Long-term depletion of histamine in guinea-pigs by administration of α-fluoromethylhistidine, a specific inhibitor of histidine decarboxylase; effect on the sensitivity of histamine receptors

1988 ◽  
Vol 24 (1-2) ◽  
pp. 56-64 ◽  
Author(s):  
H. Fukuda ◽  
K. Maeyama ◽  
Y. Ito ◽  
T. Watanabe ◽  
H. Wada
Keyword(s):  
Guinea Pigs ◽  
Histidine Decarboxylase ◽  
Specific Inhibitor ◽  
Histamine Receptors

scholarly journals Short- and Long-Term Social Recognition Memory Are Differentially Modulated by Neuronal Histamine

Biomolecules ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 555
Author(s):  
Barbara Rani ◽  
Bruna Silva-Marques ◽  
Rob Leurs ◽  
Maria Beatrice Passani ◽  
Patrizio Blandina ◽  
...  
Keyword(s):  
Recognition Memory ◽  
Histamine Release ◽  
Histidine Decarboxylase ◽  
Acetylcholinesterase Inhibitor ◽  
Social Recognition ◽  
Amnesic Effect ◽  
Brain Histamine ◽  
Monogamous Species ◽  
Social Recognition Memory

The ability of recognizing familiar conspecifics is essential for many forms of social interaction including reproduction, establishment of dominance hierarchies, and pair bond formation in monogamous species. Many hormones and neurotransmitters have been suggested to play key roles in social discrimination. Here we demonstrate that disruption or potentiation of histaminergic neurotransmission differentially affects short (STM) and long-term (LTM) social recognition memory. Impairments of LTM, but not STM, were observed in histamine-deprived animals, either chronically (Hdc−/− mice lacking the histamine-synthesizing enzyme histidine decarboxylase) or acutely (mice treated with the HDC irreversible inhibitor α-fluoromethylhistidine). On the contrary, restriction of histamine release induced by stimulation of the H3R agonist (VUF16839) impaired both STM and LTM. H3R agonism-induced amnesic effect was prevented by pre-treatment with donepezil, an acetylcholinesterase inhibitor. The blockade of the H3R with ciproxifan, which in turn augmented histamine release, resulted in a procognitive effect. In keeping with this hypothesis, the procognitive effect of ciproxifan was absent in both Hdc−/− and αFMH-treated mice. Our results suggest that brain histamine is essential for the consolidation of LTM but not STM in the social recognition test. STM impairments observed after H3R stimulation are probably related to their function as heteroreceptors on cholinergic neurons.

4-Imidazolyl-3-amino-2-butanone (McN-A-1293), a new specific inhibitor of histidine decarboxylase

1973 ◽  
Vol 22 (18) ◽  
pp. 2299-2310 ◽  
Author(s):  
Russell J. Taylor ◽  
Franz J. Leinweber ◽  
George A. Braun
Keyword(s):  
Histidine Decarboxylase ◽  
Specific Inhibitor

scholarly journals EFFECT OF LOCAL UV RADIATION ON THE MORPHOFUNCTIONAL STATE OF THE SKIN OF GUINEA PIGS IN EARLY AND REMOTE PERIODS AFTER IRRADIATION

2020 ◽  
Vol 73 (4) ◽  
pp. 705-707
Author(s):  
Tetyana V. Zvyagintseva ◽  
Svitlana I. Myronchenko ◽  
Nataliia I. Kytsiuk ◽  
Olga V. Naumova
Keyword(s):  
Ultraviolet Irradiation ◽  
Guinea Pigs ◽  
Acute Inflammation ◽  
Elastic Fibers ◽  
Control Group ◽  
Entire Observation Period ◽  
Morphological Picture ◽  
Morphometric Methods ◽  
Observation Period

The aim is to establish the features of morphological and morphometric changes in the skin of guinea pigs in erythemal, early post-erythemal and late post-erythemic periods after local ultraviolet irradiation. Materials and methods: Studies were conducted on 54 albino guinea pigs weighing 400-500 g. Ultraviolet erythema was caused by irradiation in 1 minimum erythemal dose. The control group included intact guinea pigs. After 2, 4 hours, on the 3rd, 8th, 15th, 21st, 28th day, the fragments of the irradiated skin were investigated using histochemical and morphometric methods. Results: After 2, 4 hours after irradiation, dyscirculatory changes in the skin develop. By the 3rd day of the experiment a morphological picture of acute inflammation in the epidermis and dermis develops, apoptotic keratinocytes appear (sunburn cells), which is accompanied by thickening of the epidermis and an increase in the density of fibroblasts. By the 8th day proliferative-hyperplastic and degenerative changes begin to prevail, including dystrophic nature, the thickness of the epidermis and the density of fibroblasts reach a maximum. In the long term, on the 15-28th day, dystrophic changes of the epidermis, dyskeratosis, changes in the number and structure of elastic fibers with an increase in uneven fibrosis, collagenization processes and the development of sclerotic changes, as well as a significant thickening of the epidermis, an increase in the density of fibroblasts are observed. Conclusions: The data obtained indicate pronounced morphofunctional changes in the skin in the zone of local ultraviolet irradiation observed throughout the entire observation period.

