Mast Cells in the Mammalian Testis and Epididymis-Animal Models and Detection Methods

Mast cells (MCs) are an evolutionary well-conserved type of cells, mediating and modulating allergic responses in innate immunity and tissue remodeling after chronic inflammation. Among other tissues, they inhabit both the testis and epididymis. In the testis, MCs usually appear in the interstitial compartment in humans, but not in other standard experimental models, like rats and mice. MCs seem to be responsible for testicular tissue fibrosis in different causes of infertility. Although experimental animal models follow the effect on MC activation or penetration to the interstitial tissue like in humans to some extent, there is an inconsistency in the available literature regarding experimental design, animal strain, and detection methods used. This comprehensive review offers an insight into the literature on MCs in mammalian testes and epididymides. We aimed to find the most suitable model for research on MC and offer recommendations for future experimental designs. When using in vivo animal models, tunica albuginea incorporation and standard histological assessment need to be included. Domesticated boar strains kept in modified controlled conditions exhibit the highest similarity to the MC distribution in the human testis. 3D testicular models are promising but need further fine-tuning to become a valid model for MC investigation.

Changes in microcirculation induced by autotransplantation of skin flaps in experimental diabetes mellitus rats

Introduction. Micro- and macroangiopathies significantly reduce the duration and quality of life for diabetes mellitus (DM) patients, which determines the relevance of developing new ways to treat them, including non-drug ones. One of such methods is the autotransplantation of full-thickness skin flap providing a distant stimulating effect on microcirculation.

The aim of the study was to investigate the influence of skin flap autotransplantation on microcirculation at alloxan insulin deficiency in white rats.

Material and methods. The studies were carried out on 60 male scrub rats divided into the following groups: the control group, the comparison group (alloxan diabetes rats), the experimental group consisting of alloxan diabetes animals which had skin flap autotransplantations performed on them. Skin microcirculation (MC) of the dorsum of the feet was studied by laser Doppler flowmetry.

Results. Alloxan insulin deficiency caused a violation of the MC in rats which manifested by a decrease in perfusion of the skin of the dorsum of the foot in association with a decrease in the amplitudes of endothelial and neurogenic oscillations. On the 42nd day of the experiment in alloxan diabetes animals which had skin flap autotransplantations performed on them the statistically significant increase (p=0.000001) in the perfusion index by 43 % was observed attesting to microcirculation improvment. This was accompanied by an increase in the normalized amplitudes value of endothelial (by 44 %, р=0.000047) and neurogenic (by 20 %, р=0.019515) perfusion fluctuations relative to rats of the comparison group.

Conclusions. It can be concluded that skin flap autotransplantation has a positive effect on the state of MC in the feet in experimental diabetes rats due to the improvement of tissue perfusion and modulation of its activity.