Endocrine Flashcards
What is an adipokine? Name some examples?
Protein or hormone secreted from adipose cells
Ex: TNF alpha, leptin, adiponectin
How does leptin work?
Inhibits neurotransmitters that increase appetite and slow metabolism and stimulates neurons that decrease appetite and increase energy expenditure
Promotes weight loss
How does adiponectin work?
Most abundantly secreted adipokine in circulation
Lower levels w increased fat mass
Closely associated w insulin sensitivity
Low levels of adiponectin associated with chronic inflammatory states like obesity, insulin resistance, type 2 DM, cardiovascular disease
What is role of TNF-alpha in obesity?
This is a cytokines secreted by lots of cells including adipocytes
Obesity increases macrophage migration into adipose tissue, causing increased TNF alpha expression in overweight individuals
This causes local insulin resistance. It also decreases uptake of FFA into adipocytes and promoted lipolysis and release of FFA into circulation. FFA levels increase in circulation and negatively impact insulin sensitivity
MOA of slentrol (dirlotapide) and mitratapide (Yarvitan)?
Microsomal transport protein inhibition at intestines. Means that lipids don’t get assembled into apoprotein B, which means they don’t get absorbed
More importantly, the increased lipid causes secretion of satiety signals from gut (like pancreatic peptide Y, PYY) and inhibition of voluntary food intake
Examples of human weight loss drugs?
Sibutramine (Meridia)- inhibit serotonin and NE reuptake
Oralistat (Xenical)- increases fecal fat excretion
Phenteramine (Adipex-P)- increases metabolism similar to speed
What breeds are predisposed to hyperlipidemia?
HTG- schnauzer, beagle
HCH- Shelties, Dobies, Rotties, Briards, rough-coated collie, Pyrenees
What are some uncommon causes of hyperlipidemia?
Phenobarbital therapy, parvo, hypernatremia (maybe), Leishmania, lymphoma, hepatic insufficiency
How do omega 3 FA work to treat hyperlipidemia
Increased beta oxidation, reduced lipogenesis, and activation of LPL
MOA of niacin?
Not super known but inhibits hormone sensitive lipase and inhibits diacylglycerol acetyltransferase= reduced triglyceride synthesis
What side effects known for niacin in dogs? W
Myotoxicity maybe hepatotoxicty. Also erythema and pruritus
How does gemfibrozil work?
This is a fibric acid derivative. It inhibits peroxisome proliferator activated receptor alpha. This is a transcription factor that regulates lipid and lipoprotein synthesis and catabolism
Essentially it does a bunch of things that result in decreased triglyceride levels
Why no use statins in dogs?
Bc they’ll work on cholesterol not triglyceride
Also when used with fibrates there is an increased risk of hepatotoxicty
Which breed predisposed to primary hyperparathyroidism?
keeshonds
Do dogs with primary hyperthyroidism develop CKD bc of hypercalcemia?
NO! For some reason these dogs seem protected from renal failure
What are common co-morbidities of primary hyperparathyroidism?
UTI-30%
Cystic calculi- 30%
You have a patient w normal PTH and high calcium. What’s the diagnosis?
Primary hyperparathyroidism
As calcium levels rise PTH should become undetectable
When do you do pretreatment w calcitriol for PHP?
When total calcium greater than 15 or more than one parathyroid mass. They have a higher risk of post procedure hypocalcemia
What sort of tumor causes primary hyperparathyroidism?
Histologically classified as adenoma, hyperplasia, or carcinoma. Doesn’t matter bc they don’t met or invade and recurrence is 10% regardless of tumor type
What is desmopressin?
Synthetic analog of natural anti-diuretic hormone. Has increased ADH activity and prolonged duration of action, decreased pressor actions, fewer side effects than natural hormone.
What route of admin is best for desmopressin?
Maybe SC bc can give smaller amts more efficaciously and it lasts longer but you can do oral and conjunctival as well.
When do you consider doing a desmopressin response test?
When you’ve limited Ddx to central DI, nephrogenic DI or primary polydipsia
What results on desmopressin response test tell you it’s central DI?
> 50% reduction of water intake and polyuria strongly suggest diagnosis of central DI. But lack of any reduction in PU/PD is probably due to nephrogenic DI.
What are adverse effects of desmopressin?
Fluid retention, hyponatremia, decreased plasma osmolality. Water intoxication rarely can cause CNS disturbances. Give furosemide if it happens
Who gets diabetic nephropathy?
Cats more commonly than dogs. Usually proteinuria and hypertension are the manifestations and azotemia is a late consequence
Don’t see it that much in dogs bc they don’t live long enough
What is the mechanism of diabetic neuropathy?
Polyol pathway via aldose reductase promotes formation of sorbitol from glucose and then to fructose via sorbate dehydrogenase. Fructose accumulates in the nerves of cats and results in accumulation of glycation end products
Demyelination and splitting and ballooning of myelin are common in these cats
Why don’t cats get diabetic cataracts?
Less aldose reductase activity in the lens. Maybe that’s the cause
Which is the primary ketone in dogs and cats?
Beta hydroxybutryrate. Also, it’s not measured on urine dipstick!
Definition of obesity
Exceeding ideal body weight by 15-20%
What’s the pathogenesis of megaesophagus and decreased thyroid?
Unknown! May or may not recover fxn too
What’s mechanism of peripheral neuropathy w hypoT4?
Usually metabolic. Maybe consequence of impaired axial transport
If they have vestibular dz, it could be due to compression of facial and vestibular n as they cross internal acoustic meatus (unknown why)
