Da biópsia para o microscópio: processamento tecidual em odontologia

Objetivo: O objetivo desta revisão de literatura é descrever as etapas fundamentais do processamento tecidual para microscopia óptica com coloração de hematoxilina e eosina (HE) de interesse na odontologia. Revisão de Literatura: O processamento tecidual para coloração com HE é constituída basicamente por 7 etapas sequenciais. Imediatamente após a biópsia, o espécime é fixado em formol a fim de interromper a autólise tecidual. Em seguida, na etapa de clivagem, a peça sofre redução de tamanho para facilitar a penetração do agente fixador. Caso a amostra seja dente ou tecido ósseo, ela passa por um processo de descalcificação prévio à clivagem. Nas etapas de processamento e inclusão ocorre remoção de líquidos do interior das células para que em seu lugar entre parafina, e o tecido é incluido em um molde para formar um bloco rígido de parafina, o qual será cortado na fase de microtomia. Finas secções teciduais são então aderidas a uma lâmina, coloridas e seladas. Conclusão: Um ótimo resultado na obtenção de lâminas histológicas depende da execução correta de todas as etapas do processamento tecidual, sendo também influenciado pelos cuidados do cirurgião-dentista com a amostra a ser enviada ao laboratório.

Aim: The aim of this literature review is to describe the fundamental steps of tissue processing for optical microscopy with hematoxylin and eosin (HE) staining of interest in dentistry. Literature Review: Tissue processing for HE staining basically consists of 7 sequential steps. Immediately after the biopsy, the specimen is fixed in formaldehyde to stop tissue autolysis. Then, in the cleavage stage, it undergoes size reduction to facilitate the penetration of the fixing agent. If the sample is a tooth or bone tissue, it goes through a decalcification process prior to cleavage. In the processing and inclusion stages, liquids are removed from the interior of the cells so that paraffin enters in its place, and the tissue is included in a mold to form a rigid block of paraffin, which will be cut in the microtomy phase. Thin tissue sections are then adhered to a slide, colored and sealed. Conclusion: An excellent result in obtaining histological slides depends on the correct execution of all stages of the tissue processing, and is also influenced by the dentist's care with the sample to be sent to the laboratory.

Vitamin D3 mitigates type 2 diabetes induced by a high carbohydrate-high fat diet in rats: Role of the purinergic system.

This study evaluated the effect of vitamin D3 (VIT D3) supplementation on the enzymatic activities and density of ectonucleoside triphosphate diphosphohydrolase (E-NTPDase), ecto-5-nucleotidase (E-5'-NT), adenosine deaminase (ADA), as well as the density of P2 × 7R, P2Y12R, A1R, A2AR receptors, IL-1ß, and oxidative parameters in type 2 diabetic rats. Forty male Wistar rats were fed a high carbohydrate-high fat diet (HCHFD) and received an intraperitoneal injection containing a single dose of streptozotocin (STZ, 35 mg/kg). Animals were divided into four groups: 1) control; 2) control/VIT D3 12 µg/kg; 3) diabetic; and 4) diabetic/VIT D3 12 µg/kg. Results show that VIT D3 reduced blood glucose, ATP hydrolysis, ADA activity, P2Y12R density (platelets), as well as ATP, ADP, and AMP hydrolysis and ADA activity (synaptosomes). Moreover, VIT D3 increased insulin levels and AMP hydrolysis (platelets) and improved antioxidant defense. Therefore, we suggest that VIT D3 treatment modulates hyperglycemia-induced changes via purinergic enzymes and receptor expression, consequently attenuating insulin homeostasis dysregulation in the diabetic state.

Zinc and Manganese Imbalances in BALB/c Mice Experimentally Infected with Leishmania (Leishmania) amazonensis.

