Endocrine Flashcards
What are the two types of cell surface receptors?
tyrosine kinase
G-protein coupled
Which hormones are hydrophilic and which are lipid soluable?
hydrophilic- insulin, catecholamines, pituitary hormones
lipid- thyroid, steroid
what hormones bind to tyrosine kinase cell receptors?
insulin, insulin-like growth factor-1, epidermal growth factor, fibroblast and platelet-derived growth factor)
What glucose test results suggest diabetes?
A random or two hour glucose test > 11mmol/L
A fasting glucose >7 mmol/L
What to do if uncertainty around T1 or T2 diabetes?
formal oral glucose tolerance test with measurement ofinsulin and c eptide. High concentrations of insulin and c-peptide on baseline and two hour blood samples would indicate the presence of T2D.
What antibody titres are raised in T1DM?
glutemate decarboxylase
What is T1 DM? and when do symptoms emerge?
T cell-mediated autoimmune damage to pancreatic β-cells
After destruction of > 90% of β-cells
What HLA types are associated with T1dM?
DQA, DQB and DRB
When can’t you used hbA1c monitoring for diabetes? what use instead?
haemaglobinopathies
continuous glucose monitoring or fructosamine
How does metformin work?
suppresses hepatic gluconeogenesis.
How do sulfonylureas work?
bind to the potassium channel on the pancreatic β-cell, precipitating membrane depolarization, calcium influx and insulin release
What are patients with T2DM linked with developing
polycystic ovaries
What is MODY?
maturity-onset diabetes of the young
ususally mild mutation in transcription facors in beta cells of pancreas casuing varying insulin release but it still works
characterise MODY
mild asymptomatic hyperglycaemia in non-obese children, often with a strong autosomal dominant family history of ‘diabetes’ associated with low or non-existent risks of complications
hypoglycaemia + hepatosplenomegaly suggests what?
Glycogen storage disorder
hypoglycaemia + tall stature and excess weight suggests what?
hyperinsulinism
hypoglycaemia + optic atrophy suggests what?
septo-optic dysplasia
hypoglycaemia + Cranial midline defects, short stature, microgenitalia suggest what?
Pituitary disorder
hypoglycaemia + Increased skin/ buccal pigmentation and hypotension
Addison’s disease
hypoglycaemia + Abnormal ear-lobe creases, macroglossia, umbilical hernia, hemihypertrophy suggests what?
Beckwith-Wiedemann syndrome
What are genes commonly implicated in congenital hyperisnulinism?
sulphonylurea receptor (ABCC8) and associated potassium inward rectifying channel (KCNJ11).
What is the treatment for congeital hyperinsulinism?
chlorothiazide and diazoxide-induces hyperpolarization, decreased calcium influx and reduced insulin secretion.
somatostatin analogue may be used to exert a direct receptor-mediated inhibition of insulin release.
What types of cells produce calcitonin?
parafollicular cells in the thyroid
Where is most T3 produced?
converted from T4 by Type II deiodinase in peripheral tissues
