Regulation of Blood Sugar

Pancreas exerts most control over glucose concentration in blood by the secretion of 2 peptide hormones:

1.Insulin2.Glucagon

Anatomy & Histology of the Pancreas

• 2 states of nutrient usage:1. Absorptive: nutrients

absorbed from intestine & into cells

2. Post-Absorptive: nutrients NOT entering body & must be made available from body stores

ROLE OF INSULINRegulates entry of glucose & amino

acids into cellsReleased from -cells in Islets of

Langerhans in Pancreas

FEEDBACK LOOPS

LIPASE ACTIVATED

ISLET -CELLS

INSULIN

CATABOLIC ENZYMES INHIBITED GLYCOGEN

INHIBITED

ANABOLIC ENZYMES STIMULATED

CELLULAR UPTAKE SYSTEMS ACTIVATED

INCR. AMINO ACIDS

INCR. GLUCOSE

CCK

RELEASE OF INSULINHigh blood glucose & amino acid levels stimulate the release from pancreasHormone CCK and Parasympathetic Nervous System also stimulates release

High carb diets increase the density of insulin receptors on -cells making them more sensitive to change

Low carb diets do the opposite

EFFECTS OF INSULINGenerally increases the uptake of glucose by cells

MUSCLESIncrease glucose uptakeIncreases amino acid uptake

LIVERStimulates enzymes that make glycogenInhibits enzymes that break down glycogenStimulate enzymes that synthesize fats

ROLE OF GLUCAGONActs in post-absorptive state (catabolic)Made in -cells of Islets of Langerhans in Pancreas

Stimulates the breakdown of glycogen in the liver and other substances into glucose (a.a.’s & lipids)

REMEMBER GLUCOSE DOES NOT EASILY ENTER CELLS WITHOUT THE PRESENCE OF INSULIN

FEEDBACK LOOPS

INCR IN LEVELS OF FATTY ACIDS & KETONES

ISLET -CELLS

GLUCAGON

ANABOLIC ENZYMES INHIBITED SECRETION OF

INSULIN

GLYCOGEN BREAKDOWN

LIPID & PROTEIN CONVERSION TO GLUCOSE

INCR. AMINO ACIDS

DECR. GLUCOSE

PARASYMPATHETIC ACTIVITY

INSULIN

DIABETESDifferent types of diabetes

Type I (juvenile diabetes, insulin dependent)Genetic predispositionOnset in childhood or early teens

Type II (adult-onset, non-insulin dependent)Obesity – mostly adults 40+Excess sugar in blood stream

Gestational

Frequent urination

Excessive thirst

Extreme hunger or constant eating

Unexplained weight loss

Presence of glucose in the urine

DIAGNOSISThe amount of glucose (sugar) in your blood is measured in mmol/L.

Fasting blood glucose (FPG)You must not eat or drink anything except water for at least eight hours before this test. A test result of 7.0 mmol/L or greater indicates diabetes.

Casual blood glucoseThis test may be done at any time, regardless of when you last ate. A test result of 11.0 mmol/L or greater, plus symptoms of diabetes, indicates diabetes.

Oral glucose tolerance testYou will be given a special sweetened drink prior to this blood test. A test result of 11.1 mmol/L or greater taken two hours after having the sweet drink indicates diabetes.A second test must be done in all cases (except if you have acute signs and symptoms).

TREATMENTS

Insulin injections

Monitoring of blood glucose

Planning of meals (foods & times)

Weight loss

World prevalence of diabetes (per million

persons)

Cost of Diabetes(billions of dollars)