PURPOSE: The clinical progression of Leishmania (Leishmania) amazonensis infection depends on multiple factors, including immunological status of the host and their genotypic interaction. Several immunological processes depend directly on minerals for an efficient performance. Therefore, this study used an experimental model to investigate the alterations of trace metals in L. amazonensis infection associate with clinical outcome, parasite load, and histopathological lesions, and the effect of CD4 + T cells depletion on these parameters. METHODS: A total of 28 BALB/c mice were divided into 4 groups: 1-non-infected; 2-treated with anti-CD4 antibody; 3-infected with L. amazonensis; and 4-treated with anti-CD4 antibody and infected with L. amazonensis. After 24 weeks post-infection, levels of calcium (Ca), iron (Fe), magnesium (Mg), manganese (Mn), Cu, and Zn were determined by inductively coupled plasma optical emission spectroscopy using tissue samples of the spleen, liver, and kidneys. Additionally, parasite burdens were determined in the infected footpad (inoculation site) and samples of inguinal lymph node, spleen, liver, and kidneys were submitted to histopathological analysis. RESULTS: Despite no significant difference was observed between groups 3 and 4, L. amazonensis-infected mice had a significant reduction of Zn (65.68-68.32%) and Mn (65.98 to 82.17%) levels. Presence of L. amazonensis amastigotes was also detected in the inguinal lymph node, spleen, and liver samples in all infected animals. CONCLUSION: The results showed that significant alterations in micro-elements levels occur in BALB/c mice experimentally infected with L. amazonensis and may increase the susceptibility of individuals to the infection.

Bone cells and their role in physiological remodeling.

PURPOSE: This work compiles the characteristics of bone cells involved in the physiological bone remodeling. METHODS: A narrative review of the literature was performed. RESULTS: Remodeling is a different process from modeling. Remodeling allows old or damaged bone tissue to be renewed, ensuring the maintenance of bone fracture resistance, as well as maintaining calcium and phosphorus homeostasis. We present the role of osteoclasts, a multinucleated cell with hematopoietic origin responsible for resorbing bone. The formation of osteoclasts depends on the cytokines macrophage colony stimulating factor (M-CSF) and receptor activator of NF-kB ligand (RANKL) and can be blocked by osteoprotegerin. Furthermore, this review highlights the features of osteoblasts, polarized cubic cells of mesenchymal origin that deposit bone and also covers osteocytes and bone lining cells. This review presents the five fundamental phases of bone remodeling and addresses aspects of its regulation through hormones and growth factors. CONCLUSIONS: Knowledge of the current concepts of physiological bone remodeling is necessary for the study of the different pathologies that affect the bone tissue and thus helps in the search for new therapies.

In silico and in vivo protective effect of Morus nigra leaves on oxidative damage induced by iron overload.

Morus nigra L. is a plant popularly known as 'amoreira preta', very used in folk medicine. Iron overload (hemochromatosis) is a clinical condition that causes damage to various tissues due to oxidative stress. Therapy to control iron overload is still unsatisfactory. The protective effect on oxidative stress induced by iron overload was verified. Phytochemical characterization was evaluated by UHPLC-MS/MS. The in silico toxicity predictions of the main phytochemicals were performed via computer simulation. To induce iron overload, the animals received iron dextran (50 mg/kg/day). The test groups received doses of 500 and 1000 mg/kg of M. nigra extract for six weeks. Body weight, organosomatic index, serum iron, hepatic markers, cytokines, interfering factors in iron metabolism, enzymatic and histopathological evaluations were analyzed. Vanillic acid, caffeic acid, 6-hydroxycoumarin, p-coumaric acid, ferulic acid, rutin, quercitrin, resveratrol, apigenin and kaempferol were identified in the extract. In addition, in silico toxic predictions showed that the main compounds presented a low probability of toxic risk. The extract of M. nigra showed to control the mediators of inflammation and to reduce iron overload in several tissues. Our findings illustrate a novel therapeutic action of M. nigra leaves on hemochromatosis caused by iron overload.

Tucumã (Astrocaryum aculeatum) extract: phytochemical characterization, acute and subacute oral toxicity studies in Wistar rats.

Natural products are often used by the population to treat and/or prevent several disorders. Tucumã is an Amazonian fruit widely consumed by local population and no in vivo toxicity studies regarding its safety are available in the literature to date. Therefore, the phytochemical characterization, acute and repeated dose 28-day oral toxicities of crude extract of tucumã's pulp (CETP) in Wistar rats were evaluated. For the CETP preparation, tucumã pulp was crushed and placed into sealed amber glass jars containing absolute ethanol solution for extraction. CETP phytochemical analyses evidenced the presence of carotenoids, flavonoids, unsaturated and satured fatty acids, and triterpenes. In the acute toxicity, female rats from the test group were treated with CETP at single dose of 2000 mg/kg. For the repeated dose toxicity, CETP was administered to male and female rats at doses of 200, 400 and 600 mg/kg, for 28 days. Body weight was recorded during the experiment and blood, liver and kidney were collected for further analysis. No mortality or toxicity signs were observed during the studies. CETP was classified as safe (category 5, OECD guide), in acute toxicity. In repeated dose study was observed alterations in some biochemical parameters, as well as in oxidative damage and enzymatic activity. Histopathological findings showed renal damage in male rats at higher dose. The data obtained suggest that CETP did not induced toxicity after exposure to a single or repeated doses in female rats. However, in males may be considered safe when given repeatedly in low doses.

