Sex-Specific Differences of Adenosine Triphosphate Levels in Red Blood Cells Isolated From ApoE/LDLR Double-Deficient Mice

Secondary structure alterations of RBC assessed by FTIR-ATR in correlation to 2,3-DPG levels in ApoE/LDLR-/- Mice

In the present study, we characterized the secondary structure alterations of intact red blood cells (RBCs) cytosol with special attention to the sex-related alterations in 8- and 24-week-old female and male ApoE/LDLR^-/- mice, compared to age-matched female and male C57BL/6J control animals. Results were obtained with previously established methodology based on Fourier transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR). Additionally, we evaluated 2,3-DPG levels in the RBCs and showed its potential link to the hemoglobin (Hb) secondary structure alterations. Considering Hb structure alterations probed by FTIR-ATR, the ratio of turns to α-helices in 8-week-old ApoE/LDLR^-/- mice suggested more pronounced secondary structure alterations within the RBCs than in the age-matched control. Sex-related differences were observed solely in 24-week-old male ApoE/LDLR^-/- mice, which showed statistically significant increase in the secondary structure alterations compared to 24-week-old female ApoE/LDLR^-/- mice. Similar to the secondary structure alterations, no sex-related differences were observed in the levels of 2,3-DPG in RBCs, except for 24-week-old male ApoE/LDLR^-/- mice, which showed significantly higher levels compared to the age-matched female ApoE/LDLR^-/- mice. Considering the age-related alterations, we observed significant increases in the intracellular 2,3-DPG of RBCs with animals' age in all studied groups, except for female ApoE/LDLR^-/- mice, where a significant difference was not reported. This suggests the clear correlation between secondary structure of Hb alterations and 2,3-DPG levels for male and female murine RBC and proves a higher resistance of older female RBCs to the secondary structure changes with progression of atherosclerosis. Moreover, it may be concluded that higher 2,3-DPG levels in RBCs occurred in response to the secondary structure alterations of Hb in ApoE/LDLR^-/- mice.

Comparison of volatile compounds of anal sac secretions between the sexes of domestic dog (Canis lupus familiaris)

Volatile compounds of anal sac secretions are odorant chemicals used across the carnivores for social communication such as identifying individuals and group membership. Odor profiles taken from expressed anal sac secretions of some species of carnivores have been detected in previous studies. In this study, the volatile compounds of anal sac secretions between five male and five female domestic dogs (Canis lupus familiaris) were compared. Volatile chemicals were extracted, separated, and analyzed by gas chromatography-mass spectrometry with solid-phase micro-extraction and identified from their electron ionization mass spectra and Kovats retention indices. The results showed the presence of various types of compounds including organic fatty acids, ketones, aldehydes, esters, and alcohols in the anal sac secretions of dogs. Greater amounts of diversity and esters, and lower amounts of alcohols were detected in the anal sac secretions of females compared to males. This was accompanied by finding citrate and acetic acid ester only in the females. Furthermore, presence of some sex-specific organic compounds like dimethylcyclopentyl ethanone indicates that the volatile profiles of anal sac secretions in 10 domestic dogs are differentiated by host sex.