Milk fatty acid profile from grazing buffaloes fed a blend of soybean and linseed oils / Perfil de ácidos graxos do leite de búfalas a pasto recebendo uma mistura de óleo de soja e linhaça na dieta

The aim of the study was to examine the changes in milk fatty acid (FA) profile of grazing buffaloes fed either low (L, 276g/d) or high (H, 572g/d) doses of a blend (70:30, wt/wt) of soybean and linseed oils. Fourteen multiparous Mediterranean buffaloes grazing on a native pasture were fed 4 kg/day of a commercial concentrate containing no supplemental oil over a pre-experimental period of ten days. The baseline milk production and composition and milk FA profile were measured over the last three days. After this pre-experimental period the animals received the same concentrate added with either the L or H oil doses for 26 additional days. Milk yield (g/animal/day) did not differ at the start (1776 ± 522 and 1662 ± 291 for L and H, respectively, P<0.622) or at the end of the trial (4590 ± 991 and 4847 ± 447 in L and H, respectively, P<0.543). Baseline milk fat content (g/kg) averaged 77.1 (±20.5) in L and 74.3 (±9.9) in H (P<0.10) and was reduced (P<0.031) to 60.7 (±23.6) and 49.4 (±11.2) (P<0.0031) respectively after L and H with no differences between treatments (P<0.277). Baseline milk protein content (L=43.2 ± 3.4 and H= 44.3 ± 6.9g/kg) increased after oil supplementation (P<0.0001) in both L (73.2 ± 6.0g/kg) and H (68.4 ± 4.9g/kg) without differences between oil doses (P<0.123). Milk fat content of 14:0 decreased after oil supplementation only in the H treatment (5.29 to 4.03, P<0.007) whereas that of 16:0 was reduced (P<0.001) at both L (24.49 to 19.75g/100g FA) and H (25.92 to 19.17g/100g FA) doses. The reduction of total content of 12:0 to 16:0 was higher (P<0.052) in H (32.02 to 23.93g/100g FA) than L (30.17 to 25.45g/100g FA). Vaccenic acid content increased (P<0.001) from 5.70 to 13.24g/100g FA in L and from 5.25 to 16.77 in H, with higher results in the in H treatment (P<0.001). Baseline rumenic acid was sharply increased (P<0.001) in L (1.80 to 4.09g/100g FA, +127%) and H (1.60 to 4.61g/100g FA, +187%) with no differences between...

O objetivo do presente estudo foi avaliar as mudanças no perfil de ácidos graxos do leite de búfalas leiteiras recebendo baixas (B, 276g/d) ou altas (A, 572g/d) doses de uma mistura de óleos de soja e linhaça (70:30, peso/peso) na dieta. Quatorze búfalas multíparas da raça Mediterrânea, mantidas em pastagens nativas, receberam 4kg/dia de um concentrado comercial sem adição de óleo (pré-tratamento) ao longo de umperíodopré-experimental de 10 dias. A produção de leiteindividual e amostras de leite foram coletadas individualmente para determinação dos valores basais de composição e perfil de ácidos graxos do leite nos últimos trêsdias. Após este período, os animais receberam o mesmo concentrado adicionado deBou Apor 26 dias. A produção de leite (g/animal/dia) não diferiu no início (1776 ± 522 e 1662 ± 291para B e A, respectivamente (P<0,622) e no final do período experimental(4590 ±991e4847 ± 447 para LeH, respectivamente, P<0,543). O teor de gordura do leite (g/100g) apresentou valores médios de 77,1(±20,5)paraBe74,3 (±9,9)paraA(P<0,10) durante o período pré-tratamento,mas foi reduzido (P<0,03) após o fornecimento das dietas com óleo para 60,7 (± 23,6) e 49,4 (± 11,2), respectivamente para B e A, não havendo diferenças entre tratamentos (P<0,277). Os teores basais de proteína do leite (B=43,2 ± 3,4 e A=44,3 ± 6,9g/kg) aumentaram após a suplementação com óleo (P<0,0001) em ambos B (73,2 ± 6,0g/kg) e A (68,4 ± 4,9g/kg), não ocorrendo diferenças entre tratamentos (P<0,123). O teor médio basal de 14:0 na gordura do leite (4,76g/100g AG) foi reduzido após a suplementação da dieta com óleo somente no tratamento A (5,29 para 4,03, P<0,007). O teor de 16:0 na gordura do leite foi reduzido (P<0,001) nos tratamentos B (24,49 para 19,75g/100g AG) e A (25,92 para 19,17g/100g AG). A redução nos teores de 12:0+14:0+16:0 na gordura do leite foi maior (P<0,052) em A (32,02 para 23,93g/100g AG) do que em B (30,17 para 25,45g/100g AG). O teor de ácido vacênico (AV)...

