Haemopoietic System of the Anurans: The Role of Bone Marrow and Liver
The haemopoietic activity of the frog, Pelophylax ridibundus was investigated during the year. Liver and bone marrow myelograms were examined in the different seasons using the special indexes and coefficients. It was shown the presence of the erythroid and granulocytic differentiation during the year in the both organs. In the bone marrow is changing the total number of the non-diferentiated haemopoietic cells, but ratio between erythroid and granulocytic progenitors is stabile. The haemopoietic activity of the liver has more prominent season variation in comparison with the marrow, but their total significance is comparable. The erythrocytic differentiation is more prominent during the summer and autumn, but granulocytic one took place in the spring and summer.
Determination of the total biological effects of anthropogenic water pollution remains an important issue. Our long-term studies have shown that numerous alterations occur in the frog liver histological structure under pressure of anthropogenic pollution factor. Th e leukocyte infiltration, fat dystrophy, protein dystrophy and necrosis are well known on the mammal liver. Also we first described the rebuilding in the normal liver structure and the depletation of the fibrous tissue which are characteristic for the amphibians. Quantitative analysis of these alterations can identify significant differences in the pattern of pathological changes in the liver of the green frogs, which pick up in anthropogenically contaminated landscapes and in the clear ponds. Th is method allows quantifying the degree of biological effect of pollution.
The article describes characteristic features of the hematopoiesis in mature and immature green frogs (Pelophylax esculentus complex). Quantitative differences in liver myelograms were insignificant. However, in a sample of mature animals numerous significant correlations between the number of pigment inclusions in the liver and indicators of erythropoiesis and myelopoiesis were observed. Those correlations were absent in the immature frogs. We concluded that aft er the frogs’ breeding a lack of plastic resources, in particular, hemosiderin remains up to the hibernation.
In the article the histological changes in the liver of the common toad, Bufo bufo (Linnaeus, 1758), under conditions of moderate anthropogenic pollution (a vast park surrounded by urban areas) are examined. In the liver parenchyma, numerous changes characteristic of toxic damage were found: hepatocyte necrosis, fatty dystrophy, protein (and hydropic) dystrophy, signs of infl ammation. An analysis of the number of pigment inclusions in the liver shows hyperpigmentation in some specimens and hypopigmentation in others. The presence of hyperpigmentation indicates a moderate degree of damage and activation of compensation processes in animals. This is confirmed by a large population of common toads in this biotope. It is concluded that in anthropogenically modified biotopes some deterioration of animal health can be compensated by the absence of predators and the reduction of food competition.