Preclinical safety assessment of the crude extract from Sida rhombifolia L. aerial parts in experimental models of acute and repeated-dose 28 days toxicity in rats.

Sida rhombifolia (Malvaceae) is popularly used as a treatment for several pathological conditions; however, there is a lack of studies that identify its compounds and that evaluate comprehensively the safety of its consumption. Therefore, the aim of this study was to determinate the phytochemical constitution of the crude extract of Sida rhombifolia (CESR), and its safety in models of acute and repeated doses (28 days) toxicity. The tested dose for the model of acute toxicity was 2000 mg/kg doses for the repeated dose model were 150, 300 e 600 mg/kg. Hematological, biochemical, histopathological and oxidative markers were investigated. HPLC-DAD-MS analysis evidenced the presence of caffeic acid, coumarin, and rutin. In the acute toxicity model the only altered parameters were tissue ROS, and AST and BUN in serum. As for the repeated dose experiment both hematological and biochemical markers remained within the values of reference for the species. Obtained results demonstrate that the CESR did not present significant toxic effects when administrated orally to male and female rats in acute and repeated doses.

Adjunctive antimicrobial photodynamic therapy using methylene blue/ethanol formulation in experimental periodontitis in diabetic rats: short-term results.

The aim of this study was to evaluate the effect of an MB experimental formulation (ethanol 20%) in aPDT used as an adjuvant to scaling and root planing (SRP) in the periodontal treatment of diabetic rats. Forty male Wistar rats received streptozotocin-intraperitonial injections to induce diabetes. After 14 days, 5 animals were allocated in the non-ligate group (NLG), and 35 animals received ligature at the first right mandibular molar to induce periodontitis. After 7 days, the ligature was removed and the animals were randomized into 4 groups: LG (without treatment, n = 5), SRPG (SRP, n = 10), aPDTW (SRP+aPDT-MB/water, n = 10), and aPDTEt (SRP + aPDT-MB/water/ethanol/carboxymethylcellulose, n = 10). Animals were euthanized after 7 days. Data of bone loss (BL) area, degree of inflammatory cell response, and collagen fibers percentages were statistically analyzed (p < 0.05). Percentage of animals that presented mild and severe inflammatory infiltrate was 10% and 40% for SRPG, 20% and 30% for aPDTW, and 50% and 0% for aPDTEt, respectively. BL area (mm2) was statistically higher in the LG (0.39 ± 0.15) than NLG (0.05 ± 0.02). aPDTEt showed the lowest value of BL (0.08 ± 0.03), followed by aPDTW (0.21 ± 0.15) and SRPG (0.31 ± 0.18). Statistical differences were verified between aPDTEt and SRPG. In relation to the LG, aPDTEt, aPDTW, and SRPG recovered the equivalent 80%, 46%, and 20% of the BL. aPDTEt showed collagen content statistically higher than SRPG and LG, and presented higher mean values than NLG (p > 0.05). Our findings showed aPDTEt presented promising results. aPDT using MB/ethanol can have potential as an adjunctive periodontal treatment in diabetics.

Reação liquenoide oral ao amálgama: uma lesão ainda vista / Oral lichenoid reaction to amalgam: a lesion still seen

O amálgama dental ainda é amplamente utilizado na prática odontológica, apesar do acordo assinado na Convenção de Minamata, na qual 140 países comprometeram-se a reduzir o uso do mercúrio. O uso desse material restaurador pode desencadear reações liquenoides orais (RLO) cujas lesões apresentam semelhanças clínicas e histológicas com líquen plano oral (LPO), dificultando o diagnóstico. Aqui relatamos o caso de uma paciente do sexo feminino, de 72 anos, que foi encaminhada com uma lesão na mucosa bucal esquerda, com 10 meses de evolução e queixa de dor. A lesão era adjacente ao segundo molar inferior esquerdo que tinha uma restauração de amálgama. A paciente não apresentava doença sistêmica ou hábitos deletérios e não estava usando drogas continuamente. O diagnóstico clínico presuntivo foi RLO versus LPO. Sessenta dias após a substituição da restauração do amálgama, observou-se a regressão completa da lesão e o diagnóstico final de RLO foi realizado. A avaliação clínica associada aos resultados obtidos após a substituição do material suspeito pode ser suficiente para estabelecer o diagnóstico, embora em alguns casos seja necessária a avaliação histopatológica.

