SI Session Metabolism Spring 2010 For Dr. Wright’s Bio 6 Class Designed by Pyeongsug Kim ©2010

Review your understanding of catabolism and anabolism. Be able to discuss a mechanism by which each of the following affects blood glucose levels (i.e., does it increase or decrease blood sugar, and HOW): Insulin Glucagons Growth hormone/insulin-like growth factors Epinephrine Glucocorticoids Thyroxine Compare and contrast type I and type II diabetes mellitus with respect to: Age of onset Why blood glucose levels are high Is insulin deficient? Recommended treatment Are beta islet cells damaged? How does parathyroid hormone and/or vitamin D3 (1, 25-dihydroxyvitamin D3) affect: Reabsorption of calcium from intestine Reabsorption of calcium in kidneys Resorption of bone (Think: does it tend to put more calcium in the blood, or less?) What are the consequences of having low blood calcium? (review question!)

Designed by Pyeongsug Kim, ©2010Metabolism : All body’s process that transform energy.

Catabolism C  A + B + energy Breaking down into smaller molecules Chemical reactions in Metabolism: Anabolism A + B + energy  C Form larger molecules Reactants Product Reactant Products   + energy Designed by Pyeongsug Kim, ©2010

*Generally…. High levels due to CATABOLISM. Low levels due to ANABOLISM. Designed by Pyeongsug Kim, ©2010 Stimulates glycolysis (Catabolism).  increase blood glucose. Stimulate glycogenesis(Anabolism).  decrease blood glucose.

The hormones affect Blood glucose levels: Insulin Glucagons Growth hormone Insulin-like growth factors Epinephrine Glucocorticoids Picture from Designed by Pyeongsug Kim, ©2010

Insulin ↓ Blood glucose by stimulating… -Cellular uptake of glucose -Conversion of glucose to glycogen and fat. ↑ Blood glucose In Beta cell ↑insulin secretion In Alpha cell ↓Glucagon secretion Cells uptake glucose Liver/muscle: Glucose  Glycogen Adipose tissue: Glucose  Triglyceride ↓Blood glucose _____________: Glucose  Glycogen _____________: Glucose  Triglyceride Glycogenesis Lipogenesis Anabolism!! “-lysis”: Breakdown to smaller molecules “-genesis”: Making to a big molecules Designed by Pyeongsug Kim, ©2010 *Insulin is __________ of carbohydrate and lipids.anabolism (secreted by Pancreas (Beta cells)

Glucacon ↑ Blood glucose by stimulating… -Making glucose from glycogen and noncarbohydrates (triglyceride and amino acids) -Glycogenolysis(breakdown Glycogen into glucose) in the liver. -Glucogenesis ↑ Blood glucose In Beta cell ↓ insulin secretion In Alpha cell ↑ Glucagon secretion ↓ Cells uptake glucose Liver/muscle: Glucose ← Glycogen Adipose tissue: Glucose ← Triglyceride ↑ Blood glucose _____________: Glucose ← Glycogen _____________: Glucose ← Triglyceride(or noncarbohydrate) Glycogenolysis Gluconeogenesis “-lysis”: Breakdown to smaller molecules “-genesis”: Making to a big molecules Catabolism!! Designed by Pyeongsug Kim, ©2010 (secreted by Pancreas (Alpha cells)

Designed by Pyeongsug Kim, ©2010 From Dr. Wright’s Bio6 powerpoint

-Both sympathetic and parasympathetic nerves innervate pancreas -Sympathetic, along with epinephrine,  stimulates glucagon secretion  increase blood glucose -Parasympathetic  stimulates insulin secretion  ↑ gastrointestinal activity (digestion)  decrease blood glucose Designed by Pyeongsug Kim, ©2010 ANS system activity in metabolism

Designed by Pyeongsug Kim, ©2010 Growth hormone(GH) -Secreted by A.pituitary glands. -Controlled by GHRH (from hypothalamus) -stimulates growth in children and adolescents. -More secreted GH during stress and fasting in adults. -increased when fasting, stress, low blood glucose and high amino acid by skeletal muscle. Picture from

Designed by Pyeongsug Kim, ©2010 Insulin-like Growth factors (IGFs) -”Somatomedians” -Polypeptides(protein) produced by liver or many tissues. -mediators of some of GH actions. Cell division Cartilage and bone growth Protein synthesis in muslce & other organs. -Not mediated of GH actions. Lipolysis decreased glucose utilization.

