Steroids are hormones

Steroid hormone

English: steroid hormones

1 definition

Steroid hormones are hormones that are made up of a cholesterol-derived steroid skeleton, which consists of three C6 rings and a C5 ring as well as a side chain.

2 properties

Steroid hormones belong to the group of lipid hormones. As lipophilic substances, they can easily permeate through cell membranes and thus occupy the intracellular steroid receptors. G-protein-coupled receptors on the cell membrane are also known for some steroid hormones.[1]

In humans, steroid hormones are mostly produced in the adrenal cortex, in the gonads and in the CNS. Since they are poorly soluble in water, they are transported in the blood bound to plasma proteins.

3 synthesis

The starting product of all steroid hormones is cholesterol. It can come from different sources:

The first, rate-limiting step in steroid synthesis is the conversion of cholesterol to pregnenolone. Pregnenolone is a weak progestogen and has a progesterone-like effect.

The various steroid hormones are then produced from the pregnenolone in several intermediate steps. The synthesis of steroid hormones takes place in the ovaries (ovaries), in the testes (testes) and in the adrenal gland. Hormone production is controlled by hypothalamic and pituitary hormones.

4 examples

Examples of steroid hormones are:

Steroid-like hormones are:

Hormones from insects and plants are also often built on a steroid base.

5 sources

  1. ↑ Prossnitz et al. Estrogen signaling through the transmembrane G protein-coupled receptor GPR30. Annu Rev Physiol; 2008