Decrease of intestinal tumors induced by 1,2-dimethylhydrazine in rats fed with cow milk and buffalo milk

Epidemiological studies in human beings and experimental studies in laboratory animals suggest that milk and dairy products can inhibit effects on the development of some kinds of tumors. Cow milk contains sphingomyelin, butyric acid, conjugated linoleic acid, calcium, vitamin A, carotene and vitamin D. All of these components are known to inhibit the process of carcinogenesis. Our objective was to determine the effect of cow milk and water buffalo milk on the development of colon neoplasias in an experimental model of carcinogenesis in rats induced with 1,2-dimethylhydrazine (DMH). Three-month-old Wistar male rats with an average body weight of 180 g were given a nutritionally adequate diet and drinking water adlivitum, cow milk or water buffalo milk. The milk diets were provided two weeks before the first DMH treatment and their administration was continued during the 10 weeks of DMH treatment. Milk administration finished two weeks after the last DMH doses treatment. Four months after the last carcinogen injection, all surviving animals were sacrificed and examined for intestinal tumors. The number, size, and location of the tumors were recorded and gross pathology was described. Small tumors (< 2.5 mm) were examined by Scanning Electron Microscopy (SEM). Significantly fewer tumors were observed in both groups treated with DMH and supplemented with milk, than in the group treated with DMH without milk administration.(AU)

Decrease of intestinal tumors induced by 1,2-dimethylhydrazine in rats fed with cow milk and buffalo milk

Epidemiological studies in human beings and experimental studies in laboratory animals suggest that milk and dairy products can inhibit effects on the development of some kinds of tumors. Cow milk contains sphingomyelin, butyric acid, conjugated linoleic acid, calcium, vitamin A, carotene and vitamin D. All of these components are known to inhibit the process of carcinogenesis. Our objective was to determine the effect of cow milk and water buffalo milk on the development of colon neoplasias in an experimental model of carcinogenesis in rats induced with 1,2-dimethylhydrazine (DMH). Three-month-old Wistar male rats with an average body weight of 180 g were given a nutritionally adequate diet and drinking water adlivitum, cow milk or water buffalo milk. The milk diets were provided two weeks before the first DMH treatment and their administration was continued during the 10 weeks of DMH treatment. Milk administration finished two weeks after the last DMH doses treatment. Four months after the last carcinogen injection, all surviving animals were sacrificed and examined for intestinal tumors. The number, size, and location of the tumors were recorded and gross pathology was described. Small tumors (< 2.5 mm) were examined by Scanning Electron Microscopy (SEM). Significantly fewer tumors were observed in both groups treated with DMH and supplemented with milk, than in the group treated with DMH without milk administration.

Effects of high molybdenum intake on 1.2 - dimethylhydrazine-induced intestinal tumors in rats

