Superoxide-producing thermostable associate from the small intestines of control and alloxan-induced diabetic rats: quantitative and qualitative changes

R M Simonyan; K V Simonyan; G M Simonyan; H S Khachatryan; M A Babayan; M H Danielyan; L V Darbinyan; M A Simonyan

doi:10.1186/s12902-022-01160-x

Superoxide-producing thermostable associate from the small intestines of control and alloxan-induced diabetic rats: quantitative and qualitative changes

BMC Endocr Disord. 2022 Oct 18;22(1):250. doi: 10.1186/s12902-022-01160-x.

Authors

R M Simonyan¹, K V Simonyan², G M Simonyan¹, H S Khachatryan¹, M A Babayan¹, M H Danielyan³, L V Darbinyan⁴, M A Simonyan¹

Affiliations

¹ H. Buniatyan Institute of Biochemistry NAS RA, 0014, Yerevan, Armenia.
² Neuroendocrine Relationships Lab, Orbeli Institute of Physiology NAS RA, 0028, Yerevan, Armenia. karensimonyan86@gmail.com.
³ Histochemistry and Electron microscopy Lab, Orbeli Institute of Physiology NAS RA, 0028, Yerevan, Armenia.
⁴ Sensorimotor Integration Lab, Orbeli Institute of Physiology NAS RA, 0028, Yerevan, Armenia.

Abstract

Background: NADPH oxidase 1 (Nox1), which is highly expressed in the colon, is thought to play a potential role in host defense as a physical and innate immune barrier against commensal or pathogenic microbes in the gastrointestinal epithelium. Diabetes can be caused by several biological factors, including insulin resistance is one of them. Alloxan is widely used to induce insulin-dependent diabetes in experimental animals. Alloxan increases the generation of reactive oxygen species as a result of metabolic reactions in the body, along with a massive increase in cytosolic calcium concentration.

Methods: Using a universal method, a superoxide radical (О₂^-)-thermostable associate between NADPH-containing lipoprotein (NLP) and NADPH oxidase (Nox)- NLP-Nox was isolated and purified from the small intestine (SI) of control (C) and alloxan-induced diabetic (AD) albino rats.

Results: In comparison to the C indices, in AD in the SI, an increase in the specific content of NLP-Nox associate and a decrease in the stationary concentration of produced О₂^- in liquid phase (in solution) and gas phase (during blowing by oxygen of the NLP-Nox solution) were observed. The NLP-Nox of SI associate in C and AD rats produced О₂^- by an immediate mechanism, using NLP as a substrate. The phenomenon of the hiding of the optical absorption maxima of the Nox in oxidized states at pH10,5 was observed in the composition of these SI associates of the C and AD rat groups. The characteristic absorption maxima of the «hidden» Nox were observed under these conditions after reduction by potassium dithionite.

Conclusion: Thus, at AD, the decrease in the stationary concentration of produced О₂^- in the solution and gas phase was compensated for by an increase in the specific amount of associate. In addition, the decrease in the stationary concentration of produced О₂^- by NLP-Nox associates at AD can be linked to a decrease in the level of NADPH in NLP-Nox composition. This could be used as a new mechanism of AD pathogenesis.

Keywords: Alloxan diabetes; Associate; Small intestine; Superoxide.

MeSH terms

Alloxan
Animals
Calcium
Diabetes Mellitus, Experimental*
Dithionite
Insulins*
Intestine, Small / metabolism
Lipoproteins
NADP / metabolism
NADPH Oxidase 1
NADPH Oxidases / metabolism
Oxygen
Potassium
Rats
Reactive Oxygen Species / metabolism
Superoxides / metabolism

Substances

Alloxan
Calcium
Dithionite
Insulins
Lipoproteins
NADP
NADPH Oxidase 1
NADPH Oxidases
Oxygen
Potassium
Reactive Oxygen Species
Superoxides