Endocrine and Metabolic Diseases Flashcards
In cats an elevated alkaline phosphatase is an indicator of active liver disease. Why are mild elevations in this enzyme are considered more significant in cats compared to dogs?
Cats normally have lower ALP activity than dogs
The half-life of ALP in cats is much shorter compared to dogs (6hrs compared to 72 hours)
Cats do not have the steroid isoenzyme induced found in the liver
Proteinuria is routinely detected by semiquantitative methods. What advantage does the sulfosalicylicturbidimetric test have over the dipstick colorimetric test?
Increased sensitivity
Ability to detect proteins other than albumin
What is the most common cause of pseudohypoglycemia in laboratory specimens?
In vitro glycolysis occurs if plasma or serum
is not separated from the red blood cells
Polymyopathy with profound cervical ventroflexion is associated with what electrolyte imbalance in cats?
Hypokalemia
List a breed of dog in which benign familial hyperphosphatasaemia with markedly increased alkaline phosphatase has been reported
Siberian Husky
Scottish Terrier
Most peptide hormones initiate their actions by activating what pathway?
cell membrane enzyme adenylcyyclase and the cyclic adenosine mono-phosphate system (cAMP).
What is the treatment of choice for cats with Cushings?
adrenalectomy
GH has opposing effects. Its catabolic activity is mediated by GH, whereas the anabolic activity is controlled by what hormone?
somatomedins (IGF)
**Growth hormone is important for development of T cell function and development of thymus.
Excessive GH causes what disease?
Acromegaly
What two breeds are is pituitary dwarfism thought to be an inherited autosomal recessive condition?
GSD and Carnelian bear dog
Most affect dogs have a variably sized Rathke cleft cyst in the pituitary gland resulting in varying degrees of anterior pituitary insufficiency.
Immunodeficient dwarfism occurs in what breed?
Weimeraners
**These dogs have deficient lymphocyte blastogenic responses to phytomitogens, as well as thymic cortical hypoplasia.
What other lab results would support diagnosis of pituitary dwarfism?
Radiography may reveal delayed closure of growth plates of long bones, delayed eruption of permanent teeth, failure of the os penis to mineralize completely by 2 year of age and open fontanelle of the skull, smaller than normal heart, liver and kidney.
What is a characteristic metabolic abnormality of GH-deficient dogs?
hypersensitivity to the hypoglycemic effect of insulin - severe prolonged hypoglycemia.
Progestin administration in normal dogs increase what two hormones?
GH and IGF
Cats and dogs both have insulin-resistant diabetes
Most cases of acromegaly are in intact ____
females - progestin induces production of GH
These dogs usually respond well to OVH
What test response is considered a hallmark of acromegaly?
Nonsuppressibility of plasma GH levels after an IV glucose loading dose is considered a hallmark of this disease (1 g/kg).
Estrogens are produced by what three organs?
ovarian follicles
zona reticularis
Sertoli and interstitial cells of testicles
FSH stimulates ovarian follicular growth and estrogen production in females. What does it stimulate in males?
spermatogenesis
What change in the skin of dogs is a feature of clinical dermatoses associated with hyperestrogenism of dogs?
cutaneous hyperpigmentation…..and alopecia
What organs produce androgens?
interstitial cells of testicle
zona reticularis
conversion of other sex hormones
What hormone causes androgen secretion by testicular interstitial cells?
LH
Regarding hyperestrogenism, what is typically the underlying cause? What breed is predisposed?
Cystic ovaries and rarely with a functional tumor.
**English bulldogs
What has been reported in toy poodles with pseudohermophrodites?
cystic ovaries and hyperestrogenism
Most estrogen-producing ovarian tumors are what type?
granulosa-theca cell tumors
Hereditary syndrome of male pseudohermaphroditism, cryptorchidism, Sertoli cell neoplasia and feminization as been reported in what breed?
Miniature schnauzers
What clinical feature is highly suggestive of feminization in male dogs?
Linear prepututial dermatosis = testicular neoplasia
Circumanal gland and tail gland hyperplasia is associated with what tumor in male dogs?
Interstitial cell tumors
What biochemical abnormality is most likely the cause of SND?
hypoaminoacidemia
**Can be due to glucagonoma
Xanthomatosis has been reported in cats with presumed hereditary _______.
hyperlipoproteinemia
Minoxidil is a ______ that has been used to topically or orally treat people with patterned baldness.
vasodilator
Parafollicular cells within the thyroid gland lie within the interstitial between follicles and secrete what hormone?
calcitonin
Synthesis of thyroglobulin is regulated by what hormone?
TSH
TSH production in the pituitary is primarily regulated by ___ produced within the pituitary gland from deiodination of circulating T4, with modulation by TRH from hypothalamus.
T3
Feline paraneoplastic alopecia is associated with what tumor?
pancreatic adenocarcinoma
Nodular dermatofibrosis is associated with what two tumors has been descried in German Shepherds. What is the gene associated with this disease?
renal cystadeocarcinomas or cystadeomas
FLCN (chromosome 5) = folliculin
What breed is predisposed to Leishmaniasis in North America?
Foxhounds
What drug is used as maintenance for Leishmaniasis and has been proven to maintain dogs in a maintenance state and decreases vector borne transmission?
Allopurinol
What is a dopamine D2 receptor antagonist with an immunomodulatory effect prescribe to prevent and control leishmaniasis in dogs?
Domperione
Samples from what area are best for testing PCR on suspected Leishmaniasis case?
LN
Xanthomas are associated with what hereditary defect in cats?
hypercholesterolemia
What dog breed is at increased risk for developing SLE?
GSD
TSH stimulates the synthesis and release of what hormones.
T3 and T4
T4 must undergo what process to become T3 and then be able to bind to receptors
Deiodination
40-60% of T3 is derived from T4 in peripheral tissue.
TSH secretion decreases what hormones?
somatostatin, dopamine, catecholamine TNF and some interleukins.
What breed of dog has a naturally lower level of T4?
sight hounds
What is the biologically active form of thyroxine?
fT4
It regulates pituitary function of TSH
Equilibrium dialysis fT4 levels are most accurate (sensitive and specific)
An elevate ___ serum level and a decreased ___ concentration are consistent with hypothyroidism diagnosis with an accuracy of 86%.
TSH
fT4 by equilibrium dialysis
What is the effect of sulfas and hypothyroidism?
Sulfas decrease T4 secretion from the thyroid glands and cause functional hypothyroidism and increased TSH.
8 week wash out according to May.
The hypothalamus is stimulated to secrete CRH by what inflammatory cytokines? hormones?
IL-1,IL-6 and TNF
Leptin, Dopamin, Angiotensin II and ADH
POMC is cleaved into what two biologically active fragments?
MSH and ACTH
The zona glomerulosa lacks what enzyme and is therefore unable to produce cortisol or or androgens?
17-alpha-hydroxylase
What enzyme does Trilostane inhibit?
This is a synthetic steroid analogue that competitively inhibits 3-b-hydroxysteroid dehydrogenase which is the same needed to convert pr4enenolone and 17-a-hydoxypregnalone to progesterone and 17-a-hydroxyprogesterone (precursors of cortisone synthesis)
What MOI inhibitor and D2 dopaminergic receptor agonist is most effective in dogs with pars intermedia tumors?
Selegiline hydrochloride (MOI inhibitor) Cabergoline (D2 agonist)
