The main hormones of the pancreas that affect blood glucose include insulin, glucagon, somatostatin, and amylin.

1. Mr. Abhijit Bhoyar
Assistant Professor
Department of
Part-II
REGULATION
OF BLOOD GLUCOSE
Child Health Nursing
CARBOHYDRATE
Stages of maintenance of blood glucose level

2. Specific Learning Objectives
At the end of the lecture, the students will be
able to
• Describe the stages of maintenance of blood glucose
level.
• Explain the response to low blood glucose in the
fasting state.

3. Stages of maintenance of blood glucose
level

4. Absorptive stage
• Absorptive stage starts from feeding and lasts upto 3-4
hours after meal.
• During this phase following activities takes place with
regards to glucose.
• Dietary glucose to liver and then to most tissue.
• Glucose is used as a fuel by most tissues.
• Excess of glucose is stored as glycogen in liver and
muscles.

5. Post absorptive phase
• The post absorptive phase lasts for about 16-18 hours
after the absorption(3-4hours after meal) is completed.
• The main activities necessary with regards to glucose
are as follows:
• Lever glycogenolysis become the major source of
blood sugar.

6. Cont….
• Muscle use its glycogen stores for energy.
• Gluconeogenesis starts gradually and peaks about 24
hours after the last meal.
• Glycogenolysis starts declining after 16-18 hours and
by about 24-30 hours is negligible.

7. Starvation
• After about 1-11/2 day of the starvation,
gluconeogenesis is the main source of glucose.
• Fatty acids mobilized from adipose tissue become an
alternate fuel for energy for most tissue.
• Lactate and glycerol are reutilized for
gluconeogenesis.

8. Cont….
• ATP produced in fatty acid oxidation is used in liver for
gluconeogenesis and other body functions.
• High rate of hepatic gluconeogenesis continues for
few days in early starvation.

9. Prolonged starvation
• If starvation continues further beyond 2-3 days and
extend into weeks, hepatic gluconeogenesis decrease
and gluconeogenesis in kidney becomes more
significant.
• Protiens in muscle are broken down to provide
gluconeogenic amino acids.

10. Cont…..
• Fats are the energy source of most tissue.
• If starvation continue beyond without any feeding, lipid
stores are also depleted and several associated
complication, like ketoacidosis, dehydration, etc., occur
ultimately death follows.

11. Response to low Blood Glucose In the
fasting state
• There will be decreased blood glucose levels.
• This stimulates the secretion of Glucagon from
pancreas.
• The Glucagon released into the blood will stimulate
hepatic glycogenolysis and gluconeogenesis, there by
increasing the blood glucose levels.
• Once the blood glucose levels raises to the normal
levels, the stimulus for the release of Glucagon will
diminish.

12. Response to elevated blood Glucose
In the post prandial state (after a meal)
• Remember there are two separate signaling events
• First signal is from the ↑ Blood Glucose to
pancreas
• To stimulates insulin secretion in to the blood stream
• The second signal from insulin to the target cells
• Insulin signals to the muscle, adipose tissue and liver
to permit to glucose in and to utilize glucose
• This effectively lowers Blood Glucose

13. Role of Liver and Extrahepatic Tissues
• GLUT-2 is freely permeable to glucose and is the main
hepatic glucose transporter ( None insulin dependent).
• GLUT-4 is main glucose transporter of extrahepatic tissues
i.e muscle, adipose tissues, etc. ( insulin dependent).
• Hence,the glucose uptake from blood by extrahepetic tissues
is regulated by insulin.
• This is become rate limiting step in glucose utilization in the
absence of insulin.
• But the glucose uptake by liver is independent of insulin.

14. Role of Hexokinase and Glucokinase
• Liver has glucokinase and hexokinase while most
extrahepetic tissue have only hexokinase.
• Hexokinase is saturable, has low Km for glucose and is
product feed back inhibited.
• Glucokinase is non-saturable , has high Km for
glucose and not product feed back inhibited.

15. Cont….
• Liver continues to have high glucose uptake during
hyperglycaemia.
• Extrahepatic tissue is product feed back inhibited due
to accumulation of glucose-6-phosphate even though
insulin is present.
• So at high blood glucose concentration, liver has a net
uptake of glucose.
• But it is net producer of glucose at low or normal blood
glucose concentration.

16. Summary
we have discussed about stages of maintenance of
blood glucose level, response to low blood glucose in the
fasting state.

17. Expected Questions
Short
• Describe the stages of maintenance of blood glucose
level.
• Explain the response to low blood glucose in the
fasting state.