Ultrastructural changes in type 2 alveolocytes in young rats on the background of chronic hyperglycemia

Introduction

Diabetes mellitus (DM) is considered as a group of metabolic diseases with a global distribution and severe complications. It is caused by insulin deficiency, which with time leads to development of pathological changes in the cardiovascular, respiratory, and other systems. Several studies have shown some features and the connection of structural changes of the lungs with DM, however very little is known regarding ultrastructural changes of type 2 alveolocytes (AT2).

Materials and methods

The study involved 24 white non-linear male laboratory rats which were divided into two groups (experimental and intact). The experimental group was further divided into two subgroups depending on the duration of study: the first group with hyperglycemia for 30 days, and the second with hyperglycemia for 60 days. For the experimental modeling of hyperglycemia, the rats were injected once subcutaneously with solution of alloxan monohydrate hyperglycemia.

Results

AT2 of the intact group had a high degree of differentiation with plates of high electron density. In AT2 of rats with hyperglycemia for 30 days, there were signs of vacuolation, mass accumulation of primary and secondary lysosomes, and lamellar bodies were grouped as conglomerates. In AT2 of the rats with 60 days of hyperglycemia, nuclei with scalloped contour, karyoplasmic outgrowths and intussusception, and condensation of heterochromatin were observed.

Conclusion

Under conditions of experimental chronic hyperglycemia, proliferation and destruction of AT2 are observed, which is the morphological basis for the violation of surfactant synthesis and immunocompetent properties in lung tissues of young rats.