scholarly journals Analysis of Aflatoxin Biomarkers in the Hair of Experimental Animals

Toxins ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 570
Author(s):  
Innocent Mupunga ◽  
Ilse Janse van Rensburg ◽  
Nokuthula Luthuli ◽  
Ovokeroye A. Abafe ◽  
Leshweni J. Shai ◽  
...  
Keyword(s):  
Guinea Pigs ◽  
Hair Analysis ◽  
Historical Record ◽  
Body Fluids ◽  
Urine Samples ◽  
Long Term Effects ◽  
Experimental Animals ◽  
Explorative Study ◽  
Hair Samples

Analysis of body fluids and tissues of aflatoxin exposed individuals for the presence of aflatoxins and aflatoxin metabolites has emerged as a reliable indicator of exposure and metabolism of aflatoxins. However, current aflatoxin biomarkers are not appropriate for investigating the long-term effects of aflatoxin exposure. In this explorative study, we investigated the analysis of hair as a complementary or alternative matrix for the assessment of biomarkers of long-term aflatoxin exposure. Three groups of guinea pigs were orally dosed with 5 ugkg−1bw−1, 50 ugkg−1bw−1, and 100 ugkg−1bw−1 of AFB1. Urine and hair samples were collected on days 0, 1, 2, 3, 7, 30, 60, and 90 and analysed for AFB1 and AFM1 using UHPLC-MS/MS. AFB1 and AFM1 were detected in 75% and 13.6%, respectively, of the day 1 to day 7 urine samples. AFB1 was detected in hair samples collected from day 3 up to day 60. This is the first report to confirm the deposition of AFB1 in the hair of experimental animals. These findings indicate that hair analysis has the potential to provide an accurate long-term historical record of aflatoxin exposure with potentially important implications for the field of aflatoxin biomarkers.

scholarly journals Hypoxanthine-Guanine Phosphoribosyltransferase Is Dispensable for Mycobacterium smegmatis Viability

2019 ◽  
Vol 202 (5) ◽  
Author(s):  
Zdeněk Knejzlík ◽  
Klára Herkommerová ◽  
Dana Hocková ◽  
Iva Pichová
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Mycobacterium Smegmatis ◽  
Model Organism ◽  
Specific Inhibitor ◽  
Purine Salvage ◽  
Content Type ◽  
Acyclic Nucleoside Phosphonates ◽  
Hypoxanthine Guanine Phosphoribosyltransferase

ABSTRACT Purine metabolism plays a ubiquitous role in the physiology of Mycobacterium tuberculosis and other mycobacteria. The purine salvage enzyme hypoxanthine-guanine phosphoribosyltransferase (HGPRT) is essential for M. tuberculosis growth in vitro; however, its precise role in M. tuberculosis physiology is unclear. Membrane-permeable prodrugs of specifically designed HGPRT inhibitors arrest the growth of M. tuberculosis and represent potential new antituberculosis compounds. Here, we investigated the purine salvage pathway in the model organism Mycobacterium smegmatis. Using genomic deletion analysis, we confirmed that HGPRT is the only guanine and hypoxanthine salvage enzyme in M. smegmatis but is not required for in vitro growth of this mycobacterium or survival under long-term stationary-phase conditions. We also found that prodrugs of M. tuberculosis HGPRT inhibitors displayed an unexpected antimicrobial activity against M. smegmatis that is independent of HGPRT. Our data point to a different mode of mechanism of action for these inhibitors than was originally proposed. IMPORTANCE Purine bases, released by the hydrolytic and phosphorolytic degradation of nucleic acids and nucleotides, can be salvaged and recycled. The hypoxanthine-guanine phosphoribosyltransferase (HGPRT), which catalyzes the formation of guanosine-5′-monophosphate from guanine and inosine-5′-monophosphate from hypoxanthine, represents a potential target for specific inhibitor development. Deletion of the HGPRT gene (Δhgprt) in the model organism Mycobacterium smegmatis confirmed that this enzyme is not essential for M. smegmatis growth. Prodrugs of acyclic nucleoside phosphonates (ANPs), originally designed against HGPRT from Mycobacterium tuberculosis, displayed anti-M. smegmatis activities comparable to those obtained for M. tuberculosis but also inhibited the Δhgprt M. smegmatis strain. These results confirmed that ANPs act in M. smegmatis by a mechanism independent of HGPRT.

