURIA
Dehydration
Emotional stress
Fever
Heat injury
Inflammatory process
Intense activity
Most acute illnesses
Orthostatic (postural) disorder

26. PATHOLOGICAL COMPONENTS IN URINE
Glycosuria
Physiological:
· Alimentary – (in min after carbohydrate food consumption.
· Emotional (stress).
Pathological:
· Related to hyperglycemia:
· Insular – deficit of insulin (diabetes mellitus, pancreatitis).
· Extrainsular – disorders of thyroid gland, pituitary functions, liver diseases).
· Not related to hyperglycemia – renal glycosuria (normal level of glucose in blood) (renal diabetes).

27. PATHOLOGICAL COMPONENTS IN URINE
Pyuria
Condition where there is pus or too many white blood cells in the urine
Causes:
Infectious diseases of kidneys or urinary tract (chlamydia, gonorrhea, viral infections, mycoplasma, fungal infections, tuberculosis), infection of the prostate
Noninfectious causes
treatment with glucocorticoids
mechanical trauma
kidney stones
tumors (benign or malignant)
Cloudy urine - pyuria

28. PATHOLOGICAL COMPONENTS IN URINE
Bilirubinuria
Bilirubinuria – appearance of bilirubin in urine
Is the result of direct (conjugated) bilirubin in blood
Causes:
mechanical jaundice
parenchimal jaundice
Brown color of urine
- bilirubinuria

29. PATHOLOGICAL COMPONENTS IN URINE
Urobilinuria
Urobilinuria – appearance of urobilin in urine
Causes
overburdening of the liver
excessive RBC breakdown
increased urobilinogen production
a large hematoma
restricted liver function
hepatic infection
poisoning
liver cirrhosis
Brown color of urine
- urobilinuria

30. PATHOLOGICAL COMPONENTS IN URINE
Phenylketonuria
Appearance of phenylpyruvate in urine
Phenylketonuria - genetically determined disease which is caused by an absence or deficiency of phenylalanine hydroxylase
FeCl3 test