Angioarchitecture of collateral arteries of the aortic arch of Antillean manatee (Trichechus manatus manatus Linnaeus, 1758)

Age and sex effects on histological features and in vitro culturing of Antillean manatee (Trichechus manatus manatus, Linnaeus 1758) dermis

The biobanks from dermal biopsies represent an interesting strategy for biodiversity conservation. Nevertheless, the morphological and cellular patterns of the dermis can be influenced by the age and sex of the individual. Therefore, evaluating these factors is interesting for forming biobanks of Antillean manatees. These animals, representatives of marine fauna, have had their population reduced, and biobanks are essential for their conservation. Then, we evaluated the effects of age (3.5 years vs. 3.6-16 years vs. 23.6 years) and sex (males vs. females) on morphological and cellular parameters using histological and in vitro culture techniques. Regardless of age, no differences were observed for dermal thickness, collagen fibres, tissue proliferative activity and viable cell recovery. Nonetheless, fibroblast reduction was observed in groups aged 23.6 years compared to other animals (p < 0.05). Additionally, cells from animals aged 3.6-16 years showed more significant mitochondrial damage than the other groups (p < 0.05). Regardless of sex, no differences were observed for dermal thickness, collagen fibres, tissue proliferative activity and viable cell recovery; however, females had fewer fibroblasts than males (p < 0.05). Cells from females showed lower mitochondrial damage when compared to cells from males. In summary, although age and sex do not influence dermal thickness and cell recovery, variations in the number of fibroblasts and mitochondrial characteristics were observed among the groups. These differences may be significant for understanding the dermis aspects to be correlated to biobank systems.

Collateral aortic branches in the collared peccary (Pecari tajacu Linnaeus, 1758)

The determination of arterial vascular distribution patterns can contribute to more detailed knowledge on arterial systems. In this context, the aim of the present study was to describe the collateral aortic branches in the collared peccary, aiming to define a standard model for this species, providing information through comparative anatomy for analysis of some evolutionary aspects of the order Artiodactyla. Ten young male animals were employed. The vascular system was washed with a saline solution and then perfused with Neoprene 450 latex coloured with red or yellow pigment, followed by collateral aorta branch dissections and analyses. The contrasted digital radiography technique was applied to two animals, which were initially perfused with a barium sulphate solution (1 g/ml) and Neoprene 450 latex at a 1:3 ratio, and subsequently, the digital radiographic examination was performed. The aortic arch of the collared peccary emitted the brachiocephalic trunk and the left subclavian artery, while eight symmetric pairs of dorsal intercostal arteries originated from the thoracic aorta. The abdominal aorta, in turn, exhibited the celiac, cranial mesenteric, renal, caudal mesenteric, testicular, external iliac, internal iliac and sacral arteries as the collateral branches in all studied animals. Therefore, no relevant variations were observed regarding the arrangement of the arterial distribution of the aorta, thus suggesting a static standard model in the collared peccary.

Collateral arteries of the aortic arch of the red-rumped agouti (Dasyprocta leporina Linnaeus, 1758)

Detailed knowledge of the arterial system is an important prerequisite when interpreting experimental data in research, as well as in the diagnosis of cardiovascular disease using imaging techniques such as Doppler echocardiography and contrast radiography. Thus, considering the importance of the aortic arrangement, the objective of this study was to describe the collateral arteries of the aortic arch of agoutis in order to establish the standard model, and therefore contribute to studies involving research related to heart disease, and produce information for a more accurate diagnosis in complementary imaging examinations. In this study, 14 adult animals were used, comprising eight males and six females. The vascular system was washed with 0.9% aqueous saline solution and perfused with Neoprene 450 latex coloured with yellow or red pigment, which was subsequently dissected and analysed. One male animal was used for the digital contrast radiography technique perfused with a liquid barium sulphate solution (Bariogel^® ) (1 g/ml) and Neoprene 450 latex, both diluted 1/3. The aortic arch of the agouti presented with only the brachiocephalic trunk as collateral branch in all the animals studied. Thus, agouti falls into type 1 for mammalian aortic arch vascular arrangements.