No abstract

Giant anteater (Myrmecophaga tridactyla) is a wild mammal distributed in Central and South America; nowadays, it is classified as an endangered species. Research about the macroscopic and histomorphological aspects of its respiratory tract is scarce, and, sometimes, it limits the treatment provided to sick animals and impairs species preservation. Thus, the present study aims to describe the macroscopic and microscopic morphology of its lower respiratory tract, including trachea and lungs. To do so, 12 adult giant anteaters from “Centro de Triagem de Animais Silvestres de Goiânia” (CETAS-GO), Goiás State, Brazil, were used in the research after natural death or euthanasia. Three of these animals were used for macroscopic assessments; they were fixed in 10% buffered formalin and dissected. Trachea and lung tissue samples were collected from nine animals right after death and fixed in 10% buffered formalin for histomorphological analysis; they were processed, embedded in paraffin, and inked with hematoxylin-eosin (HE), periodic acid-Schiff (PAS), and Masson’s trichrome. The macroscopic analysis showed that the trachea in this species is proportionally short and presents from 19 to 27 tracheal cartilages. The right lung presents four lobes and the left one, two. The microscopic analysis evidenced respiratory epithelium of the ciliated cylindrical pseudostratified type, without evident goblet cells in the mucosa layer of the trachea and bronchi. The pulmonary visceral pleura is thick, similar to other large domestic mammals - complete septa extend from the pulmonary visceral pleura. In conclusion, the macroscopy and histomorphology of giant anteater’s lower respiratory tract, represented by trachea and lungs, are similar to that of other domestic and wild mammals. Pulmonary histomorphology is mainly similar to that of pigs and ruminants: it has thick visceral pleura that emits complete septa of conjunctive tissue, which enable lobular parenchymal architecture.

Giant anteater (Myrmecophaga tridactyla) is an endangered species that resides in much of Latin America, but it has been losing its habitat, especially in the Cerrado biome, where it constantly suffers traumas resulting from fires and roadkill. The anatomical knowledge of structures of the respiratory system is important for a better morphophysiological understanding of the species. Thus, this study aimed to perform the macroscopic and histomorphological description of the pharynx and larynx of the giant anteater. Twelve adult giant anteaters were used, three of them fixed in buffered formalin for further dissection and pharynx and larynx macroscopic analysis of structures. From the other animals, samples of the pharynx and larynx were collected and prepared for histological evaluation under optical microscope. Macroscopically, their pharynx and soft palate are extensive, and the anatomical location of these structures and the larynx differs greatly from that described in other species. The larynx, although more caudal, was similar to that of other animals. Histologically, the epithelium of these regions varied between the pseudostratified ciliated columnar and the non‐keratinized stratified squamous epithelium. Laryngeal cartilages were composed of elastic (epiglotti) and hyaline cartilages (arytenoid, cricoid and thyroid cartilage), with an ossification process and glandular clusters around the hyaline cartilage. The distinct anatomical location of the pharynx and larynx of Myrmecophaga tridactyla is the main macroscopic finding of this study, besides the length of the pharynx and soft palate of these animals.

The elastic cartilage is composed by chondroblasts and chondrocytes, extracellular matrix and surrounded by perichondrium. It has a low regeneration capacity and is a challenge in surgical repair. One of obstacles in engineering a structurally sound and long-lasting tissue is selecting the most appropriate scaffold material. One of the techniques for obtaining biomaterials from animal tissues is the decellularization that decreases antigenicity. In this work, alkaline solution was used in bovine ear elastic cartilages to evaluate the decellularization and the architecture of the extracellular matrix. The cartilages were treated in alkaline solution (pH13) for 72 hours and lyophilized to be compared with untreated cartilages by histological analysis (hematoxylin-eosin, Masson's trichrome and Verhoeff slides). Areas of interest for cell counting and elastic fiber quantification were delineated, and the distribution of collagen and elastic fibers and the presence of non-fibrous proteins were observed. The results demonstrated that the alkaline solution caused 90% decellularization in the middle and 13% in the peripheral region, and maintenance of the histological characteristics of the collagen and elastic fibers and non-fibrous protein removal. It was concluded that the alkaline solution was efficient in the decellularization and removal of non-fibrous proteins from the elastic cartilages of the bovine ear.

RESUMO O cerrado está presente em diferentes regiões do país e apresenta abundante biodiversidade de flora, apresentando diversos tipos de plantas que são muito utilizadas na medicina popular para o tratamento de enfermidades. O pequi é fruto do pequizeiro, pertencente à família Caryocaraceae, árvore frutífera e característica da região do cerrado. Essa espécie desenvolve importante papel para os habitantes destas regiões devido à utilização tanto do arbusto quanto do fruto para diferentes atividades econômicas. Devido ao valor terapêutico das diferentes partes do fruto, este assunto vem sendo pesquisado para comprovação da sua eficácia já que, por exemplo, no óleo do pequi existem diferentes substâncias com capacidade antimicrobianana, antiinflamatória e cicatrizante. Um dos componentes do pequi, os ácidos graxos, são considerados mediadores anti-inflamatórios e auxiliam no processo de cicatrização. Deste modo, com esta revisão objetiva-se reunir informações sobre a composição do óleo de pequi e dos mecanismos bioquímicos e fisiológicos que estão envolvidos na medicina popular e experimental, no que diz respeito à ação anti-inflamatória e cicatricial.