Endocrine- Pancreas Pathology
Card Set Information
Endocrine- Pancreas Pathology
vetmed pancreas pathology endocrinology
Glucagon _________ insulin; insulin ________ glucagon.
Glucagon _________ somatostatin; somatostatin _________ glucagon.
Juvenile onset of hypofunction of pancreatic islets is __________, characterized by... (2)
type I diabetes mellitus; lack of beta cells and insulin
Type I DM is ________, making patients prone to _________.
Type I DM is initiated by a ___________ combined with _______ to... (3)
genetic predisposition; viral exposure; coxsackievirus, mumps, rubella (induces immune reaction against islets)
Type I DM is seen in ________ (vetmed); it initially steams from __________ destruction of islets.
keeshond pups; immune-mediated lymphocytic inflammatory
Inherited DM in Keeshonds exhibits __________ inheritance; clinical signs include... (5)
autosomal recessive; stunted growth, hyperglycemia, hypercholesterolemia, hypoinsulinemia, normal blood glucagon
Why does Type I DM lead to stunted growth in keeshond pups?
hypoinsulinemia causes decreased protein anabolism and decreased AA uptake by muscle cells
Type II DM is ________; insulin conc is ________ and blood glucose is _________.
insulin-independent; normal to increased; increased
Describe the condition of pre-diabetes.
increased insulin, normal blood glucose; beta cells are hyperfunctioning trying to overcome insulin resistance
Type II DM is characterized by _________.
______ (species) are very prone to type II DM.
Horses often have pre-diabetes/metabolic syndrome associated with ________.
What is the primary mechanism of insulin resistance with type II DM? What are its repercussions in the patient? (3)
down-regulation of insulin receptors; obesity, cortisol/GH excess, damage to pancreas
When is accelerated insulin degradation a major source of insulin resistance?
What is unique about rat islets?
rat islets can proliferate beta cells, leading to higher production of insulin--> makes rats less susceptible to Type II DM
What is the current theory on betatropin gene function?
stimulates insulin secretion and beta cell hyperplasia in rats
What is the progression to type II DM?
insulin resistance--> beta cells make more insulin to overcome--> stress on beta cells--> death/atrophy of beta cells
How has the degeneration of islets been described in diabetic cats?
early on, islets swell; then, islets become vacuolated, vacuoles contain glycogen; finally, glycogen degeneration of the islets
What processes play a role in islets atrophy in type II DM? (3)
degeneration of islet cells, inflammation, macrophages
In cats, ________ may predispose them to type II DM.
Amyloidosis is a(n) _________ lesion in cats.
What is the most common islet lesion in cats with clinical diabetes?
Amylin lowers _________ and increases _________.
glycogen synthesis; hepatic glucose output
Type III DM involves _________ of islets due to... (5)
destruction; [chronic] chronic pancreatitis or cancer of exocrine pancreas, [acute] pancreatitis with hemorrhage and necrosis
Chronic relapsing pancreatitis ultimately leads to... (4)
necrosis, fibrosis, atrophy, type III DM
What are secondary lesions associated with DM? (5)
weight loss, cystitis, skin infections, liver cirrhosis, cataracts
Describe cataracts associated with DM. (3)
bilateral opacity of lens, asteroidal, diffuse
Diabetic hepatomegaly occurs because lack of insulin leads to __(2)__; also, there is toxic injury due to ___________.
lipolysis, increased mobilization of fat; hyperketonemia
What are the 2 components of cirrhosis of the liver due to DM?
fibrosis and regenerative hyperplasia
Cirrhosis of the liver is a sequelae to __________.
chronic fatty liver necrosis
Pancreatic endocrine tumors are usually _________, ie. _________.
beta cell adenoma; functional insulinoma
Insulinoma may result in the following functional disturbances... (2)
convulsive seizures due to hypoglycemia (exercise or fasting), favorable response to exogenous glucose
Pancreatic endocrine tumors occur most commonly in... (3)
dogs, ferrets, cattle
Pancreatic endocrine tumors are usually _________ carcinomas with a __________ that may take years to develop.
well-differentiated; high incidence of metastasis
Clinical signs of insulinoma in ferrets. (6)
weight loss, pytalism, muscle tremors, hind limb weakness, hypoglycemia, hyperinsulinemia
In ferrets insulinoma has a ______ of metastasis and a high incidence of...
low; recurrence in the pancreas after excision.
Insulinoma in cattle is often found at slaughter as distant metastases in the _______ and ________.
regional lymph nodes; liver
You see white nodules in the pancreas of an aged cat upon necropsy/exploratory surgery. What's going on?
exocrine nodular hyperplasia- common aging change, ESP in cats- NOT NEOPLASIA
DM is a relative or absolute _____________, resulting in... (3)
insulin deficiency; chronic hyperglycemia, abnormal fat/protein metabolism, and damage to various organs.