Effect of Infrasound and Low Frequency Sound Exposure at Intensities below 100 dB(SPL) on the Rota-Rod Treadmill Performance of Guinea Pigs

1983 ◽  
Vol 2 (3) ◽  
pp. 37-41 ◽  
Author(s):  
Naoki Maehara ◽  
Reiko Kishi ◽  
Terukazu Sadamoto ◽  
Izumi Harabuchi ◽  
Kohtaroh Yamamura
Keyword(s):  
Guinea Pigs ◽  
Motor Coordination ◽  
Low Frequency ◽  
Vestibular Function ◽  
Moderate Intensity ◽  
Endurance Time ◽  
Frequency Sound ◽  
Sound Exposure ◽  
Preliminary Study

A preliminary study to investigate whether or not long-term exposure to very low frequency sound at a moderate intensity below 100 dB(SPL) affects the vestibular function and/or motor coordination in guinea pigs was carried out. At first, optimal conditions of Rota-Rod Treadmill performance for guinea pigs were determined. Then, 20 and 40 Hz-low frequency sound at 80–90 dB(SPL) exposure was used for 150 minutes and measurement of the endurance time on the Rota-Rod Treadmill was carried out at rotation speeds of 8 rpm or 10 rpm. At 10 rpm rotation speed, and 20 Hz, 90 dB(SPL) stimulus, the endurance time was significantly reduced at 150 minutes, compared with that of the control, whereas no significant reduction in endurance time was obtained at 85 dB(SPL).

Objective interpretation of dental disease in rabbits, guinea pigs and chinchillas

2009 ◽  
Vol 37 (04) ◽  
pp. 250-260 ◽  
Author(s):  
D. Crossley ◽  
E. Boehmer
Keyword(s):  
Guinea Pigs ◽  
Dental Disease ◽  
Post Mortem ◽  
Objective Interpretation ◽  
Skull Radiographs ◽  
Post Mortem Findings ◽  
Long Term Prognosis ◽  
Species Specific ◽  
Radiographic Changes

Summary Objective: Objective interpretation of dental disease in rabbits, guinea pigs and chinchillas with the use of anatomical reference lines. Material and methods: Skull radiographs (laterolateral and dorsoventral view) of 528 small mammals (204 rabbits, 151 guinea pigs and 173 chinchillas) were measured and analysed exactly in connection with a thorough intra- and extraoral clinical examination. 464 animals showed variable signs of malocclusion whereas 64 animals had a normocclusion. The clinical and radiographic changes of 224 individuals (52 rabbits, 41 guinea pigs and 131 chinchillas) were additionally compared with post mortem findings. Results: Particularly the comparison of the prepared skulls with the radiographs of the identical animals enabled the acquirement of species specific anatomical reference lines, that facilitate the objectice assessment of severity of dental disease in elodont species. Conclusion and clinical relevance: Using these reference lines the extent of malocclusion in rabbits, guinea pigs and chinchillas can be acquired more exactly and the results are reproducible by different examiners (staging). In addition to this these special lines facilitate to accurately monitor the progress of dental changes and thus to predict a probable long-term prognosis. The reference lines are absolutely applicable for daily use in practice.

scholarly journals A recombinant vesicular stomatitis-based Lassa fever vaccine elicits rapid and long-term protection from lethal Lassa virus infection in guinea pigs

npj Vaccines ◽  
2019 ◽  
Vol 4 (1) ◽  
Author(s):  
Derek R. Stein ◽  
Bryce M. Warner ◽  
Geoff Soule ◽  
Kevin Tierney ◽  
Kathy L. Frost ◽  
...  
Keyword(s):  
Virus Infection ◽  
Guinea Pigs ◽  
Lassa Fever ◽  
Lassa Virus ◽  
Vesicular Stomatitis

Long-term influence of enteric infection on jejunal propulsion in guinea pigs

1989 ◽  
Vol 97 (6) ◽  
pp. 1461-1468 ◽  
Author(s):  
Hassan Alizadeh ◽  
William A. Weems ◽  
Gilbert A. Castro
Keyword(s):  
Guinea Pigs ◽  
Enteric Infection
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