Designed by Pyeongsug Kim, ©2010 Insulin-like Growth factors (IGFs)(Cont’d) From Dr. Wright’s Bio6 powerpoint

Designed by Pyeongsug Kim, ©2010 Growth hormone(GH) ↑ Blood glucose by stimulating… - ↓cellular glucose uptake; Glycogenolysis in the liver ↓ Blood glucose e.g. fasting In liver ↑Glycogenolysis ↓ Cells uptake glucose Muscle and other organ: Protein← amino acids Adipose tissue: fatty acids← Triglyceride ↑ Blood glucose ↑ amino acid in Blood ↓ amino acid in Blood ↑ fatty acids in Blood ↑GH in Anterior pituitary ↑GnRH in Hypothalamus (secreted by Anterior Pituitary glands)

Hormones for catabolism of carbohydrates and lipids Glucagon Growth hormone(GH) Epinephrine Glucocorticoids, Thyroxine Designed by Pyeongsug Kim, ©2010 *Insulin is __________ of carbohydrate and lipids.anabolism *However, GH and Thyroxine promotes protein synthesis  anabolism of protein.

Epinephrine Increase in stress. Produced in adrenal medulla ↑ Blood glucose by stimulating… -release glucose from liver (Glycogenesis) -Gluconeogenesis(making glucose from noncarbohydates)Glucocorticoids -Produced in adrenal cortex -Controlled by ACTH -Increased during prolonged fasting or exercise ↑Blood glucose by stimulating… - ↓cell glucose utilization -Gluconeogenesis(making glucose from noncarbohydates) ↑Lipolysis ↑protein breakdown in muscle. Designed by Pyeongsug Kim, ©2010

Thyroxine(T4) -Secreted in thyroxine by TSH. -response to low ATP -Increase cell respiration (to make more ATP) ↑ glucose utilization increase metabolic heat as a result of cell respiration.  Cold adaptation!! -participate in body growth and CNS in children. ↑ protein synthesis ↑ BMR(Basal metabolic rate) -Both hypothyroidism and hyperthyroidism  Cause muscle wasting(protein breakdown) -No direct in lipid metaolism. Designed by Pyeongsug Kim, ©2010 (secreted by thyroid follicles) A person with hypothyroidism cannot stand being cold. Picture from

Thyroxine(T4) (cont’d) Designed by Pyeongsug Kim, ©2010 -act on nearly every cell in the body. -participate in catabolism of carbohydrates and lipids -Tend to elevate blood glucose. -participate in protein synhesis. “T4 and T3 tend to ELEVATE PLASMA GLUCE and potentiate the effects of other HYPERGLYCEMIC hormones..ie.. NE, E, cortisol, glucagon, and GH”

Designed by Pyeongsug Kim, ©2010

DiabetesType 1Type 2 onset< 20 years> 40 years SymptomsRapidSlow Proportion10%90% Ketoacidosis?CommonRare Obesityrarecommon Beta cells damaged?YesNo Insulin secreted?DecreasedMay be increased Immunity to isletsYesNo MHC associationYes? Treatment?InsulinDiet, exercise, medication From Dr. Wright’s slide

Vitamin D3 (VD3) Vitamin D3 (VD3) (1, 25-dihydroxyvitamin D3) -Produce in the skin from sunlight  so, fall VD3 production during winter -PTH(parathyroid hormone) increase VD3 hormones -Increase Ca 2+ in blood by..... Reabsorption of calcium from intestine Reabsorption of calcium in kidneys Reabsorption CaPO4 crystals of bone In case of high calcium but normal phosphate VD3 – ↑reabsorption of phosphate and ↑reabsorption of calcium in the kidney. ↓ PTH - ↓ reabsorption of phosphate and ↑reabsorption of calcium in the kidney. See table 19.7 Endocrine regulation of Ca and phosphate balance Designed by Pyeongsug Kim, ©2010

_____ -increase resorption in bone. -increase absorption in small intestine. -increase absorption in kidney.  therefore, (lower/rise) Ca 2+ level in blood. ________ - inhibits dissolution of bone - stimulates excretion of Ca 2+ in urine  therefore, (lower/rise) Ca 2+ level in blood. Calcitonin PTH Calcium levels regulated by hormone- ______________ calcitonin & PTH Designed by Pyeongsug Kim, ©2010

When blood Ca2+ level rises…. Negative feedback! Designed by Pyeongsug Kim, ©2010

When blood Ca2+ level falls…. Negative feedback! Designed by Pyeongsug Kim, ©2010

Consequences of having low blood calcium -Result from inadequate amount of VD3 or low PTH  ↓Reabsorption Ca 2+ from bone, kidneys, and intestine  ↓ Blood Ca 2+  Bone demineralization to increase Blood Ca 2+ Osteomalacia, Osteoporosis rickets(in children) Bone demineralization – loss calcium from the bone Bone mineralization – deposit calcium into the bone Designed by Pyeongsug Kim, ©2010