After reading this article you will learn about the meaning and purpose of hormonal therapy.
Meaning of Hormone Therapy:
Research attempts of recent past has added a lot to understand the functioning of the body endocrine orchestra, yet the knowledge has certain limitations which makes hormonal therapy difficult and deficient. However, it is worth knowing why endocrine pharmacology differ from classical pharmacology.
The reasons behind such difference can be summarized as below:
Limitations of the Receptors:
Receptors are located in/on the cells of the effector organs and work as sensors for specific stimuli. But sometimes even the specific receptors fail to sense the appropriate stimuli and accept other stimuli structurally similar to its specific one.
For example hydrocortisone (Cortisol) a glucocorticoid not immediate essential for life may occupy the receptors for aldosterone because both are structurally very similar (Fig. 22.8). Hence glucocorticoids may exhibit some Na+ retaining and K+ eliminating effect on renal tubules.
Insulin in higher doses behaves like somatotrophic hormone and exhibits growth promoting effects. It is so because the former occupies the somatomedin receptors.
Purpose of Hormone Therapy:
While prescribing hormone(s) its purpose should be properly decided whether it is meant for replacement therapy or additive therapy. Replacement therapy constitutes administration of the hormone in physiologic level to bring about usual physiologic effects as if the concerned endocrine gland is functioning normally. Treatment with Insulin, Thyroxin, Gonadotrophins and ACTH fall under this category.
Additive therapy either by natural or synthetic hormone(s) aim at utilizing the side effect of the concerned hormone, and for such purposes they are administered in higher doses. For example administration of progestin in higher doses interfere with the functioning of pituitary gonadal axis leading to anestrus and infertility. This adverse effect of progestin has been utilised as contraceptive in bitches.