LSC 432 Basic Pharmacology April 1, 2003 Diabetes: Basics & Drugs Kenneth L. Campbell Professor of Biology Univers

1. LSC 432 Basic Pharmacology April 1, 2003 Diabetes: Basics & Drugs Kenneth L. Campbell Professor of Biology University of Massachusetts at Boston

2. This presentation is made possible by a grant entitled“Shortcourses in Endocrinology at Minority Undergraduate Institutions”from the National Institute of General Medical Sciences (NIGMS) to The Minority Affairs Committee of the Endocrine Society

3. The Medical Problems of Diabetes & Obesity Over 16 million in the US have clinically diagnosed diabetes mellitus; about 8% of the population. Of these, 91% have type 2 diabetes (strongly linked to obesity) & 9% have type 1 diabetes (autoimmune & genetic origin). Up to 16% of US whites have diabetes by age 70. Prevalences are often higher in other ethnic groups. > 65% of the US population is > 20% over the healthy body weight for their height, age, & gender & at risk for diabetes, cardiovascular disease (heart attack, stroke), & high blood pressure

4. Acute Problems in Diabetes Hyperglycemia: leads to hyperosmolality of serum, polyuria, dehydration, Na+ & K+ imbalances, weakness/fatigue, polyphagia with weight loss, glycosylation of proteins Ketoacidosis: decreases blood pH, HCO3-2, Hb avidity for O2; leads to hypoxic coma &/or tachycardia Hypoglycemia (especially in treated diabetics): lack of brain glucose leads to neuropathy & coma, autonomic hyperactivity

5. www.michiganeye.com/images / retinopathy/pic2.gif www.telemedicine.org/ dm/dg.jpg www.mds.qmw.ac.uk/biomed/kb/metabolism/Pancreas%20lecture/sld019.htm www.telemedicine.org / dm/dd.jpg

6. www.mds.qmw.ac.uk/biomed/kb/metabolism/Pancreas%20lecture/sld020.htmwww.mds.qmw.ac.uk/biomed/kb/metabolism/Pancreas%20lecture/sld020.htm

7. Glucose Homeostasis The body must control glucose levels because all cells use glucose to make ATP, the energy currency of cells. Some tissues like brain almost never burn any other fuel molecule. But too much glucose damages cells by getting attached to certain proteins and changing their function. Key tissues in this balancing act are: Liver Fat Muscle Brain Pancreas (endocrine cells)

8. The Liver is Central to Processing of Sugars. Converts many simple sugars, several amino acids, acetate & glycerol to glucose ( =gluconeogenesis) then secretes it into blood. Stores glucose as a macromolecule, glycogen, & hydrolyzes glycogen to glucose. Makes fat from fatty acids & glycerol, & breaks fat down to acetate & glycerol. Stores amino acids as protein, & can break proteins down to amino acids.

9. After meals glucose from liver is mainly stored as glycogen in liver & muscle & as fat in fat cells. When more energy is needed between meals, glycogen, fat & protein (last) are broken down & liver uses the parts to make glucose. Hormones (insulin, glucagon, adrenalin, cortisol) signal the change from storage to synthesis.

13. Islets of Langerhans http://medlib.med.utah.edu/WebPath/jpeg4/ENDO039.jpg Pancreas Glucagon Insulin Hormones Control the Glucose Balance Insulinacts on body cells to allow them to take in circulating glucose. Insulin levels rise when glucose rises. Adrenaline, cortisol, & growth hormone also make blood glucose rise. But insulin-like-growth factor I acts like insulin. Glucagonacts on liver to stimulate glucose production & release, & on fat to cause fat breakdown.Glucagon rises when glucose falls.

14. www.labvision.com/images / IHCimage/1422.jpg αlpha cell www.biols.susx.ac.uk/home / Julian_Thorpe/tem20.jpg .../ Julian_Thorpe/tem26r.jpg ß cell Blood flow is away from ß cells toward the outer cells. Insulin may block glucagon release. αlpha cells, red, lie at the outer edges of islets along with D & F cells.

16. www.umanitoba.ca/dnalab/ graduate/pancreas13.gif

17. Mechanism of Action of Insulin www.umanitoba.ca/dnalab/ graduate/pancreas19.gif

18. www.mds.qmw.ac.uk/biomed/kb/metabolism/Pancreas%20lecture/sld014.htmwww.mds.qmw.ac.uk/biomed/kb/metabolism/Pancreas%20lecture/sld014.htm

19. Diagnosis & Monitoring of Diabetes Thirst, polyuria, unexplained weight loss Hyperglycemia, random test > 200 mg/dL Elevated fasting glucose > 126 mg/dL Elevated glucose tolerance curve Glycosuria Ketonuria Tests for capillary blood glucose Tests for ketonuria Tests for glycosylated hemoglobin, HbA1c

20. www.mds.qmw.ac.uk/biomed/kb/metabolism/Pancreas%20lecture/sld016.htmwww.mds.qmw.ac.uk/biomed/kb/metabolism/Pancreas%20lecture/sld016.htm