Wistar male rats, 3 months of age were given ad-libitum a nutritionally adequate diet and demineralized drinking water. The Molybdenum (Mo) and Tungsten (W) were provided in the drinking water at 200 ppm concentration. Intestinal tumors were induced by 1,2-dimethylhydrazine (DMH) given subcutaneously as 16 weekly doses at 20 mg/kg body weight. Mo in the form of (NH4)6 Mo7O24 4H2O or W in the form of (Na2WO4) were provided in the drinking water two months before the first DMH treatment and were continued during 4 months more until the last DMH treatment. Three months after the last carcinogen injection, all animals were sacrificed and examined for intestinal tumors. The number, size and location of the tumors were recorded and the pathology was examined. The addition of Mo to the drinking water induced an increase of hepatic Mo content. At the end of the second month, the hepatic content of Mo was 5.61 ppm, compared with control and W groups (2.18 and 0.96 ppm, respectively). A significantly lower incidence of tumors was observed in the Mo group (47), compared with the control group given DMH alone (105) and W group (113). On the other hand, the Mo group showed a significant decrease in the numbers of multiple tumors per rat. (AU)

Effects of high molybdenum intake on 1.2 - dimethylhydrazine-induced intestinal tumors in rats

Wistar male rats, 3 months of age were given ad-libitum a nutritionally adequate diet and demineralized drinking water. The Molybdenum (Mo) and Tungsten (W) were provided in the drinking water at 200 ppm concentration. Intestinal tumors were induced by 1,2-dimethylhydrazine (DMH) given subcutaneously as 16 weekly doses at 20 mg/kg body weight. Mo in the form of (NH4)6 Mo7O24 4H2O or W in the form of (Na2WO4) were provided in the drinking water two months before the first DMH treatment and were continued during 4 months more until the last DMH treatment. Three months after the last carcinogen injection, all animals were sacrificed and examined for intestinal tumors. The number, size and location of the tumors were recorded and the pathology was examined. The addition of Mo to the drinking water induced an increase of hepatic Mo content. At the end of the second month, the hepatic content of Mo was 5.61 ppm, compared with control and W groups (2.18 and 0.96 ppm, respectively). A significantly lower incidence of tumors was observed in the Mo group (47), compared with the control group given DMH alone (105) and W group (113). On the other hand, the Mo group showed a significant decrease in the numbers of multiple tumors per rat.

Effects of high molybdenum intake on 1,2-dimethylhydrazine-induced intestinal tumors in rats.

Wistar male rats, 3 months of age were given ad-libitum a nutritionally adequate diet and demineralized drinking water. The Molybdenum (Mo) and Tungsten (W) were provided in the drinking water at 200 ppm concentration. Intestinal tumors were induced by 1,2-dimethylhydrazine (DMH) given subcutaneously as 16 weekly doses at 20 mg/kg body weight. Mo in the form of (NH4)6 Mo7O24 4H2O or W in the form of (Na2WO4) were provided in the drinking water two months before the first DMH treatment and were continued during 4 months more until the last DMH treatment. Three months after the last carcinogen injection, all animals were sacrificed and examined for intestinal tumors. The number, size and location of the tumors were recorded and the pathology was examined. The addition of Mo to the drinking water induced an increase of hepatic Mo content. At the end of the second month, the hepatic content of Mo was 5.61 ppm, compared with control and W groups (2.18 and 0.96 ppm, respectively). A significantly lower incidence of tumors was observed in the Mo group (47), compared with the control group given DMH alone (105) and W group (113). On the other hand, the Mo group showed a significant decrease in the numbers of multiple tumors per rat.

Effects of high molybdenum intake on 1,2-dimethylhydrazine-induced intestinal tumors in rats.

Wistar male rats, 3 months of age were given ad-libitum a nutritionally adequate diet and demineralized drinking water. The Molybdenum (Mo) and Tungsten (W) were provided in the drinking water at 200 ppm concentration. Intestinal tumors were induced by 1,2-dimethylhydrazine (DMH) given subcutaneously as 16 weekly doses at 20 mg/kg body weight. Mo in the form of (NH4)6 Mo7O24 4H2O or W in the form of (Na2WO4) were provided in the drinking water two months before the first DMH treatment and were continued during 4 months more until the last DMH treatment. Three months after the last carcinogen injection, all animals were sacrificed and examined for intestinal tumors. The number, size and location of the tumors were recorded and the pathology was examined. The addition of Mo to the drinking water induced an increase of hepatic Mo content. At the end of the second month, the hepatic content of Mo was 5.61 ppm, compared with control and W groups (2.18 and 0.96 ppm, respectively). A significantly lower incidence of tumors was observed in the Mo group (47), compared with the control group given DMH alone (105) and W group (113). On the other hand, the Mo group showed a significant decrease in the numbers of multiple tumors per rat.

