Anna Maria Bolognani Fantin

Histomorphological and cytochemical changes induced in the liver of goldfish Carassius carassius var. auratus by short-term exposure to lead

The cellular and molecular effects of experimental lead intoxication (5 mg l-1/24 h and 48 h) were studied in hepatocytes of Carassius carassius var. auratus. Significant lead storage was not detected by atomic absorbance spectroscopy after treatment. Cell morphology appeared only poorly impaired. A decrease of glycogen content was observed. Glycolysis, Krebs cycle and pentose shunt were altered in their enzymatic activities. Lysosomal activities were strongly increased. All enzymatic activities tested were altered 24 h after lead treatment.

Histochemistry of the glands associated with the reproductive tract of Lymnaea stagnalis

SummaryThe albumen gland, the muciparous gland and the oöthecal gland of female genital tract of Lymnaea stagnalis, collected in spring, autumn and winter have been studied.The reactions for polysaccharides, proteins and RNA have been performed in order to characterise the secretion of the glands.The albumen gland secretion consists almost exclusively of slightly acid polysaccharides whose histochemical reactions, according to Lison and Grainger and Shillitoe confirm the presence of galactogen. Proteins are also present in the secretion. The muciparous gland secretion consists of strongly acid mucopolysaccharides (non sulphated) produced by large cells among which small cells containing sulphated mucopolysaccharides are present.In the oöthecal gland two zones are present, one with a single type of cells containing acid mucopolysaccharides, and the other with two different types of cells: the first with mucopolysaccharides and the second with sulphated mucopolysaccharides, proteins and glycogen at the basis of the cell. Sialic acids are not present in the secretion of the glands studied.The polysaccharidic composition of the secretion of the glands is different from gland to gland. The secretion of the glands gradually changes and gets acid according to the composition of the various membranes and envelopes wrapping up the eggs.

Gill Endocrine Cells in the Goldfish Carassius carassius var. auratus and Their Impairment Following Experimental Lead Intoxication

The presence of endocrine cells in the gills of the goldfish Carassius carassius and the effects of lead intoxication (5 mg l−1) on their relative abundance and secretory activity were studied. Endocrine cells synthesizing peptido-like (met and leu-enkephalin and neuropeptide Y) and serotonin-like substances were detected in gill filaments by immunocytochemical procedures. Decreased immunoreactivity for two enkephalins and neuropeptide Y was observed after 48 and 96 h lead exposure. In contrast, increased serotonin immunoreactivity was evident after a one-week treatment. A search for Ca++-binding proteins was also carried out by immunocytochemical methods. Calbindin D-28K and S-100-like molecules were detected in gill epithelium, and their expression appeared enhanced after lead exposure.

Muramic acid as a glycoconjugate component in Mollusca Gastropoda

1. 1. Sialic acid is widely distributed in glycoconjugates in vertebrates (sialoglycoproteins and sialoglycolipids). 2. 2. The lack of sialic acid as glycoconjugate in Mollusca Gastropoda led us to investigate if it might be replaced by a similar C9 acidic glycoconjugate. 3. 3. The presence of muramic acid in Mollusca Gastropoda suggests that it might substitute sialic acid, at least in muramyl-glycoproteins in this group.

Enzymatic characterization of E.U.E. (embryonal human explants) cells adapted to hypertonic media.

E.U.E. cells (general population) were submitted to biochemical and cytoenzymatic tests to compare the enzymatic profile of E.U.E. cells (controls) with that of E.U.E. adapted to hypertonic medium. The adapted cells are characterized by very high oxoreductase activity (LDH, HBDH, G-6-P DH) and very high alkaline-phosphatase activity. Clones derived from general population were also submitted to biochemical tests to characterize those more strictly related to the enzymatic profile of adapted cells. The profile of clone N. 13 resembles on this respect that of the adapted cells. The high redox activity is a prerequisite supporting energy supply for osmotic work. The increased activity of plasma membrane enzymes of the adapted cells is also demonstrable in cells exposed for short time to salinity.

