PT1

Name a hypo-secretion disorder?

Type I diabetes

Name a hyper-secretion disorder?

Pancreatic endocrine disorder

Name a hypo-responsive disorder?

Insulin resistant type II diabetes

Name a hyper-responsive disorder?

TSH receptor constitutive activator, hyperthyroidism

Describe the endocrine characteristics of the hypothalamus?

Modified neurosecretory cells, release hormones directly into local blood supply, to the A pituitary

Define primary hormones?

They work straight for the pituitary

Examples of primary hormones?

Growth hormone, prolactin, vasopressin, oxytocin

Where is Growth hormone, prolactin released from?

Anterior pituitary

Where is vasopressin, oxytocin released from?

Posterior pituitary

What are two consequences of hyposecretion of growth hormone?

Dwarfism, accelerated aging

Why may hyposecretion of GH cause dwarfism?

General A pituitary disfunction, specific GH deficit, normal GH but somatomedin deficit

Why may hyposecretion of GH cause accelerated aging?

Loss of GH after adolescence, decreased protein synthesis, decreased ability to renew and replace cell

What are two consequences of hypersecretion of growth hormone?

Giantism. Acromegaly

Why may hypersecretion of GH cause giantism?

Early life pituitary tumour

Why may hypersecretion of GH cause Acromegaly?

pituitary tumour after adolescence, slow onset

Treatment for Acromegaly?

Reduce GH production, surgery, drugs, radiations

What are the drugs for Acromegaly?

octreotide & lanreotide, pegvisomant, bromocriptine

Describe octreotide & lanreotide?

Somatostatin analogues, SRLs

Describe pegvisomant?

Growth hormone receptor antagonist

Describe bromocriptine

Dopamine agonist

Describe the characteristics of hyperprolactinaemia?

Benign pituitary tumour, negative feedback on GRH which stimulates LH, FSH

What is the common presentation of hyperprolactinaemia?

Galactorrhoea, Amenorrhoea, Hypogonadism, Erectile dysfunction, Vision loss

What is dopamine?

Prolactin inhibiting factor

Name the dopamine agonists?

Cabergoline, bromocriptine

Why is dopamine used in the treatment of hyperprolactinaemia?

Acts at D2 receptors in the pituitary gland to inhibit prolactin release

What are the problem with some antipsychotics in hyperprolactinaemia?

Some are D2 antagonists, can cause hyperprolactinaemia

What is hypopituitarism?

A deficiency in one or more pituitary hormones

What is Panhypopituitarism?

A deficiency in all anterior pituitary hormones

What are the cause of hypopituitarism?

Traumatic, infective, vascular, autoimmune, functional

What are the symptoms of hypopituitarism?

Mirror those of a primary deficiency in hormone secretion by the target endocrine gland

How is hypopituitarism managed?

Replacement therapy with the appropriate hormones

Where is TSH produced?

Pituitary gland

What are primary thyroid hormones?

Triiodothyronine T3, Thyroxine T4

What happens to T4 in the periphery?

Converted to T3 by deiodinases

How do thyroid hormones travel?

Bound to plasma proteins

Name plasma proteins that thyroid hormones are bound to?

thyroxine-binding globulin (TGB), transthyretin (TTR) and thyroxine binding prealbumin

What is the function of thyroid hormones?

Regulate BMR, enhance the actions of catecholamines

What are the two types pf hypothyroidism?

Primary and secondary

What is the most common form of hypothyroidism?

Atrophic hypothyroidism

How is atrophic hypothyroidism caused?

Antithyroid autoantibodies attack own thyroid

Describe Hashimotos thyroiditis?

More common in women associated with goitre

How is hypothyroidism diagnosed?

Increased level of serum TSH, low free T4 confirms and excludes TSH deficiency

What is the treatment for hypothyroidism?

Levothyroxine

How does the dosing for levothyroxine?

Dose depends on age, severity, fitness, 50-100 micrograms, typical maintenance 100 micrograms to 150 microgram

What is the most common form of hyperthyroidism?

Graves disease

How is graves disease caused?

Auto immune disease, stimulating TSH receptor antibodies, driving thyroid to make TH at the wrong time

Describe De Quervain’s thyroiditis?

Solitary toxic adenoma nodule and toxic multinodular goitre

What drugs can cause drug induced?

Amiodarone

How do you diagnose hyperthyroidism?

Decreased serum TSH, autoantibodies present, TPO and thyroglobulin present

What are the 3 treatment types of hyperthyroidism?

Antithyroid drugs, radioiodine, surgery

What are the main anti-thyroid drugs?

carbimazole (UK); thiamazole often co administered with a beta blocker