Systematization of the brain base arteries in nutria (Myocastor coypus) / Sistematização das artérias da base do encéfalo em nutria (Myocastor coypus)

Background: The nutria (Myocastor coypus) is a medium-size, semi-aquatic rodent, valued in skin and meat industry. The brain circulation has been well studied in rodents but not in nutria. To understand and compare the phylogenetic development of the arteries of the base of the brain in rodents, this paper aims to describe and systematize these arteries, establishing a standard model and its main variations in nutria.Materials, Methods & Results: Following approval by the Ethics Committee of Federal University of Rio Grande do Sul, thirty nutrias from a commercial establishment authorized by Brazilian Institute of Environment and Natural Resources (IBAMA) were studied. For euthanasia, was applied heparin (10000 U.I for animal), intraperitoneally, and after thirty minutes the animals ware sedated with acepromazine (0.5 mg/kg) and meperidine (20 mg/kg), intramuscularly. After sedation, they were euthanized with thiopental sodium (120 mg/kg) and lidocaine (10 mg/mL), intraperitoneally. The heart was accessed, the cardiac apex was sectioned, the aorta was cannulated via the left ventricle and clamped close to the diaphragm, and the arterial system was washed with saline solution and filled with latex. The animals were submerged in water for latex polymerization, the trunk was sectioned, the skin removed and a bony window was opened in the skull vault. The pieces were fixed in formaldehyde. The brains were removed, and schematic drawings of the arteries from the base of the brain were made for elaboration of the results. The nutrias brain was vascularized by the vertebro-basilar system. The terminal branches of the right and left vertebral artery were anastomosed on the ventral surface of the medulla oblongata, forming the basilar artery, and caudally the ventral spinal artery.[...](AU)

Systematization of the brain base arteries in nutria (Myocastor coypus) / Sistematização das artérias da base do encéfalo em nutria (Myocastor coypus)

Background: The nutria (Myocastor coypus) is a medium-size, semi-aquatic rodent, valued in skin and meat industry. The brain circulation has been well studied in rodents but not in nutria. To understand and compare the phylogenetic development of the arteries of the base of the brain in rodents, this paper aims to describe and systematize these arteries, establishing a standard model and its main variations in nutria.Materials, Methods & Results: Following approval by the Ethics Committee of Federal University of Rio Grande do Sul, thirty nutrias from a commercial establishment authorized by Brazilian Institute of Environment and Natural Resources (IBAMA) were studied. For euthanasia, was applied heparin (10000 U.I for animal), intraperitoneally, and after thirty minutes the animals ware sedated with acepromazine (0.5 mg/kg) and meperidine (20 mg/kg), intramuscularly. After sedation, they were euthanized with thiopental sodium (120 mg/kg) and lidocaine (10 mg/mL), intraperitoneally. The heart was accessed, the cardiac apex was sectioned, the aorta was cannulated via the left ventricle and clamped close to the diaphragm, and the arterial system was washed with saline solution and filled with latex. The animals were submerged in water for latex polymerization, the trunk was sectioned, the skin removed and a bony window was opened in the skull vault. The pieces were fixed in formaldehyde. The brains were removed, and schematic drawings of the arteries from the base of the brain were made for elaboration of the results. The nutria’s brain was vascularized by the vertebro-basilar system. The terminal branches of the right and left vertebral artery were anastomosed on the ventral surface of the medulla oblongata, forming the basilar artery, and caudally the ventral spinal artery.[...]

Distribuição das artérias mesentéricas cranial e caudal na nutria (Myocastor coypus) / Distribution of Cranial and Caudal Mesenteric Arteries in Nutria (Myocastor coypus)

Background: The nutria (Myocastor coypus) is a semi-aquatic rodent, originating from the extreme south of South America, exploited for commercial purposes, in particular the quality of your skin and flesh. The objective of this study was to systematize and describe the cranial and caudal mesenteric arteries in the nutria. Materials, Methods & Results: To perform this study were used a total of 30 specimens of nutria, 15 females and 15 males. To the animals were administered heparin and after thirty minutes Thiopental Sodium, via an intraperitoneal injection, to perform euthanasia. The thoracic cavity was opened ventrally in plastron, the thoracic aorta was cannulated and the system was washed with saline solution. Then the system was filled with latex 603 colored in red and the animals remained immersed in running water for one hour. The skin was removed and then the trunk was transversally sectioned near the last thoracic vertebrae. The abdominal cavity remained closed and formaldehyde was administered via an intraperitoneal injection. The specimens were fixed in formaldehyde for seven days, the abdominal cavity was opened, the viscera were removed in block and the arteries were dissected. Statistical analyses of the results were performed using percentage values. It was observed that the abdominal aorta gave rise to the cranial and caudal mesenteric arteries. The cranial mesenteric artery originated as a standard the caudal pancreaticoduodenal, middle colic, right colic, ileocolic, jejunal arteries and ileal branches. The pancreaticoduodenal artery traveled the interior of mesoduodeno irrigating part of the body and the right lobe of the pancreas and the end of the duodenum. The middle colic artery bifurcated into right and left branches, going to irrigate the transverse and descending colon, respectively. The right colic artery gave a branch to the beginning of the ascending colon, small branches to the transverse colon and continued going through the loop formed by the ascending colon. The ileocolic artery emitted the cecal artery, ileal, ascending colic and cecum branches, for irrigation of the cecum, ileum and ascending colon. The jejunal arteries were responsible for the irrigation of the jejunum, ileum, and the last jejunal artery anastomosed with the ileal artery. The caudal mesenteric artery originated the left colic and cranial rectal arteries. Discussion: In this study and in others papers of nutria and chinchilla, we observed the cranial mesenteric artery originating from the abdominal aorta caudally to the celiac artery. The sequences of the origin of the branches of the cranial mesenteric artery were varied between rodent species and within them. In this study, and in another one of nutria, the caudal pancreaticoduodenal artery was predominantly double. In rodents, the middle colic artery was originated, as standard, from the cranial mesenteric artery, but this study showed that in one piece, this artery originated from the ileocolic artery. The terminal branch of middle colic artery was anastomosed in osculum with the left colic artery, branch of the caudal mesenteric artery in 46,7% of the sample, and this observation was also found in another articles of nutria (30%) and agouti (36,3%). The right colic artery emitted a colic branch to the top of the ascending colon and anastomosed in osculum to the colic branch of the ileocolic artery in 46.7% of the animals, and this anastomosis was also observed in agouti. The number of jejunal arteries varied widely inside and within species of rodents. The ileocolic artery vascularized the cecum, ileum and ascending colon in nutrias and agouti. The caudal mesenteric artery bifurcated into the left colic and cranial rectal artery in nutrias, agoutis, chinchillas, cavies and rabbits.