Muscular regeneration after myonecrosis induced by Bothrops jararacussu snake venom from Argentina.

Venom from Bothrops snake produces severe local symptoms on the envenomed victim, such as hemorrhage, edema and myonecrosis. The latter is perhaps the most important of all, since antivenom therapy is not effective for it, even when antivenom is injected only a few minutes after the accident. In this work, mice weighing 18-20 g (n = 5) were inoculated with 70 micrograms Bothrops jararacussu venom in 0.1 ml PBS in the gastrocnemius muscle. Mice were sacrificed using ether after 1, 12 hours, 3, 5, 7 days and 2, 3, 5, 6 weeks after the injection of the venom to obtain gastrocnemius muscles. They were fixed with Bouin's solution and stained using Hematoxylin--Eosin and Mason's trichromic stain was applied to visualize collagen fibers. Results showed that inflammatory reaction was evident after a few minutes of the venom injection, which was not evident after 6 weeks. Muscular fiber necrosis reached its highest level on the seventh day. Even thought regeneration of muscular fibers was important, they never reached the size of the control. We conclude that Bothrops jararacussu venom causes severe necrosis on muscle fibers with partial recovery, showing low hemorrhage and abundance of granulation tissue. This points that not all fibers were regenerated, which can be seen as a functional sequel for injured muscle.

Muscular regeneration after myonecrosis induced by Bothrops jararacussu snake venom from Argentina.

Venom from Bothrops snake produces severe local symptoms on the envenomed victim, such as hemorrhage, edema and myonecrosis. The latter is perhaps the most important of all, since antivenom therapy is not effective for it, even when antivenom is injected only a few minutes after the accident. In this work, mice weighing 18-20 g (n = 5) were inoculated with 70 micrograms Bothrops jararacussu venom in 0.1 ml PBS in the gastrocnemius muscle. Mice were sacrificed using ether after 1, 12 hours, 3, 5, 7 days and 2, 3, 5, 6 weeks after the injection of the venom to obtain gastrocnemius muscles. They were fixed with Bouins solution and stained using Hematoxylin--Eosin and Masons trichromic stain was applied to visualize collagen fibers. Results showed that inflammatory reaction was evident after a few minutes of the venom injection, which was not evident after 6 weeks. Muscular fiber necrosis reached its highest level on the seventh day. Even thought regeneration of muscular fibers was important, they never reached the size of the control. We conclude that Bothrops jararacussu venom causes severe necrosis on muscle fibers with partial recovery, showing low hemorrhage and abundance of granulation tissue. This points that not all fibers were regenerated, which can be seen as a functional sequel for injured muscle.

Histopathological characterization of nephritides in the brown capuchin monkey, Cebus apella (Primates: Cebidae).

The renal lesions are of special importance in the captive primates. The most commonly pathologies are: pyelonephritis, nephrocalcinosis, glomerulonephritis, congenital malformations, hydronephrosis and functional diseases. We report the histopathological study of renal lesions of five cases of deaths in Cebus apella (Primates) of the Argentinean Primate Center. The ages of the monkeys were from 4 months to 15 years old. Microscopically, we have observed principally acute diffuse proliferative glomerulonephritis, hilar mesangio proliferative glomerulonephritis, extracapilar glomerulonephritis with crescents, chronic interstitial nephritis and chronic pyelophritis.

Failure to induce tumors in the large intestine of Capuchin mokeys (Cebus apella) by using 1,2-dimethylhydrazine.

