Anterior Pituitary Hormones

What hormones are released by the anterior pituitary?

GH, TSH, ACTH, LH, FSH, Prolactin

What hormones are released by the hypothalamus?

GnRH, TRH, GHRH, CRH, Dopamine, Somatostatin

What 2 hormones are produced in the posterior pituitary?

ADH and Oxytocin

What 2 hormones activate the JAK/STAT pathway?

Prolactin, GH

Key functions of growth hormone

1. Carbohydrate and lipid metabolism 

2. Lean body mass and bone density

3. Growth during adolescence

Axis of GH?

Hypothalamus releases GHRH

Stimulates anterior pituitary to release GH

Stimulates Liver, Bones, or Muscles to release IGF-1

Growth hormone agonist

Somatostatin - Growth Hormone Agonist

Mecasermin - Recombinant IGF-1

Clinical use of growth hormone antagonist?

Acromegaly, when too much growth hormone is produced

Examples of growth hormone antagonists?

Pegvisomant - Growth Hormone receptor antagonist

Somatostatin analogues - Octreotide, Lanreotide

D2 Receptor agonists (due to negative feedback of dopamine on GH) - Bromocriptine

Somatostatin analogues

Octretide, Leuprolide

Examples of gonadotropins

FSH, LH, hCG

All gonadotropins exert their effects on what kind of receptors?

GPCR

What is the role of FSH in women?

Follicle support and development

What hormones play a role in steroidogenesis for women?

FSH and LH

What is the role of FSH in men

Regulation of spermatogenesis

What is the role of LH for men?

Regulation of androgen production

Name 3 therapeutic forms of FSH

Follitropin Alpha

Follitropin Beta

Urofollitropin

Complete the following chart:

FSH and LH are dimeric gonadotrophic hormones. FSH binds a _______ and induces transcriptional changes in the cell by activating ______.

A. Dimer of receptors, Calcium channels

B. G protein–coupled receptor, Calcium channel

C. G protein–coupled receptor, cyclic AMP

D. Dimer of receptors, JAK/STAT signaling

E. G protein–coupled receptor, JAK/STAT signaling

C. G protein-coupled receptor, cyclic AAMP

The only ones that are JAK/STAT are Prolactin and GH

Why does a continuous dose of GnRH agonist block steroid hormone expression in controlled ovarian hyperstimulation?

A. High blood GnRH agonist concentration blocks LH activity in the ovaries.

B. Continuous GnRH activation triggers GnRH receptors degradation

C. GnRH agonists inhibit gonadotropin activity.

D. Continuous GnRH agonist administration shrinks the ovaries.

Why does a continuous dose of GnRH agonist block steroid hormone expression in controlled ovarian hyperstimulation?

A. High blood GnRH agonist concentration blocks LH activity in the ovaries.

B. Continuous GnRH activation triggers GnRH receptors degradation

C. GnRH agonists inhibit gonadotropin activity.

D. Continuous GnRH agonist administration shrinks the ovaries.

Pulsatile GnRH increases fertility, as it can lead to hormone surges and increase in steroidogenesis. By providing a continuous dose of hormones, you downregulate the amount of receptors that are available to respond to FSH and LH

Which of the following drugs are alternative GnRH analogues?

1. Aberelix

2. Nafareline

3. Goserelin

4. Leuprolide

5. Degarelix

A. 1 & 5

B. 2 &4

C. 2 & 3

D. 2, 3, & 4

E. All of the above

* These are activators that drive down regulation 

Which of the following drugs are alternative GnRH analogues?

1. Aberelix

2. Nafareline

3. Goserelin

4. Leuprolide

5. Degarelix

A. 1 & 5

B. 2 &4

C. 2 & 3

D. 2, 3, & 4

E. All of the above

Relix = GnRH antagonists

* These are activators that drive down regulation 

Which graph would be seen in LH serum levels for a constitutional delay in LH?

