Using Grammatical Signals Suitable to Patterns of Idea Development
Insulin presentation
1.
2.
3.
4. Introduction
History
Structure of insulin
Biosynthesis
Transport and catabolism
Degradation
Release of insulin
Effects of insulin
Clinical coorelations
5. INTRODUCTION
Insulin
> protein hormone
> by islets of langerhans
> pancreas
Anabolic hormone
> growth & development
6. HISTORY
• Canadian scientist
(1921)
–Fredrick G. Banting
–Charles H. Best
• extracted insulin
–from dog’s pancreas
7. STRUCTURE OF INSULIN
• Insulin
– Polypeptide hormone
– 51 amino acids
– Two chains
• A chain 21 a.a.
• B chain 30 a.a.
• Held by interchange disulfide
bridges
8.
9. BIOSYNTHESIS OF
INSULIN
Synthesis of Preproinsulin.
Conversion of preproinsulin to
proinsulin.
Conversion of proinsulin to insulin.
10. GENETICS OF INSULIN SYNTHESIS
The proinsulin precursor of
insulin is encoded by the INS
gene
15. CATABOLISM OF
INSULIN
Half life: 3-5 minutes
Major organs of degradation
> Liver.
>Kidney.
>Placenta.
50% of insulin removed in a single pass through
liver.
MECHANISM :
Insulin specific protease.
Glutathione insulin transhydrogenase (Insulinase
25. Effect on carbohydrate
metabolism (contd)
In s u lin in d e p e n d e n t t is s u e s
B r a in
RB C
Te s t i s
K id n e y
R e t in a
In t e s t in a l m u c o s a l c e lls
28. Lipid Metabolism
Metabolism Net effect Effect on important
enzymes
Lipogenesis Increased
DeNovo FA Synthesis Increased Acetyl CoA carboxylase
Avalbility of NADPH
Adipose tissue Increased Provide α-glycerol-3-PO4
Lipoprotein lipase
Lipolysis Decreased Hormone sensitive lipase
Ketogenesis Decreased HMG CoA synthetase
Lipoprotein Increased Utilization of VLDL & LDL
29. Protein Metabolism
Metabolism Net Effect Effect on important
enzymes
Protein Increased RNA polymerase
synthesis Amino acids up take
Protein Decreased Transaminases
degradation Deaminases
30. CELL GROWTH &
DEVELOPMENT
• Promote cell growth and development
• Mediated by
• Epidermal growth factors.
• Platelet derived growth factor.
• Prostaglandings.
38. Insulin shock
High level of insulin.
Fall in blood glucose level.
CNS depression.
50-70 mg/dl CNS excitability
20-50 mg/dl CONVULSION&
COMA
< 20 mg/dl COMA
39. HYPOGLYCAEMIA IN FETUS
OF DIABETIC MOTHER
Maternal blood glucose level.
Transfered through placenta.
Fetal blood glucose level.
o β-cells of fetus secrete insulin.
o Saturation of placenta 30 mmol/L
o Hypoglycaemia
40. REFERENCES
• Lectures on “Endocrinology” by C.J.Baired
MD/PhD
• www.dtu.ox.ac.uk/4-T
• Lectures on “Signaling Through Insulin
Receptors” by Oksana Matveinko
• Wikipedia
• Arthur C.Guyton, John E.Hall, “Textbook Of
Medical Physiology” 11th edition Ch: 78
Page:961-970
• Lectures By MA Hussain & ND Theise “ Stem-Cell
Therapy For Diabetes Mellitus”
41. Contd.
• Robert K.Murray, Daryl K.Granner, Victor
W.Rodwell, “Harper’s Illustrated Biochemistry” 27TH
edition Ch:41 Page: 457
• John T.Hensen, Bruce M.Koeppen, “Netter’s Atlas
Of Physiology” 5th edition Ch:8 Fig. 8.19,8.20
• Robert B.Dunn “Kaplan Medical Physiology USMLE
Step 1 Lecture Notes” Section:9 Ch: 5 Page:
407-413
• Insulin by Dr. Dana Armstrong and
Dr. Allen Bennett King
42. Acknowledgements
• Almighty Allah for giving me
audacity for my each step to its triumphant
completion
My Parents
Head of Biochemistry Department
Dr. Shafqat Nazir
All teachers of biochemistry department
My Friends
Library staff
Projectionist