Final answer:
The mechanism of action of estrogen involves its binding to specific estrogen receptors within a target cell, followed by transcriptional activation, which leads to various cellular responses including cell proliferation and tissue growth. This action can also influence feedback mechanisms like the production of luteinizing hormone.
Step-by-step explanation:
Mechanism of Action of Estrogen
The mechanism of action of estrogen involves several key steps that enable this hormone to exert its effects on target cells. Estrogen belongs to the class of steroid hormones, which are capable of crossing the plasma membrane due to their lipophilic nature. Once inside the target cell, estrogen binds to specific estrogen receptors. This hormone-receptor complex then translocates to the cell nucleus where it can bind to DNA regulatory elements, acting as a transcription factor to either enhance or silence gene transcription. Consequently, this interaction leads to the synthesis of mRNA and subsequent protein synthesis, which may include enzymes or structural proteins resulting in cell growth, tissue growth, and alteration in the physiological functions of the cells.
Further effects of estrogen can include the upregulation of enzyme synthesis, alteration in cell membrane permeability, changes in the rates of mitosis and cell growth, and the stimulation of secretion of other hormones or cellular products. For instance, estrogen can enact a positive feedback loop by stimulating the production of luteinizing hormone (LH), which is crucial during the female reproductive cycle.
Therefore, the correct depiction of the mechanism of action of estrogen is: A. Binding to estrogen receptors, transcriptional activation, cell proliferation, tissue growth, feedback inhibition. Estrogen can also have other effects such as mitogenic actions and alterations in gene expression through activation or deactivation of transcription factors.