• Like
Composition Of Saliva 2010
Upcoming SlideShare
Loading in...5
×

Composition Of Saliva 2010

  • 22,008 views
Uploaded on

 

  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
  • A super presentation.
    Are you sure you want to
    Your message goes here
  • send me by email Dr/ Ragaa Salama thanks biancaverbo@yahoo.com my report is on Wednesday...Feb.17 2010...please help me...
    Are you sure you want to
    Your message goes here
  • please give me explanation of this power point immediately ..please please i have report tomorrow..
    Are you sure you want to
    Your message goes here
  • لماذا لايقبل التحميل؟
    Are you sure you want to
    Your message goes here
No Downloads

Views

Total Views
22,008
On Slideshare
0
From Embeds
0
Number of Embeds
1

Actions

Shares
Downloads
414
Comments
4
Likes
7

Embeds 0

No embeds

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
    No notes for slide

Transcript

  • 1. Biochemistry of saliva
    • Objectives
    • Describe the composition of saliva
    • Mention its functions
    Dr/ Ragaa Salama
  • 2. Clinical Highlights
    • Understanding of salivary mechanisms prerequisite for
      • effective treatment of salivary gland dysfunctions
      • modulation of bacterial colonization
      • development of artificial saliva
    Dr/ Ragaa Salama
  • 3. Saliva Definition : Secretions of salivary glands (parotid and submandibular/sublingual) Composition of Saliva : 4 major components 1-mucus that serves as a lubricant. 2-amylase ->initiates the digestion of starch. 3-lingual lipase -> begins digestion of fat. 4-electrolyte solution (Na+,Cl - , K+, HCO3 - -> moistens food. 5-proteins& enzymes: Statherins, Proline-rich Proteins (PRPs), Histatins, Cystatins, Lysozyme, Salivary peroxidase Dr/ Ragaa Salama
  • 4.
    • saliva is hypotonic to plasma
    • -Na+ and Cl- ↓ in saliva than plasma
    • -K+ and HCO3- ↑in saliva than in plasma.
    • - pH changes from being slightly acidic (pH 6-7 ,at rest) to basic (pH 8) at ultimate stimulation ↑ ↑ HCO3- in the saliva
    • -Amylase and mucus also increase in concentration after stimulation.
    Dr/ Ragaa Salama
  • 5. functions of saliva Dr/ Ragaa Salama Salivary Families Anti- Bacterial Buffering Digestion Mineral- ization Lubricat- ion &Visco- elasticity Tissue Coating Anti- Fungal Anti- Viral Carbonic anhydrases, Histatins Amylases, Mucins, Lipase Cystatins, Histatins, Proline- rich proteins, Statherins Mucins, Statherins Amylases, Cystatins, Mucins, Proline-rich proteins, Statherins Histatins Cystatins, Mucins Amylases, Cystatins, Histatins, Mucins, Peroxidases
  • 6. Mucin Functions
    • Tissue Coating
      • Protective coating about hard and soft tissues
      • Primary role in formation of acquired pellicle
      • Concentrates anti-microbial molecules at mucosal interface
    • Lubrication
      • Increases lubricating qualities (film strength)
    • Aggregation of bacterial cells
      • Bacterial adhere to mucins may result in surface attachment, or
      • Mucin-coated bacteria may be unable to attach to surface
    • Bacterial adhesion
      • React with bacterial adhesins, thereby blocking them
    Dr/ Ragaa Salama
  • 7. Amylases
    • digestive function
    • Hydrolyzes starches -> amylose ,amylopectin,Maltose ,glucose,
    • in tears, serum, bronchial, and male and female urogenital secretions
    • role in modulating bacterial adherence
    Dr/ Ragaa Salama
  • 8. Lingual Lipase
    • Secreted by von Ebner’s glands of tongue
    • Involved in first phase of fat digestion
    • Hydrolyzes medium- to long-chain triglycerides
    • Important in digestion of milk fat in new-born
    • highly hydrophobic enters fat globules
    Dr/ Ragaa Salama
  • 9. Statherins
    • Produced by acinar cells in salivary glands
    • Statherins prevent precipitation or crystallization of supersaturated calcium phosphate in ductal saliva and oral fluid
    • Lubricant.
    Dr/ Ragaa Salama
  • 10. Proline-rich Proteins (PRPs)
    • Inhibitors of calcium phosphate crystal growth
    • Present in the initially formed enamel pellicle and in “mature” pellicles
    • Acquired enamel pellicle is 0.1-1.0 µm thick layer of macromolecular material on the dental mineral surface
    Dr/ Ragaa Salama
  • 11. Histatins
    • A group of small histidine-rich proteins
    • Potent inhibitors of Candida albicans growth
    Dr/ Ragaa Salama Cystatins
    • Are inhibitors of cysteine-proteases
    • protective against unwanted proteolysis (bacterial proteases, lysed leukocytes)
    • inhibit proteases in periodontal tissues
    • effect on calcium phosphate precipitation
  • 12. Lysozyme ( LZ )
    • Present in numerous organs and most body fluids
    • Oral LZ is derived from at least four sources
      • major and minor salivary glands, phagocytic cells and gingival crevicular fluid (GCF)
    • Biological function
    • anti-microbial activity by:
    • Inhibition of bacterial adhesion to tooth surfaces
    • Inhibition of glucose uptake and acid production
    • Muramidase activity (lysis of peptidoglycan layer)
    Dr/ Ragaa Salama
  • 13. Salivary peroxidase systems
    • Sialoperoxidase (SP, salivary peroxidase)
      • Readily adsorbed to various surfaces of mouth
        • enamel, salivary sediment, bacteria, dental plaque
    • Myeloperoxidase (MP)
      • From leukocytes entering via gingival crevice
      • 15-20% of total peroxidase in whole saliva
    Dr/ Ragaa Salama
  • 14. Regulation of oral microorganisms by SP/MP Dr/ Ragaa Salama Food Ingestion carbohydrates Stimulation Metabolism H + Recovery O 2 thiols Inhibition Salivary Glands SCN - + H 2 O 2 OSCN - /HOSCN Autoinhibition spontaneous +SP Unstimulated bacteria Inhibited bacteria Active bacteria
  • 15. Other anti-microbial activities of LZ
    • Muramidase activity (lysis of peptidoglycan layer)
    • Cationic-dependent activation of bacterial autolysins
    • Aggregation of bacteria
    • Inhibition of bacterial adhesion to tooth surfaces
    • Inhibition of glucose uptake and acid production
    Dr/ Ragaa Salama
  • 16. Anti-microbial activities of saliva Dr/ Ragaa Salama
  • 17.
    • thiocyanate ions and another
    • is several proteolytic enzymes— most important,
    • lysozyme— that (a) attack the bacteria, (b) aid the thiocyanate
    • ions in entering the bacteria where these ions
    • in turn become bactericidal, and (c) digest food particles,
    • thus helping further to remove the bacterial metabolic
    • support.
    • protein antibodies that can destroy oral bacteria
    Dr/ Ragaa Salama