Chapter Ⅶ. The Endocrine Pancreas
PS Wang/ 2004.05
1
Islets of Langerhans
(ovoid, 1-2% of the wt. of pancreas)
1. A cell (20%)
2.
3.
4.
5.
glucagon
catabolic,
mobilizing glu., FFA & A.A.
from stores into blood stream
B cell (>50%) insulin
anabolic, increasing
the storage of glu.
D cell (1-8%) somatostatin
insulin,
glucagon
No designation (few)
pancreatic polypeptide
function unknown
the fifth cell type
2
PS Wang/ 2004.05
3
Yen & Jaffe 23-1 #240
4
Hadley Endocrinology 1988 2nd ed #2007
5
Ganong Review of Medical Physiology 2003 21st ed #256
6
Ganong Review of Medical Physiology 1985 12th ed #258
7
Ganong, W.F. Review of Medical Physiology 23rd Edition, ©2010 by The Mc Graw-Hill Companies, Inc.
Akt = protein kinase B
GLUT-4 =Glucose transporter type 4
IRS-1 = insulin receptor substrate-1
8
Modified from http://student.biology.arizona.edu/honors2003/group05/bg.html
9
Ganong Review of Medical Physiology 1985 12th ed #1428
10
Hadley Endocrinology 1988 2nd ed #2008
11
Hadley Endocrinology 1988 2nd ed #2009
12
Ganong Review of Medical Physiology 2003 21st ed #259
13
Ganong Review of Medical Physiology 2003 21st ed #156
14
Ganong Review of Medical Physiology 2003 21st ed #1429
15
Ganong Review of Medical Physiology 2003 21st ed #260
16
#206
17
Hadley Endocrinology 1988 2nd ed #2013
18
#165
Characteristics of Diabetes Mellites
polyuria, polydipsia (= excessive thirst),
weight loss in spite of polyphagia ( appetite)
hyperglycemia, glycosuria, ketosis, acidosis,
coma
19
PS Wang/ 2004.05
Glucose Tolerance
If a glucose load is given to a diabetic,
the blood glucose rises higher and
returns to the baseline more slowly
than it normally does
20
PS Wang/ 2004.05
Glucagon
Chemistry ----1. polypeptide, 29 A.A.
2. MW = 3485
3. t1/2 = 5-10 min
4. synthesized from proglucagon
5. degraded by liver
Effects ------ 1. glycogenolytic, gluconeogenic, lipolytic
2. stimulates adenylate cyclase (in liver)
glycogen break down
blood glucose
3. does not cause glycogenolysis in muscle
4. stiumlates the secretion of GH, insluin, SRIF
Regulation of secretion ---- 1. protein meal
2. starvation
glucagon
glucagon
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PS Wang/ 2004.05
22
#163
Hadley Endocrinology 1988 2nd ed #2010
23
Ganong Review of Medical Physiology 2003 21st ed #158
24
Ganong Review of Medical Physiology 2003 21st ed #157
25
Hadley Endocrinology 1988 2nd ed #2012
26
27
Ganong Review of Medical Physiology 1999 19th ed #160
Human Diabetes
Juvenile Diabetes :
onset in childhood or adolescene
frequently ketoacidosis
B cell disorders
pancreatic insulin content is low
Maturity Diabetes :
onset in adult (obese people)
ketoacidosis is rare
B cell morphology is normal
pancreatic insulin content is normal
PS Wang/ 2004.05
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29
Tepperman & Tepperman Metabolic and Endocrine Physiology 1997 5th ed #1239