1) Administration of GnRH would lead to an increase in LH levels if the parts are working

Which graph would be seen in LH serum levels for hypogonadotropic hypogonadism?

2) Administration of GnRH would have minimal effect of LH levels because the parts are not responding properly

Growth hormone antagonists can be used to treat acromegaly, by blocking the GH pathway. Which of the following is NOT a Growth hormone antagonists??

A. Bromocriptine

B. Lanreotide

C. Octreotide

D. Pegvisomant

E. Somatropin 

Growth hormone antagonists can be used to treat acromegaly, by blocking the GH pathway. Which of the following is NOT a Growth hormone antagonists??

A. Bromocriptine - D2 agonist

B. Lanreotide - Somatostatin agonist

C. Octreotide - Somatostatin agonist

D. Pegvisomant - Growth hormone antagonist

E. Somatropin - growth hormone analogue

Bromocriptine and Pegvisomant are all antagonists for which endocrine pathway?

A. They suppress ACTH release

B. They suppress growth hormone release

C. They suppress Follicle Stimulating hormone release

D. They suppress thyroid stimulating hormone release

Bromocriptine and Pegvisomant are all antagonists for which endocrine pathway?

A. They suppress ACTH release

B. They suppress growth hormone release

C. They suppress Follicle Stimulating hormone release

D. They suppress thyroid stimulating hormone release

Bromocriptine is a D2 agonist - dopamine can have inhibitory effects on GH

Pegvisomant is a GH receptor antagonist

Clinical uses for somatotropin

Somatotropin is a GH agonist

It can be used for disease related to GH deficiency

Genetic Disease associated with short stature

HIV Wasting

Use of mecasermin

treatment for children irresponsible to GH

Clinical use of growth hormone antagonists?

Acromegaly or GH secreting tumors; used for defective IGF-1 negative feedback loop

Therapeutic use of gonadotropins

Fertility, controlled ovarian hyperstimulation

Explain the gonadal axis

Hypothalamus releases GnRH

GnRH stimulates the release of LH and FSH

FSH is used for follicle development → produces estrogen to select the best follicle

LH surge is used for ovulation

Follicle expels the oocyte for implantation and awaits fertilization

Leftover sac is corpeus luteum, which releases progesterone and more estrogens to develop the lining

If no pregnant (hCG), drop in hormones initiates the restarting of the cycle

Examples of LH analogs

Lutropin alfa

Therapeutic use of LH

In combination with follitropin alfa for follicular development

Diagnostic use for distinguishing between retained testis (undescended) from retracted in prepubertal boys

use of hCG

Excreted in the urine and produced by the human placenta 

Choriogonadotropin alfa can be used in the final follicular development stage or development 

Pulsatile GnRH ____ and Sustained GnRH ____

Pulsatile GnRH stimulates gonadotropin release, and sustained GnRH inhibits FSH and LH release

GnRH analogues:

Gonadorelin, Leuprolide, Goserelin, histerelin, narfarelin, triptorelin

GnRH antagonists:

Ganirelix, Cetrorelix, and Degarelix inhibit FSH and LH secretion by binding to GnRH receptors 

Clinical use of GnRH and analogous:

Controlled ovarian hyperstimulation suppresses the LH surge and increases mature oocyte number

Ovarian suppression in endometriosis; helps reduce fibroid size to reduce progesterone and estrogen production

Prostate cancer in men

Central precocious puberty - GnRH agonists to suppress FSH to delay development of secondary sexual characteristics

How does fertility treatment work?

Via long GnRH agonist protocol, which seeks to use GnRH to suppress the LH surge alongside the use of FSH to help enhance follicle development to create a large amount of oocytes 

GnRH antagonist will help block the LH surge to help alongside FSH to enhance oocyte development

Fill in the respective drugs to the chart

Role of FSH and LH in the testes:

• LH stimulates androgen production

• FSH stimulates spermatogenesis