Dental amalgam is still widely used in dental practice, despite the agreement signed at the Minamata Convention, in which 140 countries have committed to reducing the use of mercury. The use of this restorative material may trigger oral lichenoid reactions (OLR) whose lesions show clinical and histological similarities with oral lichen planus (OLP), making diagnosis difficult. Here we report the case of a female patient, 72-year-old, who was referred with a lesion in the left buccal mucosa, with 10 months of evolution and complaint of pain. The lesion was adjacent to the second lower left molar which had an amalgam restoration. The patient had no systemic disease or deleterious habits and was not using drugs continuously. The presumptive clinical diagnosis were OLR versus OLP. Sixty days after the replacement of amalgam restoration the complete regression of the lesion was observed and the final diagnosis of OLR was done. Clinical assessment associated with the results obtained after the replacement of suspect material may be sufficient to establish the diagnosis, although in some cases it may be necessary histopathological evaluation.

Antimicrobial photodynamic therapy with photosensitizer in ethanol improves oxidative status and gingival collagen in a short-term in periodontitis.

BACKGROUND: This study evaluated the antimicrobial photodynamic therapy (aPDT) effects using the methylene blue (MB) in ethanol 20% on systemic oxidative status and collagen content from gingiva of rats with periodontitis. METHODS: Rats were divided into five experimental groups: NC (negative control; no periodontitis); PC (positive control; periodontitis without any treatment); SRP (periodontitis and scaling and root planing), aPDT I (periodontitis and SRP+aPDT+MB solubilized in water), and aPDT II (periodontitis and SRP+aPDT+MB solubilized in ethanol 20%). After 7days of removal of the ligature, the periodontal treatments were performed. At 7/15/30days, gingival tissue was removed for morphometric analysis. The erythrocytes were used to evaluate systemic oxidative status. RESULTS: PC group showed higher lipoperoxidation levels at 7/15/30days. aPDT indicated a protective influence in erythrocytes at 15days observed by the elevation in levels of systemic antioxidant defense. aPDT II group was the only one that restored the total collagen area in 15days, and recovered the type I collagen area at the same time point. CONCLUSIONS: aPDT as an adjunct to the SRP can induce the systemic protective response against oxidative stress periodontitis-induced and recover the gingival collagen, thus promoting the healing periodontal, particularly when the MB is dissolved in ethanol 20%.

Role of acute phase proteins in the immune response of rabbits infected with Trypanosoma evansi.

The aim of this study was to characterize the response of acute phase proteins (APP) in rabbits experimentally infected with Trypanosoma evansi (T. evansi), and to relate the findings with serum immunoglobulins levels, in order to verify the relation between APP and the immune response of rabbits. A total of 12 animals were used in this experiment and divided into 2 groups, control and infected, of six rabbits each. The experimental period was 118 days, and blood was collected on days 0, 5, 20, 35, 65, 95 and 118 post-infection (PI). The infection with T. evansi stimulated APP and immunoglobulins production, once the infected animals showed an increase in C-reactive protein, haptoglobin, alpha 2-macroglobulin and IgM levels. The elevation in IgM levels observed in this study, when related to the increase in C-reactive protein and haptoglobin levels, suggests the involvement of these proteins in host defense against flagellated protozoa, with possible participation in the control of the parasitemia in rabbits infected with T. evansi.

Decanoato de nandrolona no hemograma e nas células mononucleares da medula óssea de ratos Wistar hígidos / Nandrolone decanoate in the hemogram and bone marrow mononuclear cells of healthy Wistar rats

O decanoato de nandrolona (DN), um estimulante do sistema hematopoético, caracteriza-se por ser um medicamento acessível aos proprietários de animais com escassos recursos econômicos. Assim, este estudo objetivou avaliar o efeito de diferentes doses do DN no hemograma e na quantificação e a viabilidade das células mononucleares (CM) da medula óssea (MO), juntamente com a marcação das células hematopoéticas CD34+ de ratos Wistar saudáveis. Para isso, 48 animais foram separados em seis tratamentos, de forma aleatória, com oito animais cada. Os grupos foram constituídos por: G1 - controle (solução fisiológica); G2 - controle diluente (somente veículo oleoso de origem vegetal); G3 - 0,42mg kg-1 de DN; G4 - 1,8mg kg-1 de DN; G5 - 4,6mg kg-1 de DN; e G6 - 10,0mg kg-1 de DN. O fármaco foi aplicado semanalmente por três semanas. Os parâmetros hematológicos e medulares avaliados não tiveram diferença significativa entre os grupos, o que pode ter sido influenciado pela condição da MO ou pelo intervalo entre as doses. De acordo com os resultados obtidos e nas condições em que esta pesquisa foi desenvolvida, pode-se concluir que o DN não altera o hemograma, a quantificação e a viabilidade das CM e a marcação de CD34+ em ratos wistar saudáveis.

