Endocrine

Question 1

how does hyperplasia of pars intermedia occur in PPID, and how does this lead to clinical signs?

Answer 1

neuron loss OR lack of dopamine

reduced inhibition of pars intermedia

melontrope cell proliferation = hypertrophy&raquo_space;»> increased ACTH, etc

Question 2

which hormones does the melanocytes of the pars intermedia produce

Answer 2

ACTH= Adrenocorticotropic hormone
CLIP = corticotrophin-like intermediate peptide
alpha MSH= α-melanocytestimulating hormone

Question 3

what is the single cell type of the pars intermedia

Answer 3

melanocyte

Question 4

2 aetiologies of PPID

Answer 4

neurogenerative lesion

pituitary tumour

Question 5

what does PPID stand for

Answer 5

Pituitary Pars Intermedia Dysfunction

Question 6

what does hypertrichosis mean?

Answer 6

delayed abnormal shedding > appears as thick curly coat

Question 7

> 15 year old horse with

laminitis 
weight loss and weight redisribution
wasted epaxial muscle and pot belly 
lethargy
sweating 
PUPD
thick curly coat

ddx?

Answer 7

PPID

Question 8

2 tests for PPID

Answer 8

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

Question 9

why glucocorticoid levels not useful assessment of ACTH levels in PPID?

Answer 9

PPID most ACTH is metabolically inactive, so no real increase in cortisol etc

Question 10

treatment for PPID

Answer 10

only 1

pergolide (dopamine replacement)

Question 11

horse iwth inappentance after starting pergolide for PPID?

Answer 11

too high dose

Question 12

when should you monitor ACTH levels during PPID treatment with Pergolide?

Answer 12

1 st at 4 weeks

3 monthly if stable for 9 months

Question 13

maximum pergolide dose?

Answer 13

starting dose X5

Question 14

starting dose of pergolide?

Answer 14

0.002mg/kg/day

Question 15

pgx of PPID horse on pergolide?

Answer 15

> 7 years

Question 16

horse <10 years, PPID

likeluy cause

Answer 16

pituitary tumour more likely than neurogenic degeneration (>15 years)

Question 17

cause of goitre in a horse?

Answer 17

excess iodine in idet» secondary hypothyroidism&raquo_space; goitre

Question 18

EMS=?

Answer 18

equine metabolic syndrome

Question 19

cause of EMS?

Answer 19

genetic predisposition + obesity + insulin resistance > hyperinsulinaemia

+ high concentrate diet

= laminitis

Question 20

clinical signs of EMS

Answer 20

laminitis

frequent foot abscess
white line disease
lamellar rings
seedy toe
dropped sole

Question 21

what does the obel grading system grade?

Answer 21

lamintis grade 1-4

Question 22

diagnosis of EMS?

Answer 22

resting basal insulin, high insulin indicates yes

unfasted

Question 23

hypertriglyceridaemia
elevated basal cortisol
high blood pressure

which endorinopathy?

Answer 23

EMS

Question 24

why should you soak hay for 8-16 hours in EMS treatment?

Answer 24

reduce amount of NSC sugars

Question 25

Excerise> diet> drugs for EMS treatment

which drugs can be used?

Answer 25

metformin (improve sensitivity to insulin to hope to decrease levels)

Question 26

Exercise> diet> drugs for EMS treatment

how much decrease of BWT to help tx?

Answer 26

1.5-2% reducition

Question 27

Exercise> diet> drugs for EMS treatment

why is exercise most important?

Answer 27

helps reduce obesity > insulin resistance