The purpose of this study was to produce tumors in the large intestine of Capuchin Monkeys (Cebus apella) by the administration of the colonotropic carcinogen 1,2-dimethylhydrazine (DMH). The subjects were 12 monkeys, all males, age 30 months, with a mean weight of 2.858 kg. The DMH was administered subcutaneously to six of the monkeys at a dosage of 25 mg/kg of body weight once a week for 16 weeks; control monkeys received an equivalent volume of the stock solution without DMH. Twenty months after administration of the first dose, the animals were sacrificed. None of the monkeys showed intestinal tumors. Samples of the gastrointestinal tract were removed, fixed, and stained according to standard histological techniques. Histological changes were seen in all of the DMH-treated animals; these consisted of glandular hyperplasia and hyperplasia of the epithelium overlying the lymphoid nodules. In addition, foci of dysplasia were found in three of the animals. Our results suggest that the DMH induced pre-neoplastic changes, characterized by hyperplasia and dysplasia, in the mucosa of the large intestine.

[Hemorrhagic, edema-forming, proteolytic and myonecrotic activities of viper venoms of Bothrops alternatus (Vibora de la Cruz)]. / Actividades hemorrágica, edematizante, proteolítica y mionecrótica de venenos de viboreznos de Bothrops alternatus (Víbora de la Cruz).

A study of hemorrhagic, edema-forming, proteolytic and myonecrotic activities induced by newborn Bothrops alternatus snake venoms from Argentina was performed. The analyzed venom had these activities with markedly differences when compared with the venom of adult specimens. Hemorrhagic activity was four times higher, while edema forming activity was ten times or more. But proteolytic activity was similar in both groups. Hystological analysis showed intense hemorrhage and muscular fiber myolisis after 60 minutes of venom injection. Myonecrosis and inflammatory exudate were higher in the following hours. Hemorrhage decreased after 24 hours and muscular fiber regeneration started after the first week with granulation tissue formation. On the fourth week regenerating muscular fiber areas and granulation tissue were still observed. As a conclusion, we can assume that the injury induced in the snake accident by newborn Bothrops alternatus snakes would be more intense than those induced by the adult ones.

[Toxic and enzymatic activities of the Bothrops moojeni venom from Argentina]. / Actividades tóxicas y enzimáticas del veneno de Bothrops moojeni de Argentina.

Toxic and enzymatic activity of Bothrops moojeni venom from Argentine. Hemorrhagic, edema forming, proteolytic and indirect hemolytic activities, myonecrosis and muscle regeneration using optic microscopy induced by Bothrops moojeni snake venom from Argentina were studied. The described activities were present in this venom. Myonecrosis was intense 60 minutes after venom injection, increasing its activity during the first 3 hours. Myolytic lesions rise above coagulative ones. Hemorrhage was minimum the same as the edema. After 3 hours polymorphonuclear inflammatory infiltrate was observed, with neutrophils. Macrophages were visible after 48 hours. After 3 days fibroblasts were present. At the 7 day muscle fiber regeneration were present, showing striations alternating with calcified areas. Bothrops moojeni venom injuries are intense and the recuperation of them can generate important tissue lose, with functional consequences.

Actividades hemorrágica, edematizante, proteolítica y mionecrótica de venenos de viboreznos de Bothrops alternatus (víbora de la Cruz) / Hemorrhagic, edema-forming, proteolytic and myonecrotic activities of viper venoms of Bothrops alternatus (Víbora de la Cruz)

Se realizó el estudio de las actividades hemorrágica, edematizante, proteolítica y mionecrótica inducida por veneno de viboreznos de Bothrops alternatus de Argentina. Los venenos estudiados poseen las actividades mensionadas, mostrando marcadas diferencias respecto al veneno de ejemplares adultos. Cuadriplica la capacidad hemorrágica, supera en más de diez veces la edematizante. La actividad proteolítica es la que menor diferencia posee. El análisis histológico mostró intensa hemorragia y miólisis de fibras musculares a los 60 minutos de exposición al veneno. La mionecrosis y el exudado inflamatório fueron más altos en las siguientes horas. La hemorragia disminuyó de 24 horas y la regeneración de las fibras musculares se inició en la primer semana con formación de tejido de granulación. A la cuarta semana se observaban áreas de regeneración de fibras musculares y aún se observada tejido de granulación. Se concluye que la injuria producida en los accidentes por viboreznos de Cothrops alternatus es más intensas que la inducida por ejemplares adultos de la misma especie. (AU)

