Lectin Histochemistry of Liver under the Conditions of Antihistamine Drugs Administration

Abstract

The objective of the research was to investigate the effect of long-term administration of antihistamine drug Loratadine on morpho-histochemical liver characteristics using lectins with different carbohydrate specificities.

Material and methods. Experiments were performed on 18 white male Wistar rats weighting 160-200 g. Experimental group animals once a day during 30 days were administered Loratadine orally in the form of an aqueous suspension at a dose of 0.15 mg/kg body weight. On 10th, 20th and 30th days after the last administration of drug animals were subjected to aether anesthesia and killed by cervical dislocation. Liver samples were fixed in 4% neutral formalin and embedded in paraffin. Carbohydrate determinants were detected with lectins Con A, LABA, SNA, WGA and SBA.

Results. Disorders of experimental animals’ liver microstructure were detected during the study of hematoxylin and eosin stained specimens. Disorders manifested in sinusoidal capillaries extension, hyperchromatism of cytoplasm and hepatocytes nuclei, hydropic degeneration, lymphoid infiltrations formation. SBA, WGA and Con А lectins appeared to be the most informative out of all used ones. In particular, normally SBA contoured sinusoidal endothelium, intensely reacted with perivascular tissue of portal tracts and of central veins. After Loratadine administration SBA binding to cytoplasmic glycoconjugates and hepatocytes nuclei significantly increased, while vascular endothelium reactivity became totally negated. Opposite redistribution nature was observed in WGA receptor sites: this lectin interacted with glycopolymers of cell membrane, cytoplasme and heterochromatin of hepatocytes nuclei in the liver of intact animals; after Loratadine administration reactivity of these structures reduced. Accumulation of small single cells between hepatocytes was the sign of hepatopathy. The cells showed intense reactivity with WGA lectin.

Conclusions. Prolonged use of Loratadine caused structural and histochemical changes in the liver that manifested in the sinusoidal capillaries expansion, formation of lymphoid infiltrates, redistribution and modification of carbohydrate epitopes of endothelium and hepatocytes, as well as the accumulation of strongly WGA-reactive cells between hepatocytes.