Morphine suppresses the proestrous surge of GnrH in pituitary portal plasma of rats

Endocrinology
M Ching

Abstract

Virgin proestrous rats were acutely treated with 2 doses of morphine sulfate (MS) (5-8 and 40 mg/kg BW) or naloxone HCl (NH) (10 mg/kg BW) co-administered with the high dose of MS, and the pituitary portal plasma concentrations of gonadotropin releasing hormone (GnRH) were compared with those of untreated proestrous (PE) and diestrous (DE) control animals. LH and FSH were measured in systemic plasma obtained by venipuncture just prior to the collection of portal blood. Both doses of MS severely diminished the PE surges of LH and FSH, but NH reversed the effect of MS and restored the circulating gonadotropins to PE levels. However, only PE rats treated with the high dose of MS exhibited significantly reduced GnRH concentrations in portal plasma. This suggests that the reduction of gonadotropin concentrations is not due merely to reduced GnRH secretion by the hypothalamus but may involve other mechanism(s) as well. However, in rats given the high dose of MS the severe reduction in pituitary gonadotropin secretion is attributable in large part to the corresponding decrease in hypothalamic GnRH release, since NH restored the GnRH and LH/FSH plasma concentrations to PE levels.

Citations

Jan 1, 1987·Journal of Steroid Biochemistry·P LimontaF Piva
Jan 1, 1988·Journal of Steroid Biochemistry·S P KalraW R Crowley
May 1, 1989·Physiology & Behavior·K T O'ByrneA F Dixson
Jan 1, 1991·Psychoneuroendocrinology·R M Sapolsky
Jan 1, 1991·Domestic Animal Endocrinology·C R BarbG B Rampacek
Dec 13, 2002·Fertility and Sterility·Raymond ChangZev Rosenwaks
Jan 1, 1997·Life Sciences·M M RoozendaalJ A Mattheij
Jul 21, 1998·Annals of the New York Academy of Sciences·A E CalogeroR D'Agata
Mar 8, 2007·Forschende Komplementärmedizin = Research in Complementary Medicine·Fan QuRui Nan
Jul 2, 2003·Journal of Neuroendocrinology·J C Wingfield, R M Sapolsky
Dec 20, 2007·Birth Defects Research. Part B, Developmental and Reproductive Toxicology·Dana L ShueyRonald J Gerson
Jul 7, 2000·Frontiers in Neuroendocrinology·J Bakker, M J Baum
Feb 1, 1989·The International Journal of Neuroscience·R Sandyk
Jun 14, 2018·Journal of Experimental Zoology. Part A, Ecological and Integrative Physiology·Alexander J HoffmanHaruka Wada

❮ 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.