Hypothalamus and Pituitary Gland Hormones

Sample

1. The most commonly used sample is serum.
2. In some cases, 24 hours urine sample is collected.

Indications

1. These hormones are estimated for:
   1. Diagnostic purposes.
   2. For a therapeutic reason.
   3. To evaluate ovulation.
   4. To evaluate spermatogenesis.
   5. To treat endometriosis and uterine fibroids.
   6. To evaluate precocious puberty.
   7. To treat prostatic carcinoma.
   8. To find GH deficiency.

Pathophysiology

1. The neurons that give rise to hypophysiotropic hormones are themselves influenced by the hypothalamic neurotransmitter like:
   1. Dopamine.
   2. Serotonin.
   3. Norepinephrine.
   4. Endorphin.
   5. Acetylcholine.
2. These neurotransmitters modify the secretory activity of the anterior pituitary gland.
3. Cytokines also modify this neuroendocrine axis.
   1.  The hypothalamic-pituitary-adrenal axis is modified by the interleukin 1 (IL-1), and interleukin 6 (IL-6) which are produced as a result of infection or stress.

Hypothalamus Hormones:

1.  Corticotropin-Releasing Hormone (CRH).
   1. This hormone will stimulate the production and secretion of ACTH by the anterior pituitary glands.
2.  Thyrotropin Releasing Hormone (TRH).
   1. This hormone stimulates the production and secretion of TSH and prolactin by the anterior pituitary glands.
3. Gonadotropin-Releasing Hormone (GRH).
   1. This hormone stimulates the production and secretion of FSH and LH by the anterior pituitary gland.
4. Growth hormone-releasing hormone  (GRH).
   1. This hormone stimulates the production and secretion of GH by the anterior pituitary gland.
5. Growth hormone inhibiting hormone (GIH).
   1. This hormone inhibits the production and secretion of GH and TSH by the anterior pituitary gland.
6. Prolactin inhibiting factor (PIF).
   1. This is considered to be the neurotransmitter that inhibits the production and secretion of prolactin, TSH, FSH, LH, and GH by the anterior pituitary gland.
      

      Hypothalamus Hormones

Anterior Pituitary Gland:

1. Adrenocorticotropic hormone (ACTH).
   1. This hormone stimulates the secretion of cortisol by the adrenal gland.
2. Growth Hormone (GH).
   1. This hormone promotes growth in soft tissue, cartilage, and bone.
3. Thyroid stimulation hormone (TSH).
   1. This hormone stimulates the secretion of the thyroid hormone T3 and T4 by the thyroid gland.
4. Prolactin Hormone.
   1. This hormone main role is in the initiation and maintenance of lactation.
   2. Prolactin induces ductal growth and the development of the lobular alveolar system and synthesis of milk production.
5. Follicle-stimulating hormone (FSH).
   1. This hormone controls the functional activity of gonads.
   2. In the male, this stimulates spermatogenesis.
   3. In female stimulate the growth of ovarian follicles in the presence of LH. This promotes the secretion of estrogen by the mature follicle.
6. Luteinizing hormone (LH).
   1. This hormone controls the functional activity of the gonads.
   2. In male produces testosterone by the Leydig cells of testes.
   3. In female leads to release of the ovum from the ovarian follicle which is ripened by FSH.
   4. It transforms the follicle into a corpus luteum that secretes the progesterone.

Posterior Pituitary Gland:

1. Antidiuretic Hormone (ADH).

1. This maintains the water homeostasis.
2. It increases water reabsorption by the distal tubules and collecting ducts of kidneys which increases the concentration of urine.
3. This also leads to vasoconstriction to increase blood pressure.

2. Oxytocin.

1. This will stimulate uterine contraction during labor.
2. This may be used to induce labor.
3. It helps in the breast for milk release from the mammary ducts.
   

   Posterior pituitary glands hormones

 

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