Qualitative and quantitative ultrastructural analysis of the mitochondria from adrenal gland cortex under the action of viperidae family snake venoms / Análisis ultrastructural cualitativo y cuantitativo de la mitocondria de la glándula adrenal bajo la acción de los venenos de serpientes de la familia viperidae

SUMMARY: The Viperidae venoms are composed of a mixture of constituents with enzymatic and non-enzymatic actions, which act on ultrastructural components of cells and tissues. Here, the number of mitochondria, mitochondrial area and the number of mitochondrial cristae from adrenal glands cortex treated with snake venoms were tested after 3, 6 and 24 hours of venom injections. The mitochondria quantitative changes showed a statistically significant decrease, in the number of mitochondria past 3, 6 and 24 h. There was an increase in the mitochondrial area after 6 h, where Crotalus vegrandis venom did not present significant differences with Crotalus pifanorum or Bothrops venezuelensis venoms. After 24 h, there was an escalation of mitochondrial area in all tested venoms. The number of mitochondrial cristae after 3 h did not present important differences with the control treatment. After 6 h, the number of mitochondrial cristae initiated to decrease under the activities of the 3 venoms action, until 24 h of observation. In the qualitative observations it was possible to witness an intense damage of the mitochondria, with loss and swelling of membranes, disappearance of cristae and the appearance of myelin figures, which started at 3 h after the Crotalus and Bothrops venoms injections. These damages probably were due to cytotoxic effects of phospholipases, metalloproteases and/or other proteolytic activities present in Viperidae snake venoms, being more evident in Crotalus venoms. As far as we know, these results define a novel finding that suggest that Viperidae snake venoms are extremely toxic to mammalian mitochondria.

RESUMEN: Los venenos de Viperidae tienen acciones enzimáticas y no enzimáticas, que actúan sobre la estructura celular. Aquí se probaron, a las 3, 6 y 24 horas de la inyección del veneno, el número de mitocondrias, el área mitocondrial y el número de crestas mitocondriales de la corteza de las glándulas adrenales. Los cambios cuantitativos de las mitocondrias mostraron una disminución en el número de mitocondrias a las 3, 6 y 24 h. Hubo un aumento en el área mitocondrial a las 6 h, donde el veneno de la serpiente Crotalus vegrandis no presentó diferencias significativas con los venenos de Crotalus pifanorum o Bothrops venezuelensis. Después de 24 h, hubo un aumento del área mitocondrial en todos los venenos. El número de crestas mitocondriales a las 3 h no presentó alteraciones o diferencias importantes con el tratamiento de control. Después de 6 h, el número de crestas mitocondriales comenzó a disminuir bajo la acción de los 3 venenos, hasta las 24 h de observación. En las observaciones cualitativas se observó un daño intenso de las mitocondrias, con pérdida y edema de las membranas, desaparición de las cristae y aparición de figuras mielínicas, que comenzó a las 3 h después de las inyecciones de veneno de Crotalus y Bothrops. Estos daños se debieron factiblemente a los efectos citotóxicos de componentes proteolíticos de los venenos. Creemos que estos resultados definen un nuevo y original hallazgo, que sugiere que los venenos de serpiente Viperidae son extremadamente tóxicos para las mitocondrias de mamíferos.

Circadian pattern of Bothrops moojeni in captivity (Serpentes: Viperidae)

Members of the subfamily Crotalinae are considered to be essentially nocturnal and most of the data about these snakes have been collected from the field. Information on how nutritional status affects the movement rate and activity patterns is a key point to elucidating the ecophysiology of snakes. In this study, we distributed 28 lancehead Bothrops moojeni into three groups under distinct feeding regimens after a month of fasting. Groups were divided as follows: ingestion of meals weighing (A) 40 percent, (B) 20 percent, or (C) 10 percent of the snake body mass. Groups were monitored for five days before and after food intake and the activity periods and movement rates were recorded. Our results show that B. moojeni is prevalently nocturnal, and the activity peak occurs in the first three hours of the scotophase. After feeding, a significant decrease in activity levels in groups A and B was detected. The current results corroborate previous field data that describe B. moojeni as a nocturnal species with low movement rates. The relationship between motion and the amount of food consumed by the snake may be associated with its hunting strategy.

On a Haemogregarine sp. [protozoa, apicomplexa, adeleina] naturally infecting the viper Bitis arientans in Saudi Arabia with reference to the host-parasite relationship

The study described the developmental stages of a haemogregarine species in the blood and tissues of the viper Bitis arientans. Two out of 9 [22.2%] snakes from the south western region of Saudi Arabia, and recorded for the first time in such locality. The erythrocytic parasites were differentiated into three forms: the youngest form [trophozoite] measuring 7.34 +/- 0.16 x 3.38 +/- 0.07 micro m; the intermediate form [developing gametocyte] measuring 13.36 +/- 0.20 x 5.11 +/- 0.11 micro m and the largest form [mature gametocyte] measuring 18.69 +/- 0.32 x 4.32 +/- 0.16 micro m. None of the leucocytes seemed to be parasitized. Also, two types of meronts were detected in lung endothelial cells of infected vipers. Small meronts [micromeronts] measured 21.86 +/- 0.28 x 16.13 +/- 0.25 micro m and yielded about 12 merozoites. The large meronts [macromeronts] measured 38.09 +/- 0.33 x 21.52 +/- 0.32 micro m and yielded 28-42 merozoites. Random distribution of nuclei was observed in early meronts of both sizes, meanwhile peripheral arrangement of nuclei characterizing the subsequent developing events of meronts [ectomerogony]. Histopatho-logical studies showed that the infected erythrocytes were hypertrophied, mechanically stretched and their cytoplasm was faintly stained due to dehaemoglobinization. The host cell nucleus was elongated and laterally displaced. Trabeculae of the infected lung exhibited marked thickening and alveoli were collapsed in various degrees. Haemorrhagic foci and spongy structures were detected in some infected lung tissues. Formation of fibrous tissues around the meronts was seen in some foci