Nandrolone Decanoate (ND), a hematopoietic system stimulant, is characterized as an accessible medicament for low-income pet owners. The aim of this research is to study the effect of different ND doses in the blood cytological parameters and the quantification and viability of the bone marrow (BM) mononuclear cells (MC), together with the labeling of CD34+ hematopoietic stem cells of healthy Wistar rats. Forty eight animals were randomly separated into six different groups of treatment, each composed of eight animals. These groups were divided in: G1 - control group (physiologic solution); G2 - diluent control (only vegetal oily vehicle); G3 - ND 0.42mg kg-1; G4 - ND 1.8mg kg-1; G5 - ND 4.6mg kg-1 and G6 - ND 10.0mg kg-1. The drug was weekly applied for three weeks. The hematologic and medullar analyzed parameters showed no significant difference between the groups, which may have been influenced by the BM conditions or by the applications frequency. According to the results obtained and according to the conditions under which this research was developed, it can be concluded that ND did not affect the blood cytological parameters, quantification and viability of MC and CD34+ labeling in healthy Wistar rats.

Hipoadrenocorticismo primário em um cão / Primary hipoadrenocorticism in a dog

O presente relato descreve um caso de hipoadrenocorticismo primário em uma fêmea canina, com seis anos de idade, sem raça definida, atendida no Hospital de Clínicas Veterinárias da Universidade Federal de Santa Maria. O cão apresentava letargia, vômito, anorexia, fraqueza, tremores, poliúria e polidipsia. Há um mês o animal estava sendo tratado para insuficiência renal crônica sem melhora clínica. Nos exames laboratoriais, evidenciaram-se anemia normocítica normocrômica, azotemia, hiponatremia, hipercalemia, hipercalcemia e hiperfosfatemia e, por meio de radiografia, foi observada microcardia. O diagnóstico foi confirmado pelas alterações eletrolíticas, principalmente por diminuição da relação sódio:potássio e pelo teste de estimulação com corticotrofina, que resultou em baixa concentração plasmática de cortisol pós-estimulação. Após o diagnóstico, iniciou-se terapia com acetato de fludrocortisona, com melhora significativa dos sinais clínicos depois de dois meses de tratamento.

This study describes a primary hypoadrenocorticism in a mixed-breed six years old bitch examined at the Federal University of Santa Maria Veterinary Hospital. The animal presented lethargy, vomiting, anorexia, weakness, shaking, polyuria and polydipsia. During a month the animal was medicated for chronic renal failure, showing no clinical progress. Laboratory exams evidenced a normocytic normochromic anemia, azotemia, hyponatremia, hyperkalemia, hypercalcemia and hyperphosphatemia. Microcardia was observed on radiographic exam. The diagnosis was confirmed by altered electrolytic pattern, mainly by sodium:potassium ratio and by corticotrophin stimulation test, which resulted in low plasma cortisol. After the diagnosis fludrocortisone acetate therapy has begun, showing a clinical evolution after two months treatment.

Perfil eletroforético das proteínas séricas de frangos de corte alimentados com dietas contendo aflatoxinas e/ou argila clinoptilolita natural / Electrophoresis profile of serum proteins in broilers fed with diets containing aflatoxins and/or natural clinoptilolite clay

