scholarly journals Adrenergic alpha-2 receptor antagonists cease augmented oxidation of plasma proteins and anxiety of rats caused by chronic noise exposure

2020 ◽  
Vol 22 (106) ◽  
pp. 63
Author(s):  
AshkhenLyova Manukyan ◽  
MariamVaros Manukyan ◽  
ArtemSergey Grigoryan ◽  
LilitSerob Hunanyan ◽  
HaykAshot Harutyunyan ◽  
...  
Life Sciences ◽  
1996 ◽  
Vol 58 (21) ◽  
pp. 1839-1847 ◽  
Author(s):  
Jinshyun R. Wu-Wong ◽  
William J. Chiou ◽  
Daniel J. Huffman ◽  
Martin Winn ◽  
Thomas W. von Geldern ◽  
...  

2001 ◽  
Vol 2 (1_suppl) ◽  
pp. S54-S58 ◽  
Author(s):  
Marc P Maillard ◽  
Catherine Centeno ◽  
Åsa Frostell-Karlsson ◽  
Hans R Brunner ◽  
Michel Burnier

Introduction Angiotensin II AT 1-receptor antagonists are highly bound to plasma proteins (≥ 99%). With some antagonists, such as DuP-532, the protein binding was such that no efficacy of the drug could be demonstrated clinically. Whether protein binding interferes with the efficacy of other antagonists is not known. We have therefore investigated in vitro how plasma proteins may affect the antagonistic effect of different AT1-receptor antagonists. Methods A radio-receptor binding assay was used to analyse the interaction between proteins and the ability of various angiotensin II (Ang II) antagonists to block AT1-receptors. In addition, the Biacore technology, a new technique which enables the real-time monitoring of binding events between two molecules, was used to evaluate the dissociation rate constants of five AT1-receptor antagonists from human serum albumin. Results The in vitro AT 1-antagonistic effects of different Ang II receptor antagonists were differentially affected by the presence of human plasma, with rightward shifts of the IC50 ranging from one to several orders of magnitude. The importance of the shift correlates with the dissociation rate constants of these drugs from albumin. Our experiments also show that the way that AT1-receptor antagonists bind to proteins differs from one compound to another. These results suggest that the interaction with plasma proteins appears to modulate the efficacy of some Ang II antagonists. Conclusion Although the high binding level of Ang II receptor antagonist to plasma proteins appears to be a feature common to this class of compounds, the kinetics and characteristics of this binding is of great importance. With some antagonists, protein binding interferes markedly with their efficacy to block AT1-receptors.


Author(s):  
M. Kraemer ◽  
J. Foucrier ◽  
J. Vassy ◽  
M.T. Chalumeau

Some authors using immunofluorescent techniques had already suggested that some hepatocytes are able to synthetize several plasma proteins. In vitro studies on normal cells or on cells issued of murine hepatomas raise the same conclusion. These works could be indications of an hepatocyte functionnal non-specialization, meanwhile the authors never give direct topographic proofs suitable with this hypothesis.The use of immunoenzymatic techniques after obtention of monospecific antisera had seemed to us useful to bring forward a better knowledge of this problem. We have studied three carrier proteins (transferrin = Tf, hemopexin = Hx, albumin = Alb) operating at different levels in iron metabolism by demonstrating and localizing the adult rat hepatocytes involved in their synthesis.Immunological, histological and ultrastructural methods have been described in a previous work.


2019 ◽  
Vol 4 (6) ◽  
pp. 1418-1422
Author(s):  
Bre Myers ◽  
J. Andrew Dundas

Purpose The primary aim of the current article is to provide a brief review of the literature regarding the effects of noise exposure on the vestibular and balance control systems. Although the deleterious effects of noise on the auditory system are widely known and continue to be an active area of research, much less is known regarding the effects of noise on the peripheral vestibular system. Audiologists with working knowledge of how both systems interact and overlap are better prepared to provide comprehensive care to more patients as assessment of both the auditory and vestibular systems has been in the audiologists' scope of practice since 1992. Method A narrative review summarizes salient findings from the archival literature. Results Temporary and permanent effects on vestibular system function have been documented in multiple studies. Hearing conservation, vestibular impairment, and fall risk reduction may be more intimately related than previously considered. Conclusions A full appreciation of both the vestibular and auditory systems is necessary to address the growing and aging noise-exposed population. More cross-system studies are needed to further define the complex relationship between the auditory and vestibular systems to improve comprehensive patient care.


1976 ◽  
Vol 19 (2) ◽  
pp. 216-224 ◽  
Author(s):  
James T. Yates ◽  
Jerry D. Ramsey ◽  
Jay W. Holland

The purpose of this study was to compare the damage risk of 85 and 90 dBA of white noise for equivalent full-day exposures. The damage risk of the two noise levels was determined by comparing the temporary threshold shift (TTS) of 12 subjects exposed to either 85 or 90 dBA of white noise for equivalent half- and full-day exposures. TTS was determined by comparing the pre- and postexposure binaural audiograms of each subject at 1, 2, 3, 4, 6, and 8 kHz. It was concluded that the potential damage risk, that is, hazardous effect, of 90 dBA is greater than 85 dBA of noise for equivalent full-day exposures. The statistical difference between the overall effects of equivalent exposures to 85 dBA as compared to 90 dBA of noise could not be traced to any one frequency. The damage risk of a full-day exposure to 85 dBA is equivalent to that of a half-day exposure to 90 dBA of noise. Within the limits of this study, TTS t was as effective as TTS 2 for estimating the damage risk of noise exposure.


2015 ◽  
Vol 16 (1) ◽  
pp. 15-24
Author(s):  
Vance Gunnell ◽  
Jeff Larsen

Hearing thresholds and distortion product otoacoustic emissions were measured for teachers of vocal performance who were gathered for a national conference. Results showed mean audiometric thresholds to be consistent with noise induced hearing loss, more than what would be expected with normal aging. Years of instruction and age were considered as factors in the hearing loss observed. It was concluded that hearing conservation should be initiated with this group to help raise awareness and protect them from hearing loss due to occupational noise exposure.


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