Steroid hormones are believed to enter cells solely by free diffusion through the plasma membrane. However, recent studies suggest the existence of cellular uptake pathways for carrier-bound steroids. Similar to the clearance of cholesterol via lipoproteins, these pathways involve the recognition of carrier proteins by endocytic receptors on the surface of target cells, followed by internalizat...

Corticotropin-releasing hormone (CRH), a 41 amino acid polypeptide, is expressed in many regions of central nervous system and peripheral tissues and mediates many physiological functions. Abnormal production of CRH is involved in some pathological processes. Among various endogenous factors that modulate CRH production, steroid hormones control CRH production by regulating its gene transcripti...

Steroid sex hormones have a significant effect on different organ systems. As far as gingiva are concerned, they can influence the cellular proliferation, differentiation and growth of keratinocytes and fibroblasts. Estrogen is mainly responsible for alterations in blood vessels and progesterone stimulates the production of inflammatory mediators. In addition, some micro-organisms found in the ...

This study investigates the effect of steroid and polypeptide hormones on human NK cell activity in vitro. Solutions of hormones were incubated with normal peripheral blood cells in a 4 h cytotoxic assay against the NK-sensitive erythromyeloid cell line K562. The steroid hormones oestradiol, progesterone and testosterone did not exhibit a significant effect on K562 lysis at concentrations withi...

Oestrogenic steroid hormones (‘oestrogens’) have a crucial role in cellular regulation in all vertebrate species. The levels required to bring about such changes are very low, around 0.1–1 pg/ml (picograms per millilitre) of serum. It has been known for over five decades that oestrogens affect the development of the male reproductive system of mammals (Zuckerman, 1940). Nonetheless, oestrogenic...