Actividades tóxicas y enzimáticas del veneno de Bothrops moojeni de Argentina / Toxic and enzymatic activities of the Bothrops moojeni venom from Argentine

Se estudiaron las actividades hemorrágica, edematizante, proteolítica, hemolítica indirecta (in vitro) y por microscopía óptica la mionecrosis y regeneración de fibras musculares inducidas por veneno de Bothrops moojeni de Argentina. El veneno demostró poseer las actividades mensionadas. La actividad mionecrótica fue intensa a partir de los 60 minutos de exposición incrementando su intensidad a las 3 horas con predominio de lesiones de fibras musculares de tipo miolótico, respecto a necrosis coagulativa. En los cortes histológicos, la hemorragia fue mínima al igual que el edema, mientras que a las 3 horas se observó infiltrado inflamatorio polimorfonuclear con predominio de neutrófilos y a partir de las 48 horas se sumaron los macrófagos. Al tercer día se observaron fibroblastos, los que se incrementaron paulatinamente; a los 7 días se observó regeneración de algunas fibras musculares que presentaban estriaciones, a partir de la curta semana, éstas alternaban con áreas calcificadas. La recuperación de las lesiones fue parcial, con fibras musculares de menor diámetro que las normales, alterando con áreas de calcificación y otras de fibrosis. Las lesiones causadas por el veneno de Bothrops moojeni son intensas y por la recuperación parcial de las mismas, puede generar pérdida importante de tejidos, con secuelas funcionales. (AU)

Actividades hemorrágica, edematizante, proteolítica y mionecrótica de venenos de viboreznos de Bothrops alternatus (Víbora de la Cruz). / [Hemorrhagic, edema-forming, proteolytic and myonecrotic activities of viper venoms of Bothrops alternatus (Vibora de la Cruz)]

A study of hemorrhagic, edema-forming, proteolytic and myonecrotic activities induced by newborn Bothrops alternatus snake venoms from Argentina was performed. The analyzed venom had these activities with markedly differences when compared with the venom of adult specimens. Hemorrhagic activity was four times higher, while edema forming activity was ten times or more. But proteolytic activity was similar in both groups. Hystological analysis showed intense hemorrhage and muscular fiber myolisis after 60 minutes of venom injection. Myonecrosis and inflammatory exudate were higher in the following hours. Hemorrhage decreased after 24 hours and muscular fiber regeneration started after the first week with granulation tissue formation. On the fourth week regenerating muscular fiber areas and granulation tissue were still observed. As a conclusion, we can assume that the injury induced in the snake accident by newborn Bothrops alternatus snakes would be more intense than those induced by the adult ones.

Actividades tóxicas y enzimáticas del veneno de Bothrops moojeni de Argentina. / [Toxic and enzymatic activities of the Bothrops moojeni venom from Argentina]

Toxic and enzymatic activity of Bothrops moojeni venom from Argentine. Hemorrhagic, edema forming, proteolytic and indirect hemolytic activities, myonecrosis and muscle regeneration using optic microscopy induced by Bothrops moojeni snake venom from Argentina were studied. The described activities were present in this venom. Myonecrosis was intense 60 minutes after venom injection, increasing its activity during the first 3 hours. Myolytic lesions rise above coagulative ones. Hemorrhage was minimum the same as the edema. After 3 hours polymorphonuclear inflammatory infiltrate was observed, with neutrophils. Macrophages were visible after 48 hours. After 3 days fibroblasts were present. At the 7 day muscle fiber regeneration were present, showing striations alternating with calcified areas. Bothrops moojeni venom injuries are intense and the recuperation of them can generate important tissue lose, with functional consequences.

