Page 85 - Physiology and Pathophysiology MNU 2024-2025 نظرى

Clinical pharmacy 2024/2025 Level 2 Pharm D Physiology and Pathophysiology (MD303)

2- Prolactin (PRL)

 Involved with the initiation and maintenance of lactation in females.
 Its function in males is uncertain.
Lactation involves three processes:

Mammogenesis Lactogenesis Galactopoeisis
Growth & development of The initiation of lactation. maintenance of milk
mammary glands that a. During pregnancy  lactation is production.

produce the milk. inhibited by high levels of  requires PRL &
 Requires the actions estrogens & progestins. oxytocin.

estrogens & progestins, At delivery  the levels of these two
in addition to PRL. hormones fall  PRL initiate
lactation.

The release of prolactin from the adenohypophysis is:

inhibited by Stimulated by

prolactin-inhibiting hormone prolactin-releasing factor (PRF) from hypothalamus
(PIH, dopamine) from the  Mediated by reflexes elicited by suckling and
hypothalamus breast stimulation.

3- Adrenocorticotropic hormone (ACTH, adrenocorticotropin)
a. Stimulates growth & steroid production in the adrenal cortex.

b. Stimulates secretion of cortisol & other glucocorticoids involved with carbohydrate
metabolism.

The release of ACTH from the adenohypophysis is influenced by more than one factor.

1. Corticotropin-releasing hormone (CRH) from the hypothalamus  stimulates
the secretion of ACTH.

2. ACTH secretion follows a diurnal pattern  peak in the early morning & valley
in the late afternoon.

4- Gonadotropins

FSH: Follicle-stimulating hormone & LH: Luteinizing hormone

 Exert their effects on the gonads (ovaries in the female and testes in the male).
 Stimulate the gonads to:

a. Produce gametes (ova and sperm)
b. Secrete sex hormones (estrogen, progesterone, and testosterone)

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