No abstract

The neuroendocrine system regulates several organic functions such as reproduction, metabolism and adaptation to the environment. This system shows seasonal changes linked to the environment. The experimental model used in the present study was Lagostomus maximus maximus (viscacha). The reproduction of males of this species is photoperiod dependent. Twenty-four adult male viscachas were captured in their habitat at different times during one year. The adrenal glands were processed for light microscopy. Serial cuts were stained with hematoxylin-eosin for the morphometric study, and 100 nuclei of each zone of the adrenal cortex were counted per animal. Data were analyzed statistically by ANOVA and the Tukey test. The cells of the glomerulosa zone are arranged in a tube-shaped structure. The fasciculata zone has large cells with central nuclei and clearly visible nucleoli and with a vacuolar cytoplasm. In the reticularis zone there are two of types of cells, one with a nucleus of fine chromatin and a clearly visible nucleolus and the other with nuclear pycnosis. Morphometric analysis showed maximum nuclear volumes during the FebruaryMarch period with values of 133 ± 7.3 µm 3 for the glomerulosa, 286.4 ± 14.72 µm 3 for the fasciculata, and 126.3 ± 9.49 µm 3 for the reticularis. Minimum nuclear volumes were observed in August with values of 88.24 ± 9.9 µm 3 for the glomerulosa, 163.7 ± 7.78 µm 3 for the fasciculata and 64.58 ± 4.53 µm 3 for the reticularis. The short winter photoperiod to which viscacha is subjected could inhibit the adrenal cortex through a melatonin increase which reduces the nuclear volume as well as the cellular activity.

The food industry currently uses different compounds to satisfy the palatability of food without providing calories, including non‐nutritive sweeteners such as sucralose. The consumption of sucralose has increased in the last few years, not only in patients with obesity or type 2 diabetes, but also in the general population. Since sweeteners are designed to give flavor without providing calories, it is conceivable these compounds might also affect cellular metabolism. The immune system is the main defense of the organism and requires energy to perform its functions. Therefore, the purpose of this study is to determine changes in leucocytes populations in spleen, thymus and lymphatic nodes in mice that consumed commercial sucralose for a prolonged period of time. 14 week‐old BALB/c mice consumed ad libitum commercial sucralose in daily water for 6 weeks. After treatment, leukocytes from the selected organs were harvested and the subpopulations were analyzed by flow cytometry using the surface markers CD3, CD4, CD8, CD19 and CD16. Our preliminary results show no differences between leukocyte subpopulations in the spleen. We found an increase in the number of both CD4+ and CD8+ lymphocytes in the thymus in the sucralose group. Finally, we observed an increase in the number of NK cells in the lymph nodes in the same group. Our results suggest that chronic consumption of commercial sucralose may affect leukocyte subpopulations in the thymus and lymph nodes; however, further work is necessary to determine the effect of chronic sweetener intake on the activation capacity and effector functions of these cells.

Sweeteners are used in many food products like additives. In the last few years, ingestion of both nutritive and non‐nutritive sweeteners (NNS) has considerably increased. In addition, the general population has also increased its NNS intake, without a specific nutritional recommendation for doing so, as opposed to people suffering from non‐communicable diseases such as obesity, diabetes mellitus and hypertension. Chronic intake of these compounds may indirectly affect cellular metabolism. The main defense for the organism is the immune system, in which energy availability has an impact on cellular populations and their activation capacity. For this reason, it is necessary to determine the effect of frequent intake of NNS on the effector capacity of immune cells. The objective of this research is to determine changes in leukocyte populations and their expression of surface markers in the spleen of mice supplemented with commercial sucralose. 14 week‐old BALB/c mice ingested commercial sucralose ad libitum in daily water for 6 weeks. Leukocytes were isolated from spleen and we performed flow cytometry using the surface markers CD3, CD19, CD16 and CD14 for leukocyte subpopulations, along with CTLA‐4, PD1, CD40L, MHC‐I, MHC‐II, CD80 and CD86. Our results show a decrease in the frequency of B lymphocyte population and T lymphocytes in comparison to the control group. In B and T lymphocytes the analysis of co‐stimulatory molecules show a lower frequency compared to the control group. The immune response depends of the differentiation and activation of cellular populations. We hypothesized that chronic ingestion of commercial sucralose might be affecting the immune response by modifying the frequencies of cellular populations, as well as the expression of co‐stimulatory and inhibitory molecules such as MHC‐I, MHC‐II and PD1, by decreasing the ability of co‐stimulation between B an T lymphocytes, with a probable effect on the immune response. It is necessary to further determine if sucralose intake affects the efficiency of the immune response.