The lateral and medial median eminence: distribution of dopamine, norepinephrine, and luteinizing hormone-releasing hormone and the effect of prolactin on catecholamine turnover

Endocrinology
M Selmanoff

Abstract

In the adult male rat, we have succeeded in microdissecting the median eminence into a LHRH-rich lateral region (MEl) and a LHRH-poor medial region (MEm). Dissected in this manner, the MEm has a 4.8-fold lower LHRH concentration and a 1.5-fold higher DA concentration than the MEl. The concentration of norepinephrine (NE) is not different in the two regions. Estimates of the rate constants for dopamine (DA) and NE decay after synthesis inhibition revealed no significant differences between the MEl and MEm kinetics for either amine. Hyperprolactinemia, produced by ovine PRL administration, resulted in marked increases in DA turnover rates in both the MEm (2.7-fold) and the MEl (4.7-fold). These effects of PRL were specific to the tuberoinfundibular DA neurons, as DA turnover was unaffected in nigrostriatal, mesolimbic, and incertohypothalamic DA neurons, and no changes were observed in NE turnover in any study area. The results support the involvement of PRL in the short loop feedback regulation of its own secretion in the MEm. The data further demonstrate a hypothalamic mechanism in the MEl by which hyperprolactinemia could inhibit LHRH release.

Citations

Jan 1, 1989·Progress in Neurobiology·N Ben-JonathanJ F Hyde
Jan 1, 1995·Brain Research Bulletin·D R Grattan, R L Averill
Dec 31, 2002·Archives of Medical Research·Murad AtmacaOmer Gecici
Apr 6, 1999·Schizophrenia Research·R G Petty
Oct 1, 1986·Journal of Neurosurgery·J I MechanickA LaRocque
Jul 1, 1982·Brain Research Bulletin·G E HoffmanM Goldstein
Aug 26, 2006·Peptides·Luciano Debeljuk, Mercedes Lasaga
Jun 20, 1984·The Journal of Comparative Neurology·R B Page, B J Dovey-Hartman
Jan 1, 1982·Progress in Neuro-psychopharmacology & Biological Psychiatry·K E Moore, K T Demarest
Mar 1, 1983·Clinics in Endocrinology and Metabolism·M J Cronin, W S Evans
Jan 1, 1986·Annals of the New York Academy of Sciences·C RobynS Meuris
Sep 1, 1993·Journal of Endocrinological Investigation·M E MolitchC P Barsano
Dec 1, 1982·The American Journal of Physiology·R B Page
Jan 1, 1983·The American Journal of Physiology·H K Mangat, S M McCann

❮ Previous
Next ❯

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.