Actividades hemorrágica, edematizante, proteolítica y mionecrótica de venenos de viboreznos de Bothrops alternatus (víbora de la Cruz) / Hemorrhagic, edema-forming, proteolytic and myonecrotic activities of viper venoms of Bothrops alternatus (Víbora de la Cruz)

Se realizó el estudio de las actividades hemorrágica, edematizante, proteolítica y mionecrótica inducida por veneno de viboreznos de Bothrops alternatus de Argentina. Los venenos estudiados poseen las actividades mensionadas, mostrando marcadas diferencias respecto al veneno de ejemplares adultos. Cuadriplica la capacidad hemorrágica, supera en más de diez veces la edematizante. La actividad proteolítica es la que menor diferencia posee. El análisis histológico mostró intensa hemorragia y miólisis de fibras musculares a los 60 minutos de exposición al veneno. La mionecrosis y el exudado inflamatório fueron más altos en las siguientes horas. La hemorragia disminuyó de 24 horas y la regeneración de las fibras musculares se inició en la primer semana con formación de tejido de granulación. A la cuarta semana se observaban áreas de regeneración de fibras musculares y aún se observada tejido de granulación. Se concluye que la injuria producida en los accidentes por viboreznos de Cothrops alternatus es más intensas que la inducida por ejemplares adultos de la misma especie.

Actividades tóxicas y enzimáticas del veneno de Bothrops moojeni de Argentina / Toxic and enzymatic activities of the Bothrops moojeni venom from Argentine

Se estudiaron las actividades hemorrágica, edematizante, proteolítica, hemolítica indirecta (in vitro) y por microscopía óptica la mionecrosis y regeneración de fibras musculares inducidas por veneno de Bothrops moojeni de Argentina. El veneno demostró poseer las actividades mensionadas. La actividad mionecrótica fue intensa a partir de los 60 minutos de exposición incrementando su intensidad a las 3 horas con predominio de lesiones de fibras musculares de tipo miolótico, respecto a necrosis coagulativa. En los cortes histológicos, la hemorragia fue mínima al igual que el edema, mientras que a las 3 horas se observó infiltrado inflamatorio polimorfonuclear con predominio de neutrófilos y a partir de las 48 horas se sumaron los macrófagos. Al tercer día se observaron fibroblastos, los que se incrementaron paulatinamente; a los 7 días se observó regeneración de algunas fibras musculares que presentaban estriaciones, a partir de la curta semana, éstas alternaban con áreas calcificadas. La recuperación de las lesiones fue parcial, con fibras musculares de menor diámetro que las normales, alterando con áreas de calcificación y otras de fibrosis. Las lesiones causadas por el veneno de Bothrops moojeni son intensas y por la recuperación parcial de las mismas, puede generar pérdida importante de tejidos, con secuelas funcionales.

[Hemorrhagic and edema-forming activity and histologic changes in the mouse footpad induced by venoms from Argentinian Bothrops and Crotalus genuses]. / Actividades hemorrágica y edematizante y alteraciones histológicas en almohadilla plantar del ratón inducidas por venenos de serpientes de los géneros Bothrops y Crotalus de Argentina.

Hemorrhagic, oedema-forming activities and histopathological alterations in the mouse footpad induced by Bothrops and Crotalus snake venoms from Argentina. Hemorrhagic and oedema-forming activities of various Bothrops and Crotalus snake venoms from Argentina were studied, together with histological alterations in the mouse footpad. The highest oedema-forming activity was found in the venom of B. jararaca, followed by B. jararacussu, B. neuwiedii diporus, B. alternatus, and Crotalus durissus terrificus. Regarding hemorrhage, the highest activity was found in the venom of B. neuwiedii diporus, followed by B. jararacussu, B. alternatus, and B. jararaca. No hemorrhage was observed after injection of Crotalus durissus terrificus venom, in agreement with histological observations of injected footpads. Histological analysis revealed a conspicuous inflammatory reaction in the injected footpad, characterized by oedema and an inflammatory infiltrate rich in polymorphonuclear leucocytes. Necrotic blood vessels and dilated lymphatic vessels were observed after injection of B. jararaca and B. jararacussu venoms, and myonecrosis was evident in tissue of mice injected with B. alternatus and B. neuwiedii diporus.