Effects of acute experimental pollution by lead on some haematological parameters in Carassius carassius (L.) var. auratus

Abstract Several haematological (RBC, WBC and thrombocyte count, HGB, HCT, MCV, MCH, MCHC) and serological parameters (lead blood content, ALA‐D, glucose, GOT, GPT, Try, Chol, TP, Na+, K+, Cl‐, Ca++) have been assayed in specimens of Carassius carassius (L.) var. auratus submitted to sublethal acute exposure to lead (5 ppm., 24 and 48 hrs). The following differences were observed between control and treated samples: the number of RBC was decreased after 48 hrs of treatment; haematocrit, haemoglobin percentage and MCHC were also decreased. Glucose and lead concentrations in blood were increased, whereas ALA‐D, transa‐minases and calcium were decreased. No significant variations in the other studied parameters were observed.

Gill morphology and ATPase activity in the goldfish Carassius carassius var. auratus exposed to experimental lead intoxication

Abstract The effect of acute lead intoxication (5 mg 1‐1) on the structure and function of the gills in Carassius carassius var. auratus was studied. The gills absorbed Pb very quickly and the storage increased progressively in the longest treated specimens. Light and electron microscopy observations on gill filaments from unexposed fish showed an organization similar to that described for other teleosteans. Gill histological and cytological alterations induced by lead were detected after 24 h of treatment and became more evident after 48 h. The salient changes were the following: 1) free parts of secondary lamellae increased in length and had irregular outlines; 2) an increased number of mucocytes, prevalently distributed over the superficial layer of the primary epithelium; 3) chloride and epithelial cell ultrastructure were particularly damaged; the degenerating chloride cells were more numerous; 4) K+‐NPPase activity was not particularly affected; on the contrary, Ca2+‐ATPase increased particularly in...

A histoenzymatic investigation of galactogen synthesis in the albumen gland of Helix pomatia and Lymnaea stagnalis.

SummaryA histoenzymatic investigation of Galaotogen synthesis has been attempted in the albumen gland of Helix pomatia and Lymnaea stagnalis. Using histoenzymatic methods the authors succeeded in finding only two enzymes (E.C. 2.7.7.9.=uridylyltransferase and E. C. 5.1.3.2.=epimerase) demonstrated by biochemical assays and isolated. They therefore assume that there may be other metabolic pathways in addition to those demonstrated by biochemical methods.

Biochemical and histochemical features of human cultured cells (EUE) adapted to hypertonic medium

EUE cells from a human heteroploid line cultured in hypertonic medium (0.274 M NaCl) modify their lipid pattern: sulfolipid concentration reaches 86 to 90 microgram/mg protein whilst it ranges between 19 to 32 microgram/mg in cells cultured in isotonic medium. Ganglioside concentration reaches 2.6 nmoles of sialic acid/mg protein (after 75 days) and 13 (after 85 days) in hypertonic saline medium. Whilst it is 0.5 in isotonic medium. Phospholipid concentration does not show any similar change. Cytoenzymatic analysis reveals that dehydrogenases (lactate, G-6-P dehydrogenases, tetrahydrofolate reductase and NADH diaphorase) appear strongly enhanced in cells grown on hypertonic medium. On the contrary higher acid phosphatase and ATPase activity was demonstrable in cells grown on isotonic medium. These results are similar (except for ATPase activity) to those observed in salt secreting glands involved in strong osmotic work. The results are discussed in relation to the problem of energy supply in cells performing osmotic work.

Ultrastructural changes in the ganglia of Viviparus ater following experimental lead intoxication

Abstract Ultrastructural damage in the ganglia of Viviparus ater specimens exposed to short-term static pollution by lead (1, 2, 5, and 10 mg/liter for 24, 48, and 96 hr) was studied. In polluted samples the neurons inside the ganglia are not regularly arranged in layers in the superficial zone of the ganglia but are irregularly scattered. Neuron structure appears particularly affected by lead exposure: the cell swells and the axon hillock is poorly distinguishable; the nucleus also frequently swells and the chromatin appears particularly dispersed; Nissl bodies appear disassembled and the ribosomes are not generally linked to the vesicle membranes; the mitochondria are also swollen, cristae practically disappear, and the matrix becomes homogeneous and electron transparent; and a noticeable increase in the number and size of secondary lysosomes was observed.