Persistência da veia cava cranial esquerda em cão / Persistent Left Cranial Vena Cava in a Dog

Background: Persistent left cranial vena cava with absent right cranial vena cava is a rare anomaly. Congenitally persistent left cranial vena cava is the most common variant of the systemic venous return to the heart, embryologically resulting from failure of the anterior cardinal vein in becoming obliterated. Persistent left cranial vena cava is the most common form of anomalous venous drainage involving the cranial vena cava, and represents persistence of the left horn of the embryonic sinus venosus, which normally involutes during normal development, becoming the coronary sinus. Usually, persistent left cranial vena cava enters the right atrium through the orifice of an enlarged coronary sinus. Persistent left cranial vena cava is an uncommon congenital cardiovascular anomaly in dogs, generally coexisting with other more serious cardiac defects. The condition is rare as an isolated single defect. The left cranial vena cava is observed only among domestic mammals, but it is a relatively rare anomaly that can be found in other species, including man, without causing clinical problems. The objective of this study was to report the occurence of a rare vascular formation of the cranial vena cava, which caused the persistence of the left cranial vena cava instead of the right one. Case: At the anatomy laboratory of the Faculty of Veterinary of the UFGRS, a male dog was identified with a persistent left cranial vena cava and absent right cranial vena cava.[...](AU)

Persistência da veia cava cranial esquerda em cão / Persistent Left Cranial Vena Cava in a Dog

Background: Persistent left cranial vena cava with absent right cranial vena cava is a rare anomaly. Congenitally persistent left cranial vena cava is the most common variant of the systemic venous return to the heart, embryologically resulting from failure of the anterior cardinal vein in becoming obliterated. Persistent left cranial vena cava is the most common form of anomalous venous drainage involving the cranial vena cava, and represents persistence of the left horn of the embryonic sinus venosus, which normally involutes during normal development, becoming the coronary sinus. Usually, persistent left cranial vena cava enters the right atrium through the orifice of an enlarged coronary sinus. Persistent left cranial vena cava is an uncommon congenital cardiovascular anomaly in dogs, generally coexisting with other more serious cardiac defects. The condition is rare as an isolated single defect. The left cranial vena cava is observed only among domestic mammals, but it is a relatively rare anomaly that can be found in other species, including man, without causing clinical problems. The objective of this study was to report the occurence of a rare vascular formation of the cranial vena cava, which caused the persistence of the left cranial vena cava instead of the right one. Case: At the anatomy laboratory of the Faculty of Veterinary of the UFGRS, a male dog was identified with a persistent left cranial vena cava and absent right cranial vena cava.[...]

A artéria celíaca em Didelphis albiventris (gambá) / The celiac artery in Didelphis albiventris (opossum)

This member of the Didelphidea family, commonly known as opossum, is widely distributed in the American territory, with species found from southern Canada up to northern Argentina. Similarly to all marsupials, they are characterized by a short gestational period, followed by a long development period. Opossums are arboreal, terrestrial slow animals of lonely and nocturnal habits. They are omnivore animals, eating from small rodents, birds, eggs and amphibians to fruits and vegetables. These general characteristics have drawn in the interest and curiosity of the scientific community to this animal, which is now the object of study in several knowledge areas. In order to find morphological information that could assist in discussions from a functional point of view and that could offer support for measures that aim at protecting opossums in their natural environment, the objective of the present study is to divulge the anatomical behavior of their celiac artery and its branches, including its distribution areas, considering the importance of these vessels in the blood supply of several digestive organs.

A artéria celíaca em Didelphis albiventris (gambá) / The celiac artery in Didelphis albiventris (opossum)

This member of the Didelphidea family, commonly known as opossum, is widely distributed in the American territory, with species found from southern Canada up to northern Argentina. Similarly to all marsupials, they are characterized by a short gestational period, followed by a long development period. Opossums are arboreal, terrestrial slow animals of lonely and nocturnal habits. They are omnivore animals, eating from small rodents, birds, eggs and amphibians to fruits and vegetables. These general characteristics have drawn in the interest and curiosity of the scientific community to this animal, which is now the object of study in several knowledge areas. In order to find morphological information that could assist in discussions from a functional point of view and that could offer support for measures that aim at protecting opossums in their natural environment, the objective of the present study is to divulge the anatomical behavior of their celiac artery and its branches, including its distribution areas, considering the importance of these vessels in the blood supply of several digestive organs.(AU)