Chemical inactivation of the nucleus tractus solitarius abolished hepatojejunal reflex in the rat

Abstract Objectives The aim of the present study was to validate a commercially available automated assay for the measurement of total adenosine deaminase (tADA) and its isoenzymes (ADA1 and ADA2) in saliva in a fast and accurate way, and evaluate the possible changes of these analytes in individuals with SARS-CoV-2 infection. Methods The validation, in addition to the evaluation of precision and accuracy, included the analysis of the effects of the main procedures that are currently being used for SARS-CoV-2 inactivation in saliva and a pilot study to evaluate the possible changes in salivary tADA and isoenzymes in individuals infected with SARS-CoV-2. Results The automated assay proved to be accurate and precise, with intra- and inter-assay coefficients of variation below 8.2%, linearity under dilution linear regression with R2 close to 1, and recovery percentage between 80 and 120% in all cases. This assay was affected when the sample is treated with heat or SDS for virus inactivation but tolerated Triton X-100 and NP-40. Individuals with SARS-CoV-2 infection (n=71) and who recovered from infection (n=11) had higher mean values of activity of tADA and its isoenzymes than healthy individuals (n=35). Conclusions tADA and its isoenzymes ADA1 and ADA2 can be measured accurately and precisely in saliva samples in a rapid, economical, and reproducible way and can be analyzed after chemical inactivation with Triton X-100 and NP-40. Besides, the changes observed in tADA and isoenzymes in individuals with COVID-19 open the possibility of their potential use as non-invasive biomarkers in this disease.

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Modulation of brown adipose tissue-mediated thermogenesis by lesions to the nucleus tractus solitarius in the rat

Brain Research ◽

10.1016/0006-8993(91)91482-g ◽

1991 ◽

Vol 546 (2) ◽

pp. 203-210 ◽

Cited By ~ 9

Author(s):

Doreen M. Fyda ◽

Keith E. Cooper ◽

Warren L. Veale

Keyword(s):

Adipose Tissue ◽

Brown Adipose Tissue ◽

Nucleus Tractus Solitarius ◽

Brown Adipose

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Effects of vasopressin on baroreceptor reflex in the area postreme and nucleus tractus solitarius

The Japanese Journal of Pharmacology ◽

10.1016/s0021-5198(19)44862-2 ◽

1997 ◽

Vol 73 ◽

pp. 89

Author(s):

Keisuke Migita ◽

Nobuaki Hori ◽

Ryou Saito ◽

Kenji Yamamoto ◽

Yukio Takano ◽

...

Keyword(s):

Nucleus Tractus Solitarius ◽

Baroreceptor Reflex

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Electrophysiological evidence that systemic angiotensin influences rat area postrema neurons

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1990.258.1.r70 ◽

1990 ◽

Vol 258 (1) ◽

pp. R70-R76 ◽

Cited By ~ 3

Author(s):

S. Papas ◽

P. Smith ◽

A. V. Ferguson

Keyword(s):

Nucleus Tractus Solitarius ◽

Area Postrema ◽

Cell Types ◽

Male Rats ◽

Ang Ii ◽

Adrenergic Agonist ◽

Arterial Blood ◽

Spontaneous Activities ◽

Single Unit Recordings ◽

Body Fluid Balance

Extracellular single-unit recordings from neurons in the area postrema (AP) and the nucleus tractus solitarius (NTS) in anesthetized male rats demonstrated that most cells in these regions have spontaneous activities of 5 Hz or less. Systemic angiotensin (ANG II) (50-500 ng) enhanced the activity of 55% of AP cells tested (n = 76), whereas 53% of tested NTS neurons (n = 62) were inhibited by ANG II. To determine whether these neurons were influenced specifically by circulating ANG II or by the accompanying increase in mean arterial blood pressure (BP), the effects of adrenergic agonists given intravenously on ANG II influenced neurons were also examined. Subsequently two cell types were characterized: cells responding to iv ANG II but not to the adrenergic agonist ("ANG II sensitive") and cells responding in a similar way to both agents ("BP sensitive"). Most ANG II-responsive neurons in the AP (53.5%) and the NTS (65%) were determined to be BP sensitive. These data demonstrate that ANG II influences the activity of AP neurons. In addition, there exists a second population of AP neurons apparently responsive to perturbations of the cardiovascular system. These studies further emphasize the potential roles of the AP in the regulation of body fluid balance.

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Behavioral analysis of anorexia produced by hindbrain injections of AMPA receptor antagonist NBQX in rats

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.2002.282.1.r147 ◽

2002 ◽

Vol 282 (1) ◽

pp. R147-R155 ◽

Cited By ~ 12

Author(s):

Huiyuan Zheng ◽

Christiane Patterson ◽

Hans-Rudolf Berthoud

Keyword(s):

Nucleus Tractus Solitarius ◽

Burst Size ◽

Lick Rate ◽

Ingestive Behavior ◽

Receptor Subtypes ◽

General Role ◽

Motor Processing ◽

Descending Facilitation ◽

Response Measures ◽

Integrative Process

The caudal brain stem integrates short-term feedback signals from the oral cavity and the food-handling abdominal viscera, as well as long-term homeostatic, cognitive, and emotional signals from the forebrain, to control ingestive behavior. Glutamate, acting on various receptor subtypes, plays a prominent role in this integrative process. Fourth ventricular injection of the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA)/kainate receptor blocker 1,2,3,4-tetrahydro-6-nitro-2,3-dioxobenzo[ f]quinoxaline-7-sulfonamide (NBQX, 0.5–5 nmol/3 μl) dose dependently suppressed intake of 15% sucrose in food-deprived and non-food-deprived rats compared with saline injection. Two consecutive paired NBQX injections (5 nmol) into the fourth ventricle did not produce conditioned taste aversion to saccharin, but LiCl did. Intraburst lick rate and lick efficiency were not affected, but burst size and number and initial lick rate were significantly decreased by NBQX. Local injection of NBQX (2 nmol) into and near the nucleus tractus solitarius also suppressed sucrose intake. These results suggest a general role for non- N-methyl-d-aspartate receptors in the transmission of positive (feedforward) signals, but do not identify the exact processing step involved, such as taste input, sensory-motor processing, or descending facilitation. More localized injections and response measures will be necessary.

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