Endo Lec 6 Flashcards
alpha cell in pancreas produces
glucagon
beta cell in pancreas produces
insulin;amylin
delta cell in pancreas produces
somatostatin
F/PP cell in pancreas produces
pancreatic polypeptide (PP)
D1 cell in pancreas produces
vasoactive intestinal polypeptide (VIP)
5 hormones of the pancreas
- glucagon
- insulin;amylin
- somatostatin
- pancreatic polypeptide (PP)
- vasoactive intestinal polypeptide (VIP)
% alpha cells of islet cells
15-20%
% beta cells of islet cells
55-90%
% delta cells of islet cells
3-10%
% F/PP cells of islet cells
1%
% D1 cells of islet cells
<1%
insulin : hormone of __
feasting
glucagon: hormone of __
fasting
insulin is an___ hormone
anabolic
glucagon is a ____ hormone
catabolic
insulin increases
uptake and storage of fuels
glucagon increases
mobilization of fuels when needed
catabolic hormones (4)- liberation of stored body fuels
- glucagon
- epinephrine
- cortisol
- growth hormone
insulin is the only hormone that can …
promote the storage of each of the major body fuels (glucose, fats, aa)
targets for insulin action (3)
- skeletal/cardiac muscle
- adipocytes
- hepatocytes
insulin action in liver
↑ glycogenesis, glycolysis,fat synthesis, protein synthesis
↓ glycogenolysis, gluconeogenesis, fat breakdown, ketogenesis, protein breakdown
insulin action in muscle
↑ glucose uptake, glycogenesis, a.a uptake, protein synthesis
↓ glycogenolysis, protein breakdown
insulin in adipose tissue
↑ glucose uptake, glycolysis, fatty acid uptake, fat synthesis
↓ fat breakdown
transporter protein that insulin-sensitive
GLUT-4
transport of glucose by secondary active transport (uphill, Na+ dependent)
SGLT 1 SGLT 2 (up to SGLT 6)
transport of glucose by facilitated transport (downhill, Na+ independent)
GLUT 1 GLUT 2 (up to GLUT 14)
insulin effect for GLUT 4
insulin increases GLUT 4 insertion in membrane
glycogen stores from liver is broken down by ___ (12-24 hours)
glycogenolysis
gluconeogenesis
new glucose is made from non-carbohydrate sources like aa/fatty acids
in liver acetyl-coA used
for fatty acid synthesis
Insulin deficiency (relative or absolute) is associated with a
catabolic state where Glucagon is predominant and energy substrates are liberated into the blood
Glucose uptake into fat and muscle is impaired as
90% of GLUT-4 transporters are sequestered intracellularly in vesicles in this setting
glucagon is the dominant hormone during
fasting
causes of hypersecretion of insulin
Insulin secreting tumor,overdose
consequences of hypersecretion of insulin
- hypoglycemia
- increased sympathetic activity (such as palpitations or sweating)
- increased production of counter regulatory hormones (such as glucagon, adrenaline)
- person feels tired, becomes confused and drowsy
- In severe cases, a person can have convulsions and go into
coma
causes of hyposecretion of insulin
-too little insulin (hyperglycemia) -increased blood glucose
consequences of hyposecretion of insulin
- diabetes mellitus
- ketoacidosis (ketones produced in excess)
Type 1 diabetes mellitus (summary)
– It is an autoimmune disease – Often seen in young people – b cells are destroyed – Absolute insulin deficiency – ~5-10% of all DM cases in North America
Type 2 diabetes mellitus (summary)
– Increased resistance to insulin
– Strongly associated with obesity
– Traditionally more common in adults, observed lately in obese young children
– Relative insulin deficiency
– ~90-95% of all DM cases in North America
Insulin deficiency leads to a catabolic state characterized
-by hyperglycemia, generalized wasting, acidosis and ketogenesis = DIABETIC KETOACIDOSIS
Cardinal Symptoms of Diabetes Mellitus
- Polyuria (↑ in urine volume, ↑ in frequency of urination)
- Glucosuria (glucose in urine)
- Polyphagia (increased hunger)
- Polydipsia (increased thirst)
Chronic Complications of Diabetes Mellitus
- Long-term high levels of glucose leads to blindness
- renal failure
- atherosclerosis
- changes in sensation
- poor wound healing
treatments of diabetes mellitus (type 1)
-insulin: by injection, by programmable pump, by inhalation, along with amylin analogs
– Islet cell transplant (Edmonton Protocol)
– Gene therapy
treatments of diabetes mellitus (type 2)
–dietary control and exercise
– Drugs which increase insulin secretion and/ or response to insulin
– Insulin administration
