Influence of cytomegalovirus infection on nucleoside diphosphatase activity in placenta

Introduction. Cytomegalovirus infection (CMVI) makes a significant contribution to the development of pregnancy pathologies, including dysfunction of the placenta. However, the mechanism of such an effect of CMV has not been precisely established. For the coordination of biochemical reactions in the placenta, an optimal concentration of substances, including nucleotides, is required. Nucleoside diphosphatase is an enzyme that catalyzes the hydrolysis of nucleotide diphosphates to nucleotide and phosphate.Aim. Determination of the activity of nucleoside diphosphatase in the placenta in physiological and complicated CMVI reactivation in the third trimester of pregnancy.Materials and methods. A study of 62 placentas obtained during childbirth at 38-40 weeks was carried out. The first group consisted of the placentas from women with CMVI reactivation in the third trimester of pregnancy and the second – the placenta of women without a history of infectious pathology. Diagnosis of CMVI was carried out by determining antibodies of class M and G by ELISA, as well as CMV DNA was detected by PCR. Histochemical analysis of nucleoside diphosphatase was performed according to the method of A.B.Novikoff and D.S.Goldfischer modified by Z.Lojda et al.Results. In the second group, the placenta nucleoside-diphosphatase had a pronounced activity in the syncytiotrophoblast and the connective tissue stroma of the villi. When CMVI was reactivated in the third trimester of pregnancy, a decrease in the intensity of the histochemical reaction to nucleoside-diphosphatase was found: the cytophotometric index in the first group significantly (p<0.001) decreased to 13.06±0.089 rel. units (in the second group it was 14.11±0.119 relative units).Conclusion. The decrease in the activity of nucleoside diphosphatase found during the reactivation of CMVI in the third trimester of pregnancy might indicate a decrease in nucleotide metabolism in the placenta. In our opinion, the study of enzymes involved in the exchange of nucleotides will help to reveal the mechanisms by which CMV causes disturbances in the functioning of the placenta, leading to the development of complications of pregnancy.

Nucleoside-diphosphatase of cestode Bothriocephalus scorpii (Cestoda: Bothriocephalidae)

Objective of research: To study the activities and properties of nucleoside- diphosphatase (NDPase) in cestode Bothriocephalus scorpii. Materials and methods: Cestodes were homogenized with 10 vol. of extraction medium. NDPase was detected in mitochondria and microsomes with substrates (IDP, GDP, UDP). Inorganic phosphorus was determined by the method of Kochetov (1980). The effects of 10 anthelmintic drugs on the activity of NDPase were studied. Results and discussion: It was found that the mitochondrial and microsomal fractions of cestodes B. scorpii have nucleoside diphosphatase activity. The activity of nucleoside diphosphatase depends on substrates and Mg2+ ions. The impact of various effectors and ions (Ca2+, Mn2+, Zn2+) on enzyme activity was determined. Effects of 10 anthelmintic drugs on activity of nucleoside diphosphatase were studied. The anthelmintics Bitionol and Trichlorophen have been proved effective.

Biochemical characterization of Arabidopsis APYRASE family reveals their roles in regulating endomembrane NDP/NMP homoeostasis

The seven apyrase enzymes from Arabidopsis localize to the plant endomembrane. Our analyses indicate that five members (AtAPY1, 2, 4, 5 and 6) exhibit lumenal NDPase (nucleoside diphosphatase) activities whereas AtAPY3 has NTPase (nucleoside triphosphatase) activity. AtAPY7 displayed no nucleoside triphosphate diphosphohydrolases (NTPDase) activity.