Hydrocortisone

Cortisol (Hydrocortisone)- C21H30O5 - is a steroid hormone that is produced by the zona fasciculata and is released when people are stressed or have low levels of blood sugar. Its primary function is to increase blood sugar, suppress the immune system and aid in fat. Hydrocortisone is a white crystalline powder.


 * Uses:**
 * commonly found in topical treatments, hydrocortisone cream, is an anti-itch, anti-inflammatory and anti-pruritic agent cream to be applied to rashes, eczema, insect bites, poison ivy, poison oak etc. But also available in oral treatments.
 * A preparation of this hormone obtained from natural sources or produced synthetically and used to treat inflammatory conditions and adrenal failure.

Effects

Cortisol is released in response to stress, acting to restore homeostasis.

Main functions in the body
It downregulates the [|Interleukin-2 receptor] (IL-2R) on [|"Helper" (CD4+) T-cells]. This results in the inability of Interleukin-2 to upregulate the [|Th2] (Humoral) immune response and results in a [|Th1] (Cellular) immune dominance. This results in a decrease in [|B-cell] [|antibody] production. Cortisol prevents the release of substances in the body that cause inflammation. This is why cortisol is used to treat conditions resulting from over activity of the B-cell mediated antibody response such as inflammatory and [|rheumatoid] diseases, and [|allergies]. Low-potency hydrocortisone, available over the counter in some countries, is used to treat skin problems such as [|rashes], [|eczema] and others. It stimulates gluconeogenesis (the breakdown of protein and fat to provide metabolites that can be converted to glucose in the liver) and it activates anti-stress and anti-inflammatory pathways. Another function is to decrease bone formation. Low levels of cortisol in the body are associated with [|Addison’s disease].
 * increasing blood sugar through [|glycogenolysis] and reduction of glucose uptake into cells.
 * suppressing the immune system
 * aiding in fat, protein, and carbohydrate metabolism

Clinical chemistry

 * **Hypercortisolism**: Excessive levels of cortisol in the blood. (See [|Cushing's syndrome] .)
 * **Hypocortisolism** ( [|adrenal insufficiency] ): Insufficient levels of cortisol in the blood.

Biosynthesis
   [|Steroidogenesis], showing cortisol at right. Cortisol is synthesized from [|cholesterol]. Synthesis takes place in the // [|zona fasciculata] // of the [|adrenal cortex]. (The name //cortisol// is derived from //cortex//.) While the adrenal cortex also produces [|aldosterone] (in the //zona glomerulosa//) and some [|sex hormones] (in the //zona reticularis//), cortisol is its main secretion. The medulla of the adrenal gland lies under the cortex, mainly secreting the catecholamines adrenaline (epinephrine) and noradrenaline (norepinephrine) under sympathetic stimulation. The synthesis of cortisol in the adrenal gland is stimulated by the [|anterior lobe] of the [|pituitary gland] with [|adrenocorticotropic hormone] (ACTH); ACTH production is in turn stimulated by [|corticotropin-releasing hormone] (CRH), which is released by the [|hypothalamus]. ACTH increases the concentration of cholesterol in the inner mitochondrial membrane, via regulation of the STAR (steroidogenic acute regulatory) protein. It also stimulates the main rate-limiting step in cortisol synthesis, in which cholesterol is converted to pregnenolone and catalyzed by Cytochrome P450SCC ( [|side chain cleavage enzyme] ).