21. www.umanitoba.ca/dnalab/graduate/pancreas28.gif

22. Traditional Treatments in the Southwest Diabetesis ahot illness (characterized by vasodilation & a high metabolic rate). Various remedies are used: nopal (or cactus), aloe vera juice, bitter gourd. In some areas in Texas & Mexico treatment is started with maturique root infusion for about 1 week if the person is extremely hyper-glycemic. Then, for maintenance therapy, trumpet flower-herb or root infusion (tronadora), brickle bush (prodigiosa) tea, or sage tea (salvia) are used. Proven safety & efficacy of maturique, trumpet flower, or bricklebush are not known. Aloe vera juice is reasonably safe but aloe vera latex is a powerful purgative. Sage tea taken chronically can lower the seizure threshold & has been reported to cause mental & physical deterioration because it contains thujones & tannins. [Nancy Neff, Dept. of Community Medicine, Baylor College of Medicine Module VII, Folk Medicine in Hispanics in the Southwestern United States, ww.rice.edu/projects/HispanicHealth/Courses/ mod7/mod7.html]

23. Drugs for Diabetes Type 1 chemcases.com/olestra/ images/insulin.jpg Multiple preparations available Differ in multimerization of insulin, up to hexamers, & resulting speed of absorption, action, & clearance Ultra-short acting, 5-15’ = lispro Short acting, 15-30’ = regular Intermediate acting, 2-4 h = NPH, Lente Long acting, 4-5 h = Ultralente Insulin Idea in Rx is to provide basal insulin + peaks after meals

24. How fast is the insulin response to glucose?

25. Antidiabetic (Hypoglycemic) Drugs • Intestinal brush border α glucosidase inhibitors • Stimulants of insulin release: sulfonylureas, meglitinide analogs • Blockers of gluoneogenesis: Biguanides • Insulin mimics or PPARγ activators: thiazolidinediones • Possibilities • Endogenous insulin secretagogues: glucagon-like peptide 1 • Glucagon antagonists

26. Sulfonylureas Stimulate insulin release from ß cells via binding to the SU receptor = K+ATP channel Mostly long metabolic T1/2 After www.bentham.org/sample-issues/cmc9-1/kecskemeti/fig-1.gif

27. Sulfonylurea Actions on ß Cells After www.bentham.org/sample-issues/cmc9-1/kecskemeti/fig3.gif

28. Meglitinide Analogs Bind to ß cells via SU receptor Rapid absorption, metabolism & clearance, T1/2 < 1 h After www.bentham.org/sample-issues/cmc9-1/kecskemeti/fig8.gif

29. Biguanides Act by inhibiting liver gluconeogenesis & increasing insulin sensitivity in other tissues Metformin is not metabolized, but excreted intact in 2-5 h After www.bentham.org/sample-issues/cmc9-1/kecskemeti/fig9.gif

30. Thiazolindinediones Partial mimics of isulin actions, may bind insulin receptor or act through the peroxisomal proliferator activated receptor γ Metabolized with a long half life After www.bentham.org/sample-issues /cmc9-1/kecskemeti/fig10.gif

31. Counterindications for Drug Use Compromised liver function Renal impairment Cardiovascular problems Advanced age Concurrent use of contraceptive steroids or other medications

32. After www.diabetes-mellitus.org/slidesho/slide22.gif

33. Troglitazone Metabolites Kecskemeti1*, V., Z. Bagi1, P. Pacher1, I. Posa2, E. Kocsis2 & M. Zs. Koltai2 (~2000) New Trends in the Development of Oral Antidiabetic Drugs, www.bentham.org/sample-issues /cmc9-1/kecskemeti/Kecskemeti-ms.htm

34. www.diabetes-mellitus.org/slidesho/slide5.gif

35. Prospects for Long-Term Curespumpsimplantsgene therapies

36. Body Mass Homeostasis: Our New Understanding www.garvan.org.au/library / images/jpg/adipocytes.jpg

37. A Little About the Central Players

38. Summary: Diabetes is a group of pathologies. Type 1 is due to autoimmunity to pancreatic ß cells & demonstrates genetic predispositions. Type 2 seems due to chronic overwork of ß cells & often appears during old age, especially in the chronically overweight. Monitoring tools are available as are drugs and therapies. ß cell implants are being tested. Prevention of Type 2 is often accessible by control of life-style. Prevention of Type 1 will only be possible when causes are identified.

41. www.umanitoba.ca/dnalab/graduate/pancreas30.gif

42. www.umanitoba.ca/dnalab/graduate/pancreas30.gif

43. Fats are often broken down after being absorbed by the small intestine. They are moved as complexes wrapped in specific proteins. The earliest complexes have the most fat relative to protein and are the least dense. hsc.usf.edu/2005/ lipoprotmet.jpg

44. users.cybercity.dk/.../diabetes/ billeder/glut2.JPG

45. Modified from www.pharmacology2000.com/Endocrine/ Diabetes/Alpha.gif

46. Definition of Diabetes

47. What kinds of hormone are there? chemcases.com/olestra/ images/insulin.jpg chem.pdx.edu/~wamserc/ ChemWorkshops/ gifs/W25_1.gif website.lineone.net/~dave.cushman/ epinephrine.gif • Known Hormonal Classes • Proteins & peptides • Lipids (steroids, eicosanoids) • Amino acid derived (thyronines, neurotransmitters) • Gases (NO, CO)