Chronic liver failure induced by portocaval anastomosis (PCA) in Wistar rats resulted in a dramatic increase in histamine concentration in hypothalamus and a smaller, but clearly pronounced, elevation in the rest of brain. Between 10 and 120 days following surgery, shunted rats exhibited a histamine level 2.4- to 13-fold higher in hypothalamus and 1.5- to 2.5-fold higher in the rest of brain as compared to their control, sham-operated pairs. There were no significant changes in histamine concentration in the other examined tissues. The increase in brain histamine could not be attributed to the inhibition of its degradation, because activity of histamine N-methyltransferase remained unchanged for at least 40 days. Although the activity of histidine decarboxylase also remained unchanged when measured at a saturating concentration of L-histidine, the increase in histamine content in brain seems to be due to its enhanced synthesis brought about by increased availability of L-histidine in the tissue, as indicated by two to four times higher concentrations of this amino acid in PCA rats.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1111/j.1471-4159.1991.tb02559.x | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Histamine H receptor blockade alleviates neuropathic pain through the regulation of glial cells activation.
Biomed Pharmacother
January 2025
Maj Institute of Pharmacology, Polish Academy of Sciences, Department of Neurochemistry, 12 Smetna Str., Krakow 31-343, Poland. Electronic address:
Neuropathic pain is a disorder affecting the somatosensory nervous system. However, this condition is also characterized by significant neuroinflammation, primarily involving CNS-resident non-neuronal cells. A promising target for developing new analgesics is histamine H receptor (HR); thus, we aimed to determine the influence of a novel HR antagonist/inverse agonist, E-98 (1-(7-(4-chlorophenoxy)heptyl)-3-methylpiperidine), on pain symptoms and glia activation in model of neuropathic pain in male mice (chronic constriction injury to the sciatic nerve).
View Article and Find Full Text PDF[Therapeutic effect and mechanism of Jingfang Granules on chronic fatigue syndrome based on intestinal flora and metabolomics].
Zhongguo Zhong Yao Za Zhi
December 2024
School of Pharmacy, Shandong University of Traditional Chinese Medicine Ji'nan 250355, China State Key Laboratory of Integration and Innovation of Classic Formula and Modern Chinese Medicine, Lunan Pharmaceutical Group Co., Ltd. Linyi 276005, China.
This study aims to investigate the protective effect and potential mechanism of Jingfang Granules(JF) on the mouse model of chronic fatigue syndrome(CFS). Mice were randomized into normal, model, and low-, medium-, and high-dose(0.9, 1.
View Article and Find Full Text PDFPotassium Current Signature of Neuronal/Glial Progenitors in Amniotic Fluid Stem Cells.
Cells
January 2025
Department of Chemistry, Biology and Biotechnologies, University of Perugia, Via dell'Elce di Sotto 8, 06123 Perugia, Italy.
Article Synopsis
- Amniotic fluid contains stem cells (AF-SCs) that have potential uses in regenerative medicine for treating various injuries and diseases.
- When exposed to basic Fibroblast Growth Factor (bFGF), AF-SCs show the ability to survive and migrate in a rat brain model, resembling characteristics of neuronal/glial progenitor cells.
- The study employs electrophysiological techniques to identify specific potassium currents in AF-SCs and confirms that histamine can influence calcium dynamics and potassium current activation in these cells.
Deficiency of histamine H receptors in parvalbumin-positive neurons leads to hyperactivity, impulsivity, and impaired attention.
Neuron
January 2025
Department of Pharmacology and Department of Pharmacy of the Second Affiliated Hospital, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, School of Basic Medical Sciences, Zhejiang University School of Medicine, Hangzhou 310058, China. Electronic address:
Attention deficit hyperactivity disorder (ADHD), affecting 4% of the population, is characterized by inattention, hyperactivity, and impulsivity; however, its neurophysiological mechanisms remain unclear. Here, we discovered that deficiency of histamine H receptor (HR) in parvalbumin-positive neurons in substantia nigra pars recticulata (PV) attenuates PV neuronal activity and induces hyperactivity, impulsivity, and inattention in mice. Moreover, decreased HR expression was observed in PV in patients with ADHD symptoms and dopamine-transporter-deficient mice, whose behavioral phenotypes were alleviated by HR agonist treatment.
View Article and Find Full Text PDFComparative analysis of adenosine 1 receptor expression and function in hippocampal and hypothalamic neurons.
Inflamm Res
January 2025
Medical Faculty and University Hospital, Institute of Neural and Sensory Physiology, Heinrich Heine University Düsseldorf, 40225, Düsseldorf, Germany.
Background: Adenosine, an ATP degradation product, is a sleep pressure factor. The adenosine 1 receptor (A1R) reports sleep need. Histaminergic neurons (HN) of the tuberomamillary nucleus (TMN) fire exclusively during wakefulness and promote arousal.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!