Endocrine Flashcards
how does hyperplasia of pars intermedia occur in PPID, and how does this lead to clinical signs?
neuron loss OR lack of dopamine
reduced inhibition of pars intermedia
melontrope cell proliferation = hypertrophy»_space;»> increased ACTH, etc
which hormones does the melanocytes of the pars intermedia produce
ACTH= Adrenocorticotropic hormone
CLIP = corticotrophin-like intermediate peptide
alpha MSH= α-melanocytestimulating hormone
what is the single cell type of the pars intermedia
melanocyte
2 aetiologies of PPID
neurogenerative lesion
pituitary tumour
what does PPID stand for
Pituitary Pars Intermedia Dysfunction
what does hypertrichosis mean?
delayed abnormal shedding > appears as thick curly coat
> 15 year old horse with
laminitis weight loss and weight redisribution wasted epaxial muscle and pot belly lethargy sweating PUPD thick curly coat
ddx?
PPID
2 tests for PPID
Basal ACTH
- blood test, EDTA tube
- chill asap and separate plasma
- affected by stress
TRH stimulation
- measure ACTH (PPID= increase/ exaggerated ACTH response to TRH)
- tests pituitary function specifically
can also do low dose dexmethasone suppression test and measure cortisol levels
why glucocorticoid levels not useful assessment of ACTH levels in PPID?
PPID most ACTH is metabolically inactive, so no real increase in cortisol etc
treatment for PPID
only 1
pergolide (dopamine replacement)
horse iwth inappentance after starting pergolide for PPID?
too high dose
when should you monitor ACTH levels during PPID treatment with Pergolide?
1 st at 4 weeks
3 monthly if stable for 9 months
maximum pergolide dose?
starting dose X5
starting dose of pergolide?
0.002mg/kg/day
pgx of PPID horse on pergolide?
> 7 years
horse <10 years, PPID
likeluy cause
pituitary tumour more likely than neurogenic degeneration (>15 years)
cause of goitre in a horse?
excess iodine in idet» secondary hypothyroidism»_space; goitre
EMS=?
equine metabolic syndrome
cause of EMS?
genetic predisposition + obesity + insulin resistance > hyperinsulinaemia
+ high concentrate diet
= laminitis
clinical signs of EMS
laminitis
frequent foot abscess white line disease lamellar rings seedy toe dropped sole
what does the obel grading system grade?
lamintis grade 1-4
diagnosis of EMS?
resting basal insulin, high insulin indicates yes
unfasted
hypertriglyceridaemia
elevated basal cortisol
high blood pressure
which endorinopathy?
EMS
why should you soak hay for 8-16 hours in EMS treatment?
reduce amount of NSC sugars
Excerise> diet> drugs for EMS treatment
which drugs can be used?
metformin (improve sensitivity to insulin to hope to decrease levels)
Exercise> diet> drugs for EMS treatment
how much decrease of BWT to help tx?
1.5-2% reducition
Exercise> diet> drugs for EMS treatment
why is exercise most important?
helps reduce obesity > insulin resistance
