Pathophysiology of the Endocrine Pancreas

Question 1

what do beta cells secrete?

Answer 1

insulin
amylin

Question 2

what percentage of the islet cells are beta cells?

Answer 2

60-70%

Question 3

what do delta cells secrete?

Answer 3

somatostatin

Question 4

what is the half-life of insulin?

Answer 4

3-5 minutes

Question 5

insulin is secreted at a constant basal level, and in a __________________ in response to increased blood glucose levels

Answer 5

bolus or spike

Question 6

what does insulin stimulate in hepatocytes?

Answer 6

glycogen storage

Question 7

is insulin required for glucose uptake in hepatocytes?

Answer 7

no: primarily use GLUT2 transporter

Question 8

where is somatostatin produced?

Answer 8

hypothalamus
stomach
intestine
pancreatic delta cells

Question 9

what does gastrin stimulate?

Answer 9

production of hydrochloric acid by parietal cells

Question 10

what is diabetes insipidus?

Answer 10

polyuria due to decreased ADH response or ADH deficiency

Question 11

what percentage of beta cells must be lost for clinical diabetes mellitus?

Answer 11

> 90%

Question 12

what does insulin resistance in the peripheral tissues cause?

Answer 12

decreased glucose uptake in response to insulin

Question 13

what happens with beta cells in type II/non-insulin dependent diabetes mellitus?

Answer 13

may be abnormal: beta cell exhaustion
may be overcome to some extent by increased secretion of insulin

Question 14

what are the clinical signs associated with diabetes mellitus?

Answer 14

polyuria/polydipsia
weight loss despite good appetite or polyphagia
hepatomegaly due to hepatic lipidosis
cataracts, more common in dogs than cats
dehydration
halitosis

Question 15

what are the consistent laboratory findings with diabetes mellitus?

Answer 15

hyperglycemia: marked and persistent
glucosuria

Question 16

what are some complications of diabetes mellitus?

Answer 16

ketoacidosis
cataract formation
hypokalemia/hyperkalemia
immune dysfunction
microvascular complications
urinary tract infections

Question 17

what type of acidosis do increased ketones cause?

Answer 17

titration-type
high anion gap

Question 18

______________ precedes ketonemia

Answer 18

ketonuria

Question 19

intracellular _____________ causes water influx by osmotic effect in diabetic cataracts

Answer 19

sorbitol

Question 20

chronic high levels of glucose lead to _________________________________________________

Answer 20

glycosylation of proteins in blood and tissues

Question 21

what type of diabetes mellitus do most dogs with diabetes mellitus have?

Answer 21

type I/insulin dependent

Question 22

what type of diabetes mellitus is usually the one in cats?

Answer 22

type II
~80%

Question 23

which cats have a higher incidence of diabetes mellitus?

Answer 23

neutered males
burmese, russian blue, abyssinian, norwegian forest

Question 24

what are some possible predisposing factors for feline diabetes mellitus?

Answer 24

glucose transport abnormalities
leptin resistance
reduced adiponectin
beta cell dysfunction
islet amyloidosis (not proven- only in humans)

Question 25

obese cats have reduced expression of _________ in muscle and adipose tissue

Answer 25

GLUT4

Question 26

what is leptin secreted by?

Answer 26

adipose tissue

Question 27

with positive energy balance, melanocortin 4 receptor (MC4R) is stimulated by alpha-melanocyte stimulating hormone (alpha-MSH), _______________________

Answer 27

increasing satiety

Question 28

what is acromegaly caused by?

Answer 28

hypersomatotropism excess growth hormone

Question 29

what does increased growth hormone case with insulin?

Answer 29

insulin resistance

Question 30

is diabetes mellitus common in ferrets?

Answer 30

no, uncommon

Question 31

what does cortisol cause in skeletal muscle?

Answer 31

insulin resistance

Question 32

what does cortisol cause in adipose tissue?

Answer 32

increased insulin sensitivity

Question 33

who is gestational diabetes described in?

Answer 33

dogs

Question 34

what causes gestational diabetes?

Answer 34

increased progesterone and growth hormone secreted in pregnancy or diestrus

Question 35

the amount of glycosylated protein can be measured to evaluate ___________________________

Answer 35

long-term blood glucose levels

Question 36

type II (insulin resistance) in horses may occur with ________________________________________

Answer 36

pituitary pars intermedia dysfunction (PPID)

Question 37

what do horses with equine metabolic syndrome have an increased tendency for?

Answer 37

obesity laminitis

Question 38

what happens in equine metabolic syndrome with adipose tissue?

Answer 38

obesity or accumulation of fat in focal areas

Question 39

true/false: glucose is usually within reference interval with equine metabolic syndrome

Answer 39

true

Question 40

in equine metabolic syndrome, what are the insulin and glucose levels?

Answer 40

high insulin normal or slightly elevated blood glucose

Question 41

equine metabolic syndrome horses exhibit an __________________ insulin response to carbohydrates

Answer 41

exaggerated

Question 42

avian diabetes mellitus may be secondary to increased _____________

Answer 42

glucagon

Question 43

do birds usually have higher baseline glucose than mammals?

Answer 43

yes

Question 44

what are some more common differentials for hypoglycemia?

Answer 44

excess insulin malabsorption artifactual/maldigestion

Question 45

what does the exocrine pancreas do?

