Impairment of α1-adrenoceptor-mediated calcium influx in contralateral carotids following balloon injury: beneficial effect of superoxide anions.

There are many evidences indicating a compensatory mechanism in contralateral carotids following balloon injury. Previously it was observed α1-adrenoceptor-mediated hyper-reactivity and impairment of calcium influx in contralateral carotids 4 days after injury. At a later stage, α1-adrenoceptor-mediated contraction is similar to the control and we hypothesized that downstream signaling was normal. In the present study, we aimed to evaluate α1-adrenoceptor-mediated calcium influx in contralateral carotids 15 days after balloon injury. Concentration-response curves for CaCl2 in presence of the α1-adrenoceptor agonist (phenylephrine), measurement of the intracellular calcium transient and the levels of reactive oxygen species using fluorescent dyes were performed in control and contralateral carotids. Phenylephrine-induced intracellular calcium mobilization in contralateral carotids was not altered, while phenylephrine-induced calcium influx was reduced in the contralateral artery. Nitric oxide synthase inhibitors, L-NAME or L-NNA, restored this response, but nitrite and nitrate levels were decreased in contralateral carotids. Additionally, a rise in oxygen free radicals was observed in contralateral carotids. Furthermore, Tiron, a superoxide anion scavenger, restored α1-adrenoceptor-mediated calcium influx in contralateral carotids to the control level. Similar results were observed with the selective potassium channels blockers 4-aminopyridine and charybdotoxin. In conclusion, data showed that balloon catheter injury resulted in increased superoxide anions levels, activation of potassium channels (Kv and BKCa), inhibition of calcium channels (Cav) and preservation of α1-adrenoceptor-mediated contraction at a later stage after injury.

Hematopoiese extramedular decorrente de hemangiossarcoma em cão - Relato de caso / Extramedullary hematopoiesis arising from hemangiosarcoma in dogs

A hematopoiese extramedular (HE) é um mecanismo compensatório raro que surge em pacientes com distúrbios medulares graves para a correção do déficit de células sanguíneas no organismo, sendo uma de suas causas as anemais arregenerativas decorrentes de hemangiossarcoma. O objetivo dos pesquisadores é descrever um caos clínico de HE hepática decorrente de hemangiossarcoma em cão. Foi atendida no Hospital Veterinário da Universidade Federal Rural da Amazônia (HOVET/UFRA) uma cadela SRD, com oito anos de idade e peso vivo de 10 kg com histórico de êmese, anorexia, letargia, oligúria e presença de uma massa irregular de consistência firme no fígado. Dois meses antes, o animal já havia sido submetido à esplenectomia total devido a presença de hemangiossarcoma com peso de aproximadamente 3kg. A ultrassonografia evidenciou aumento das dimensões hepáticas, dilatação de vasos e dutos hepáticos, paredes espessadas, presença de duas áreas nodulares soltas na cavidade abdominal com aproximadamente quatro centímetros cranial a bexiga e ascite. O hemograma constatou anemia arregenerativa e leucocitose. Foi indicado tratamento sintomático, paracentese para drenagem do líquido cavitário sanguinolento, e laparotomia exploratória com transfusão sanguínea total. Foram administrados metoclopramida (1mg/kg IV), antibioticoterapia com metronidazol (25mg/kg BID) e ampicilina (25mg/kg BID) por via oral e fluido com solução de ringer com lactato acrescidos de vitaminas C e do complexo B. Durante a cirurgia foi identificada metástase em todos os órgãos abdominais e peritônio e optou-se pela realização da eutanásia. Durante a necropsia foi colhido material para exame histopatológico, tendo como resultado hemangiossarcoma e um achado relevante foi a presença de metaplasia mielóide hepática...

The extramedullary hematopoiesis (EH) is a compensatory mechanism that often arises in patients with severe marroudisorders for the correction of the deficit of blood cells in the body, one of the causes is nonregenerative anemia due to hemangiosarcoma. The researchers' objective is to describe a clinical case of EH in a dog's liver due to hemangiosarcoma. It was admitted at the Veterinary Hospital of the Federal Rural University of Amazonia (HOVET/UFRA) a 8 years old female, and weight 10kg, with history of vomit, anorexia, lethargy, oliguria, and presence of an irregular mass of firm consistency in the liver. Two months earlier, the animal had already been submitted to total splenectomy due the presence of hemangiosarcoma weighing about 3kg. Ultrasonography showed an increase in liver size, dilatation of vessels and hepatic ducts, thickened walls, presence of two nodular areas loose in the abdominal cavity with about four centimeters cranial to the bladder and ascites. The CBC noted not regenerative anemia and leukocytosis. It was indicated symptomatic treatment, paracentesis to drain the fluid cavity that was bloody, and exploratory laparotomy with total blood transfusion. Were administered metoclopramide (1 mg / kg BID) oral antibiotic therapy with metronidazole (25 mg/kg BID) and ampicillin (25 mg/kg BID) and fluid IV therapy with lactated ringer's solution plus vitamins C and B complex. During the surgery, it was detected metastasis in all abdominal organs and peritoneum and it was chosen to perform euthanasia. During the necropsy material was sampled for histopathological examination, resulting in hemangiosarcoma and one finding was the presence of hepatic myeloid metaplasia. The history of the patient with hemangiosarcoma, chronic bleeding and blood loss kidnapping and nutrition of the tumor led to severe and persistent anemia, which triggered a compensatory behavior forming sites of EH in liver...

