Oxidoreductases in early gestational monkey placenta during maternal malarial infection: histochemical localisation.

BACKGROUND & OBJECTIVES: Early gestational malaria is more deleterious than late gestational infection. Still the pathophysiology of maternofoetal organ--the placenta in malaria remains almost unexplored during early gestation. Present study dealing with oxidoreductases in early gestational placenta during maternal malarial infection of Plasmodium cynomolgi bastianellii in rhesus monkeys was anticipated to provide a better insight into the functional impairment of this organ leading to foetal abnormalities. METHODS: Three control and four experimental monkeys (Macaca mulatta) were quarantined for one month prior to experimentation. Experimental monkeys at 2- 2 1/2 months of gestation were inoculated with P. cynomolgi bastianellii. On attaining first peak of parasitaemia the placentae were collected from anesthetised animals. The snap-frozen, cryostat sections were subjected to histochemical localisation for 3 (or 17) beta-hydroxysteroid dehydrogenase (beta-HSD) [3 (or 17) beta-hydroxysteroid: NAD (P+) oxidoreductase, EC 1.1.1.51 hydroxysteroid dehydrogenases] and NADPH-tetrazolium reductase [NADPH: (acceptor) oxidoreductase, EC 1.6.99.1 NADPH-TR]. Comparative microscopy of control and malaria infected placental sections was performed and analysed. RESULTS: A localised decrease in both the enzymes was observed in syncytiotrophoblast layer of malaria infected monkey placenta. The areas showing morphological damage of syncytiotrophoblast were also depicting gross reduction in NADPH-TR activity. INTERPRETATION & CONCLUSION: The altered enzymatic activities [3 (or 17) beta-HSD and NADPH-TR] in malaria infected early gestational monkey placenta have been discussed in the light of placental function. It could be concluded by present studies that these alterations would affect the cellular metabolism especially steroidogenesis and detoxification process which in turn would affect the normal development of the foetus as well as maintenance of gestation.

Hydrolytic enzyme activity in rhesus monkey placenta during early gestational malaria: histochemical studies.

BACKGROUND & OBJECTIVES: Early gestational malaria is found to be more fatal than late gestational infection but the pathophysiology of early gestational placenta, the maternofoetal organ responsible for maintenance of pregnancy, remains unexplored. Present study dealing with hydrolytic enzymes in early gestational placenta of rhesus monkeys during Plasmodium cynomolgi infection was anticipated to provide a better insight into the functional impairment of this organ during early gestational maternal malaria. METHODS: Experimental monkeys (Macaca multtta) at 2-2 1/2 months of pregnancy were inoculated with P. cynomolgi bastianelli. After attaining first peak of parasitaemia the animals were anesthetised and placentae were collected for histochemical studies. The snap-frozen, cryostat sections were subjected to histochemical reactions for acid phosphatase and alkaline phosphatase. RESULTS: The placental syncytiotrophoblast showed a loss in alkaline phosphatase activity, while the trophoblast layers and phagocytic cells of the maternal blood showed increased acid phosphatase activity during early gestational malarial infection. Morphological damage to the placental tissue whenever occurred was associated with altered Alk pase activity. INTERPRETATION & CONCLUSION: The altered distribution of Ac pase and Alk pase in malaria infected early gestational placenta has been discussed in the light of placental function. It could be concluded by present studies that these malaria induced changes in hydrolytic enzyme activities in monkey placenta have a direct bearing on functional and morphological integrity of the placental tissue. These changes are apparently responsible for early gestational foetal death and abortions as reported in literature.

Alkaline phosphatase activity in plasma of pregnant chagasic patients

The Kinetic properties of plasma placental alkaline phosphatase patients with Chagas' disease were studied. When Cl2 Mg was used as activator the same increase of activity (17-20 per cent) was found in the chagasic and non chagasic groups. The enzyme was not inhibited by F-ion in any of the groups. No significant differences were detected between the two groups (chagasic and non chagasic) when the enzyme was treated with inhibitors such as EDTA and L-phenylamine. However, when the CN- ion was used, the enzyme of the normal pregnant women followed a Michaelian curve, whereas in the chagasic group a sigmoideal plot was observed. Thus, the Hill coefficient was 1.1 for the normal group and over 1.5 for the chagasic.

Hydrolytic enzymes of rhesus placenta during Plasmodium cynomolgi infection: ultrastructural and biochemical studies.

Placenta in monkey demonstrated altered pathophysiology after P cynomolgi infection. The electronmicroscopic observations showed slight complete focal necrosis of the placental tissue, besides alterations in total protein, phosphatases and proteinases. These changes in cellular constituents of placenta during malaria infection may be responsible for malfunctioning of the organ and in turn, abnormal development of foetus.