Separate negative feedback effects of estrogen on the pituitary and the central nervous system in the ovariectomized rhesus monkey

Endocrinology
R F WeickD L Thompson

Abstract

The site(s) of the negative feedback action of estrogen on gonadotropin secretion were studied in the ovariectomized rhesus monkey by observing the serum LH and FSH responses to intravenous GnRH injections at various times after implantation of Silastic capsules filled with estrogen. Circulating estrogen concentrations produced by the capsules were within the normal midcycle range for this species. Four h after estrogen implantation, no LH or FSH response was seen to the GnRH injection, indicating a suppressive effect of the steroid directly on the pituitary. Twelve and 22 h after estrogen implantation, however, the LH and FSH responses were equal to or larger than control responses. Since preinjection LH and FSH levels were below control values at these times and the pituitary responded to exogenous GnRH, it appears that endogenous GnRH secretion was affected, indicating an inhibitory action of estrogen on the central nervous system. Thus these experiments suggest 2 separate negative feedback actions of estrogen: a transient one directly on the pituitary and a longer lasting effect on the central nervous system.

Related Concepts

Trending Feeds

COVID-19

Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Blastomycosis

Blastomycosis fungal infections spread through inhaling Blastomyces dermatitidis spores. Discover the latest research on blastomycosis fungal infections here.

Nuclear Pore Complex in ALS/FTD

Alterations in nucleocytoplasmic transport, controlled by the nuclear pore complex, may be involved in the pathomechanism underlying multiple neurodegenerative diseases including Amyotrophic Lateral Sclerosis and Frontotemporal Dementia. Here is the latest research on the nuclear pore complex in ALS and FTD.

Applications of Molecular Barcoding

The concept of molecular barcoding is that each original DNA or RNA molecule is attached to a unique sequence barcode. Sequence reads having different barcodes represent different original molecules, while sequence reads having the same barcode are results of PCR duplication from one original molecule. Discover the latest research on molecular barcoding here.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Evolution of Pluripotency

Pluripotency refers to the ability of a cell to develop into three primary germ cell layers of the embryo. This feed focuses on the mechanisms that underlie the evolution of pluripotency. Here is the latest research.

Position Effect Variegation

Position Effect Variagation occurs when a gene is inactivated due to its positioning near heterochromatic regions within a chromosome. Discover the latest research on Position Effect Variagation here.

STING Receptor Agonists

Stimulator of IFN genes (STING) are a group of transmembrane proteins that are involved in the induction of type I interferon that is important in the innate immune response. The stimulation of STING has been an active area of research in the treatment of cancer and infectious diseases. Here is the latest research on STING receptor agonists.

Microbicide

Microbicides are products that can be applied to vaginal or rectal mucosal surfaces with the goal of preventing, or at least significantly reducing, the transmission of sexually transmitted infections. Here is the latest research on microbicides.