O objetivo do presente trabalho foi avaliar o perfil eletroforético das proteínas séricas de frangos de corte alimentados com dietas contendo aflatoxinas e/ou argila clinoptilolita natural. Foram utilizados 528 frangos de corte, machos, da linhagem Ross, distribuídos em seis tratamentos com 4 repetições cada: T1 - testemunha (ração sem aflatoxinas ou clinoptilolita), T2 - ração com 5ppm de aflatoxinas, T3 - ração com 0,25 por cento de clinoptilolita, T4 - ração com 5ppm de aflatoxinas e 0,25 por cento de clinoptilolita, T5 - ração com 0,5 por cento de clinoptilolita e T6 - ração com 5ppm de aflatoxinas e 0,5 por cento de clinoptilolita. Os animais ficaram alojados em 24 boxes, e submetidos aos tratamentos do 1° ao 42° dia, quando foram sacrificados. Foram analisadas as proteínas totais, as frações albumina, alfa 1, alfa 2, beta e gama. Com exceção das médias da fração gama, o teste de Tukey revelou diferenças significativas (P<0,05) nas médias de todas as proteínas totais e frações protéicas nos tratamentos onde as aflatoxinas estavam presentes. A ação das aflatoxinas nas proteínas totais ocorre na síntese de albumina e globulinas (frações alfa e beta). As gamaglobulinas não são afetadas pelas aflatoxinas. Em relação ao controle, as aves alimentadas com dietas com aflatoxinas e clinoptilolita apresentaram baixos (P<0,05) níveis de proteína total, albumina e globulinas (alfa e beta). Conclui-se que as aflatoxinas alteram o perfil eletroforético e que a clinoptilolita adicionada na ração não é capaz de evitar essas alterações.

This study was aimed at evaluating the electrophoresis profile of serum protein in broilers fed with diets containing aflatoxins and natural clinoptilolite clay. Five hundred and twenty eight male broilers Ross were distributed in six treatments and each one with 4 replications: T1 - control (without aflatoxins or clinoptilolite), T2 -5ppm of aflatoxins, T3 -0.25 percent of clinoptilolite, T4 -5ppm of aflatoxins and 0.25 percent of clinoptilolite, T5 -0.5 percent of clinoptilolite and T6 - 5ppm of aflatoxins and 0.5 percent of clinoptilolite. The broilers were allocated in 24 boxes and submitted to a treatments for 42 days, when they were slaughtered. Total proteins, albumin fractions, alpha 1, alpha 2, beta and gamma were analyzed. Except gamma fraction the Tukey test showed differences (P<0.05) on serum total proteins and proteins fractions in all treatments which aflatoxin was present. The clinoptilolite did not modify (P<0.05) the serum proteins. The control broilers fed with diets containing aflatoxins and clinoptilolite presented low levels (P<0.05) of total protein, albumin, and globulins (alpha and beta fractions). In conclusion, aflatoxins change the electrophoresis profile and clinoptilolite is not able to protect avoid these changes.

Reticulócitos e hematócrito de cães pré e pós esplenectomia parcial / Reticulocytes and hematocrit of dogs before and after partial splenectomy

Os reticulócitos são células eritróides que exibem RNA residual e são liberados da medula óssea em resposta à hipoxia tecidual. Após sua liberação da medula óssea, ficam temporariamente seqüestrados no baço, onde adquirem forma de eritrócitos maturos. Além disso, o baço também é responsável pelo armazenamento do sangue e seus elementos. A esplenectomia é indicada para casos de torção ou ruptura esplênica, esplenomegalia sintomática e massas esplênicas. Este estudo tem como objetivo avaliar a resposta dos reticulócitos e do hematócrito em cães submetidos à remoção parcial do baço. Para isso, foram utilizados nove cães, sem raça definida, machos e fêmeas. As coletas foram feitas uma hora antes e 48, 96, 144 e 168 horas após o procedimento cirúrgico. Os resultados demonstraram que o hematócrito diminuiu significativamente após a esplenectomia parcial. O valor máximo de reticulócitos foi alcançado 96 horas após a cirurgia, a partir daí houve um declínio na quantidade de reticulócitos na corrente sangüínea, permanecendo, porém, em número superior à condição pré-esplenectomia parcial.

The reticulocytes are erythroid cells that exhibit residual RNA, being released from bone marrow by erythropoietin stimulus in response to tissue hypoxia. After its release from bone marrow, they are temporarily sequestred in the spleen, where they acquire form of mature erythrocytes. Besides, the spleen is also responsible for storage of the blood and their elements. The splenectomy is indicated in cases of splenic torsion or rupture, symptomatic splenomegaly, and splenic masses. This study aimed to evaluate the response of reticulocytes and of hematocrit in dogs submitted to partial splenectomy. Nine mongrel males and female dogs were used. The samples were obtained one hour before the surgery and 48, 96, 144 and 168 hours after this procedure. The findings demonstrated that the hematocrit decreases significantly after the partial splenectomy. Highest values reticulocytes were reached 96 h after the surgery, followed by a decline in number, nevertheless, the counting was higher than moments before of the partial splenectomy.