Answer 45

produces digestive enzymes secrete into the intestinal lumen via pancreatic duct

Question 46

what do F (PP) cells secrete?

Answer 46

pancreatic polypeptide

Question 47

what do epsilon cells secrete?

Answer 47

ghrelin

Question 48

what degrades insulin?

Answer 48

insulinase insulysin liver and kidneys

Question 49

what is removed to make active insulin?

Answer 49

C peptide

Question 50

what might C peptide do?

Answer 50

activation of Na/K ATPase and nitric oxide synthase may be used to evaluate endogenous insulin secretion

Question 51

what does increased intracellular glucose concentration of glucose in the beta cells cause?

Answer 51

membrane depolarization and influx of extracellular calcium and exoxytosis of insulin containing granules diffuses in through GLUT2

Question 52

where does insulin bind to?

Answer 52

insulin receptor-kinases and insulin receptor substrate proteins

Question 53

where are Na/glucose cotransporters found?

Answer 53

enterocytes and renal tubules use Na gradient created by Na/K ATPase

Question 54

where are GLUT1 transporters found?

Answer 54

most cells red blood cells

Question 55

where are GLUT2 transporters found?

Answer 55

high expression liver, renal tubules, small intestine, beta cells

Question 56

where are GLUT3 transporters found?

Answer 56

neurons/brain

Question 57

where are GLUT4 transporters found?

Answer 57

striated and cardiac muscle and adipose tissue regulated by insulin

Question 58

what are the effects of amylin?

Answer 58

decrease glucagon secretion decreases gastric emptying increases satiety

Question 59

what does pancreatic polypeptide do?

Answer 59

inhibits gall bladder contraction and exocrine pancreatic enzyme secretion acts to antagonize cholecystokinin may act as satiety factor

Question 60

what does somatostatin act to inhibit the release of?

Answer 60

growth hormone thyroid-stimulating hormone insulin glucagon gastrin vasoactive intestinal peptide exocrine pancreatic enzymes prolactin

Question 61

gastrin is not normally secreted by the endocrine pancreas, but may be secreted by ____________________

Answer 61

islet neoplasia

Question 62

what are some diseases of the pancreatic islets?

Answer 62

metabolic disease neoplasia

Question 63

what might lesions in the pancreas manifest histologically as with type one diabetes mellitus?

Answer 63

inflammatory infiltrates in islets lack of visible islets islet cell degeneration/vacuolation

Question 64

what are some causes of diabetes-like syndrome (damage pancreas or induce insulin resistant due to another disease)?

Answer 64

diabetogenic hormones or drugs pancreatitis or pancreatic neoplasia

Question 65

what are some microvascular complications of diabetes mellitus?

Answer 65

diabetic retinopathy neuropathy nephropathy

Question 66

how are ketones formed?

Answer 66

fatty acids being broken down produce acetyl CoA insufficient Kreb's cycle intermediates so don't use up acetyl CoA forms ketones

Question 67

what can be measured to evaluate chronic hyperglycemia?

Answer 67

fructosamine glycosylated Hb measurement`

Question 68

what might glycosylation do?

Answer 68

interfere with antibody-antigen binding development of microvascular disease and neuropathy

Question 69

what dog breeds are more likely to get canine diabetes mellitus?

Answer 69

australian terrier miniature and standard schnauzer samoyed bichon frise fox terrier beagle miniature and toy poodles keeshond

Question 70

what do obese cats have reduced expression of?

Answer 70

GLUT4 in muscle and adipose tissue

Question 71

where is the melanocortin 4 receptor mainly expressed?

Answer 71

hypothalamus

Question 72

what does adiponectin do with insulin?

Answer 72

enhances sensitivity

Question 73

how can chronic high glucose levels reduce the number of beta cells?

Answer 73

overstimulation induction of apoptosis and inflammation amyloidosis may occur

Question 74

what are some other endocrinopathies that may present like diabetes mellitus in cats?

Answer 74

hypersomatrotropism/acromegaly hyperadrenocorticism

Question 75

what does hypersomatotropism/acromegaly cause with glucose?

Answer 75

glucosuria and hyperglycemia

Question 76

production of insulin-like growth factor-1 is increased by _____________________________

Answer 76

high growth hormone levels

Question 77

what are the effects of cortisol on glycemia?

Answer 77

insulin resistance in skeletal muscle tissue increased insulin sensitivity in adipose tissue liver: increases gluconeogenesis pancreas: stimulates glucagon release and inhibits insulin releease

Question 78

does a urine ketone dipstick detect beta-hydroxybutyrate?

Answer 78

no

Question 79

what happens in equine metabolic syndrome with insulin?

Answer 79

resistance/dysregulation

Question 80

where do horses accumulate fat with equine metabolic syndrome?

Answer 80

nuchal ligament behind shoulders tail base prepuce or mammary gland

Question 81

what are the clinical findings with equine metabolic syndrome?

Answer 81

hypertriglyceridemia increased insulin levels hyperleptinemia/leptin resistance

Question 82

what response to equine metabolic disease horses have to carbohydrates?

Answer 82

exaggerated

Question 83

what might avian diabetes mellitus be due to?

Answer 83

increased glucagon production type 1 with chronic pancreatitis

Question 84

what is the most common islet cell neoplasm in veterinary medicine?

Answer 84

insulinoma