The mechanisms and myocardial alterations associated with NO-deficient hypertension are still far from clear. The aim of the present study was to focus on the enzyme histochemical and subcellular changes in the heart of L-NAME treated rats, as well as to examine the influence of captopril treatment. Wistar rats were administered either L-NAME (40 mg/kg/day) alone or together with captopril (100 mg/kg/day) for a period of 4 weeks. A significant increase of blood pressure confirmed the reliability of the model. The results showed that long-lasting L-NAME administration was accompanied by a decrease of endothelial NO-synthase activity and by a significant local decrease of the following enzyme activities: capillary-related alkaline phosphatase, 5’-nucleotidase and ATPase (but not dipeptidyl peptidase IV) and cardiomyocyte-related glycogen phosphorylase, succinic dehydrogenase, ß-hydroxybutyrate dehydrogenase and ATPases. No activity of these enzymes was found in the scar, whereas a marked increase of alkaline phosphatase and dipeptidyl peptidase IV activities was found in the foci of fibrotization. Histochemical changes correlated with subcellular changes, which were characterized by 1) apparent fibroblast activation associated with interstitial/perivascular fibrosis, 2) heterogeneous population of the normal, hypertrophic and injured cardiomyocytes, 3) enhancement of the atrial granules and their translocation into the sarcolemma, and 4) impairment of capillaries as well as by induction of angiogenesis. Similar alterations were also found in the heart of captopril co-treated rats, despite of the significant suppression of blood pressure. The results indicate that NO-deficient hypertension is accompanied by metabolic disturbances and ultrastructural alterations of the heart and these changes are probably not induced by the renin-angiotensin system only., N. Tribulová, Ľ. Okruhlicová, I. Bernátová, O. Pecháňová., and Obsahuje bibliografii
Histochemical techniques were applied to whole mounts, to study the distribution of the enzymes alkaline phosphatase, acid phosphatase, adenosine triphosphatase, 5'-nucleotidase and glucose-6-phosphatase in the organs and tissues of a viviparous monogenean, Macrogyrodactylus clarii Gussev, 1961, from the gills of the North African catfish Clarias gariepinus (Burchell) in Egypt. The following organs and tissues were studied: head region, anterior adhesive glands, mouth region, pharynx, intestine, testis, vesicula seminalis, male accessory gland, male accessory reservoir, copulatory organ, receptaculum seminis, egg-cell forming region, embryonic cells, excretory system, nerve cells, haptor, muscle fibres and subtegumental cell bodies (cytons). The enzymes showed marked differences in their activities among the studied organs and tissues. Alkaline phosphatase and acid phosphatase activities were detected in many organs and tissues, while the activities of adenosine triphosphatase, 5'-nucleotidase and glucose-6-phosphatase were restricted to a few organs. Although no positive reaction for any enzyme was observed in the anterior adhesive gland cells, a positive reaction for acid phosphatase was detected in the anterior adhesive areas. All enzymes showed marked activity in the digestive and excretory systems. The distribution of the enzymes in the tissues and organs of M. clarii is compared with those of other monogeneans, including other gyrodactylids parasitizing the same host fish. Some possible functions of the enzymes are discussed.
The presence of terminal carbohydrate residues in Enteromyxum leei (Diamant, Lom et Dyková, 1994) Palenzuela, Redondo et Álvarez-Pellitero, 2002 stages in gilthead seabream intestines was studied at light microscopy (LM) and transmission electron microscopy (TEM) level using lectin histochemical techniques. Abundant mannose and/or glucose residues were demonstrated by the intense staining caused by binding of biotinylated concanavalin A (Con A), at both LM and TEM. A clear positivity was also obtained with Ulex europaeus (UEA I) agglutinin specific for fucose residues. Both lectins stained E. leei proliferative and sporogonic stages, though glycan patterns varied between these developmental stages. Wheat germ agglutinin (WGA) and Bandeiraea simplicifolia lectin I (BSL I) recognised only structures in the sporogonic stages. Faint labelling occurred with Glycine max (SBA) lectin. No staining was obtained with Sambucus nigra (SNA) agglutinin. The TEM studies demonstrated a restricted presence of N‑acetyl-D-galactosamine and α-D-galactose, whereas glucose/mannose and fucose, the dominant structures, were also present at the parasite membranes and host-parasite interface, suggesting a role in host-parasite interaction.