Hematopoiese extramedular decorrente de hemangiossarcoma em cão - Relato de caso / Extramedullary hematopoiesis arising from hemangiosarcoma in dogs

A hematopoiese extramedular (HE) é um mecanismo compensatório raro que surge em pacientes com distúrbios medulares graves para a correção do déficit de células sanguíneas no organismo, sendo uma de suas causas as anemais arregenerativas decorrentes de hemangiossarcoma. O objetivo dos pesquisadores é descrever um caos clínico de HE hepática decorrente de hemangiossarcoma em cão. Foi atendida no Hospital Veterinário da Universidade Federal Rural da Amazônia (HOVET/UFRA) uma cadela SRD, com oito anos de idade e peso vivo de 10 kg com histórico de êmese, anorexia, letargia, oligúria e presença de uma massa irregular de consistência firme no fígado. Dois meses antes, o animal já havia sido submetido à esplenectomia total devido a presença de hemangiossarcoma com peso de aproximadamente 3kg. A ultrassonografia evidenciou aumento das dimensões hepáticas, dilatação de vasos e dutos hepáticos, paredes espessadas, presença de duas áreas nodulares soltas na cavidade abdominal com aproximadamente quatro centímetros cranial a bexiga e ascite. O hemograma constatou anemia arregenerativa e leucocitose. Foi indicado tratamento sintomático, paracentese para drenagem do líquido cavitário sanguinolento, e laparotomia exploratória com transfusão sanguínea total. Foram administrados metoclopramida (1mg/kg IV), antibioticoterapia com metronidazol (25mg/kg BID) e ampicilina (25mg/kg BID) por via oral e fluido com solução de ringer com lactato acrescidos de vitaminas C e do complexo B. Durante a cirurgia foi identificada metástase em todos os órgãos abdominais e peritônio e optou-se pela realização da eutanásia. Durante a necropsia foi colhido material para exame histopatológico, tendo como resultado hemangiossarcoma e um achado relevante foi a presença de metaplasia mielóide hepática... (AU)

The extramedullary hematopoiesis (EH) is a compensatory mechanism that often arises in patients with severe marroudisorders for the correction of the deficit of blood cells in the body, one of the causes is nonregenerative anemia due to hemangiosarcoma. The researchers' objective is to describe a clinical case of EH in a dog's liver due to hemangiosarcoma. It was admitted at the Veterinary Hospital of the Federal Rural University of Amazonia (HOVET/UFRA) a 8 years old female, and weight 10kg, with history of vomit, anorexia, lethargy, oliguria, and presence of an irregular mass of firm consistency in the liver. Two months earlier, the animal had already been submitted to total splenectomy due the presence of hemangiosarcoma weighing about 3kg. Ultrasonography showed an increase in liver size, dilatation of vessels and hepatic ducts, thickened walls, presence of two nodular areas loose in the abdominal cavity with about four centimeters cranial to the bladder and ascites. The CBC noted not regenerative anemia and leukocytosis. It was indicated symptomatic treatment, paracentesis to drain the fluid cavity that was bloody, and exploratory laparotomy with total blood transfusion. Were administered metoclopramide (1 mg / kg BID) oral antibiotic therapy with metronidazole (25 mg/kg BID) and ampicillin (25 mg/kg BID) and fluid IV therapy with lactated ringer's solution plus vitamins C and B complex. During the surgery, it was detected metastasis in all abdominal organs and peritoneum and it was chosen to perform euthanasia. During the necropsy material was sampled for histopathological examination, resulting in hemangiosarcoma and one finding was the presence of hepatic myeloid metaplasia. The history of the patient with hemangiosarcoma, chronic bleeding and blood loss kidnapping and nutrition of the tumor led to severe and persistent anemia, which triggered a compensatory behavior forming sites of EH in liver... (AU)