DM etiology has a spectrum from __________ to __________.
pure insulin resistance; complete lack of insulin production
In order to diagnose DM, hyperglycemia must be documented __________ and best must be done to rule out _________ in cats.
consistently; stress hyperglycemia
What are the consequences of hyperglycemia? (4)
glucose toxicity, cataracts, peripheral neuropathy, PU/PD
PU/PD with DM is caused by ___________.
Inability of peripheral tissues to use glucose leads to reliance on ________ and _________ as energy sources.
Insulin deficiency leads to ________ in adipose tissue, _______ of fat, and _________. This leads to an immediate increase in serum __(2)__ and _________.
lipolysis; breakdown; weight loss; FFA and cholesterol; fatty liver
Insulin deficiency leads to decreased ____________, leading to muscle breakdown and __________.
protein anabolism; weight loss
How does insulin deficiency lead to polyphagia?
satiety center in the brain has insulin dependent mediated uptake of glucose
A decrease in the insulin:glucagon ratio in the liver leads to increased __________.
Clinical signs/hallmarks of insulin deficiency. (4)
polyuria, polydipsia, polyphagia, weight loss
Diabetic _____ WILL develop cataracts; diabetic ______ usually do not.
75% of diabetic dogs will develop cataracts within _______ of diagnosis.
Glucose enters the lens freely; in a normal individual, it's used for energy; in a diabetic, the ________ is saturated, and glucose is metabolized through the _________ to __(2)__.
glycolytic pathway; polyol pathway; fructose and sorbitol
__(2)__ are not freely permeable in the lens and lead to _________ of lens fibers and _______.
Fructose and sorbitol; swelling/rupture; cataracts
Diabetic peripheral neuropathy is common in ________; it often presents as _________ with ___________.
diabetic cats; plantigrade posture; hocks touching the ground
Etiologies of DM. (4)
inherited beta cell aplasia, beta cell destruction (drugs, viruses, pancreatitis, autoimmune), beta cell dysfunction, insulin resistance
Type I DM results from _________ and loss of_________; there is often a _________; breed predisposition is ___________; ___________ breed are at low risk.
autoimmune destruction; beta cells; genetic predisposition; terriers/small dogs; large breed/boxers
Diabetic dogs are usually classified as __________ because most dogs are _______ at diagnosis.
Type I DM; insulin-dependent DM
In dogs, there is frequently an associated with DM and __________, which is _________.
pancreatitis; Type III DM
Type II DM is characterized by __________ and __________.
beta cell dysfunction; insulin resistance
Type II DM has a strong association with ________.
Risk factors for type II DM include __(2)__.
decreased physical activity, genetics
Onset of Type II DM is usually ________ in life.
mid to late
Amyloid deposition occurs in ________ and affects beta cells by ________.
cats and people; damaging them
The proinsulin:insulin ratio is _________ in Type II DM and is an early marker of _________.
increased; beta cell dysfunction
Decreased proinsulin conversion to insulin may predispose to ____________.
In type II DM, insulin secretion is always at least ________ and in late disease is _________.
relatively decreased (relative to hyperglycemia); absolutely decreased
A key feature of type II DM, there is decreased sensitivity of _______ to _______ and defects in the _________, leading to decreased __(2)__.
beta cells; glucose; incretin effect; GIP and GLP-1
Glucose toxicity results from ___________; it causes... (4)
chronic persistent hyperglycemia; impaired insulin secretion, down-reguation of glucose transport, beta cell injury/death, overt diabetes
What populations of cats are at greater risk for type II DM? (6)
male, neutered, obesity, old age, decreased physical activity, glucocorticoid and progestin administration
Most cats are first presented as ________.
Insulin deficiency is present but it is typically not an _________, rather ___________.
absolute deficiency; relative to the degree of insulin resistance
In healthy individuals, insulin resistance results in...
compensatory response and increased capacity to secrete insulin.
In diabetic individuals, insulin resistance leads to...
an abnormality in beta cells that does not allow an appropriate compensatory response.
Insulin resistance occurs when a given concentration of insulin produces...
less biologic response than normal.
Physiologic causes of insulin resistance. (5)
circulating insulin antagonists (counterregulatory hormones, cytokines), target tissue defects (receptor defects)
Lifestyle causes of insulin resistance. (3)
obesity, inflammation, stress
Results of insulin resistance in the liver. (1)
increased glucose output
Results of insulin resistance in muscles/fat. (1)
decreases glucose uptake
Results of insulin resistance in the pancreas. (4)
increased beta cell mass, increased insulin resistance, increased stress on beta cells, damage/death of beta cells
If the pancreatic response to insulin resistance is normal, it results in _______ and ________ [insulin].
If the pancreatic response to insulin resistance is abnormal, it results in _________ and ________ [insulin].
hyperglycemia; slightly increased-low
More obscure causes of DM. (4)
endocrinopathy, drugs, gestation, pancreatitis