Physiological studies on the effects of nutritional imbalance on the central nervous system. II. Effects of thiamine deficiency on oxidative enzymes in the brain of chicken,Gallus domesticus

Summary The activity levels of succinate dehydrogenase, glutamate dehydrogenase and pyruvate dehydrogenase in the fore, mid and hind brain regions of the thiamine deficient chicken,Gallus domesticus were determined. The activity levels of scccinate dehydrogenase and glutamate dehydrogenase in all the 3 regions of brain showed augmentation on inducing thiamine deficiency. In contrast the activity levels of pyruvate dehydrogenase decreased in the brain of thiamine deficient animals. It is suggested that these changes in the oxidative enzymes indicate disturbance caused in the operation of the tricarboxylic acid cycle in thiamine deficiency.     

Rhythmic variations in the activities of aldolase and isocitrate dehydrogenase in the heart muscle of the scorpion,Heterometrus fulvipes (C. Koch)

Summary The activity levels of aldolase and isocitrate dehydrogenase were assayed in the heart muscle of scorpion,Heterometrus fulvipes. The enzyme activities showed a circadian rhythmicity with a peak value at 20.00 h in the heart muscle.     

Acetaldehyde oxidation inDrosophila null-mutants for alcohol dehydrogenase

Summary Aldehyde dehydrogenase (ALDH) activity is demonstrated in four strains ofD. melanogaster lacking active alcohol dehydrogenase (ADH-null mutants). In the four strains, ALDH activities are similar to those found in a wild strain. It is concluded that ADH-null flies are able to detoxify acetaldehyde. This finding is discussed in relation with the dual function of ADH proposed recently.This work was supported by a grant from the Medical Research Council of Canada (MRC 6920) to Dr F. Garcin.     

Photoregulation of some enzymes fromNeurospora crassa

Summary Light-grown cultures ofNeurospora crassa showed photoregulation of a number of enzymes. Proteases and cytosolic malate dehydrogenase showed an increase in activity. There was a decrease in the activity of mitochondrial malate dehydrogenase, isocitrate dehydrogenase and cytosolic glucose-6P-dehydrogenase, isocitrate dehydrogenase and isocitrate lyase.     

Effect of a sesquiterpene fromAristolochia indica Linn. on fertility in female mice

Summary A sesquiterpene isolated from the roots ofAristolochia indica (Linn.) was found to exert 100% interceptive activity and 91.7% anti-implantation activity in mice at a single oral dose of 100mg/kg b. wt. No toxic effect was found at the dose levels used.The authors wish to thank Dr S. C. Pakrashi and his associate Mr P. P. Ghosh Dastidar of Medicinal Chemistry Department for isolating the compound for this study. Thanks are also due to Director-General of Indian Council of Medical Research for granting a Junior Research Fellowship to C.S.     

Ethanol as a ‘food’ forDrosophila melanogaster: Influence of theEbony gene

Summary The survival time of adultDrosophila melanogaster flies without food is greater in the presence of ethanol, especially for flies of strains or lines with a higher alcohol dehydrogenase activity. It seems that theebony gene can act in some populations as a selective factor favoring the ADH^F allele, as well as the minor genes enhancing the alcohol dehydrogenase activity level.Chargé de Recherches au F. N. R. S.     

A new host species for lactic dehydrogenase virus

Summary Lactic dehydrogenase virus has been found to replicate and maintain a chronic infection in the Asian mouseMus caroli as it does inMus musculus. However, the level of viraemia is lower and the increase in plasma lactate dehydrogenase activity very much less.I thank Miss Maureen Bain for valuable technical assistance.     

Enzymes of arginine biosynthesis in methanogenic bacteria

Summary Methanobacterium thermoautotrophicum, Methanococcus vannielii andMethanobrevibacter arboriphilus, the 3 methanogenic bacteria tested, possessed an ornithine acetyltransferase and an arginine-sensitiveN-acetylglutamate 5-phopshtransferase. These 2 enzymes, as well as acetylornithinase and ornithine carbamoyltransferase, were insensitive to oxygen and were present at activity levels comparable to the levels observed in eubacteria.Acknowledgments. This work was supported by the Swiss National Foundation for Scientific Research (project No. 3.287.82). We thank A. Kiener for valuable discussions.     

Effect of the juvenoid methoprene on the hemolymph composition of the cabbage maggotDelia radicum (Diptera: Anthomyiidae)

Summary Treatment of post-feeding larvae of the cabbage maggotDelia radicum with methoprene did not affect the capacity of the insect to pupate, but suppressed eclosion to the adult stage. The concentration of hemolymph trehalose was significantly decreased by methoprene treatment, although hemolymph protein and amino nitrogen levels were unaffected.19 December 1986The authors are grateful to D. C. Read of the Research Centre, Agriculture Canada, Charlottetown, P.E.I., Canada for supplying eggs ofD. radicum for the stock colony. TheD. radicum colony was maintained at the Agriculture Canada Research Station, St. John's West, Newfoundland, Canada. The sample of methoprene was donated by Zoecon Corp., Palo Alto, California, U.S.A. This research was supported by a grant from the Natural Sciences and Engineering Research Council of Canada (Operating grant A6679).     

Pyridoxine application enhances nitrate reductase activity and productivity ofVigna radiata

Summary Pyridoxine, applied to seeds before sowing or by the spraying of a standing crop of moong (Vigna radiata) significantly enhanced leaf nitrate reductase activity (NRA). Leaf NRA levels, being significantly correlated with seed yield, can be utilized for predicting crop productivity and for adopting corrective measures, if necessary, at an early growth stage.Acknowledgment. This work was partly supported by the award of a Research Fellowship to S.A.A. by the Government of India Council of Scientific and Industrial Research, New Delhi, which is gratefully acknowledged.     

Trypsin activity in the hepatopancreas ofMacrobrachium lamarrei (Crustacea: Decapoda)

Summary Trypsin from the hepatopancreas ofMacrobrachium lamarrei showed optimum activity at pH 7.5 and temperature 45°C. The enzyme activity increased with the increase in incubation period and enzyme concentration. Michaelis constant of the enzyme was 2.38×10^–2 M.Acknowledgments. The authors are thankful to University Grants Commission, India for the award of a Junior Research Fellowship.     

Isozymes inDrosophila cell line

Summary Alcohol dehydrogenase, octanol dehydrogenase and fumarase isozyme patterns inDrosophila tissue culture cells were compared with the respective isozyme development pattern in the parental strain. The cell line lacks ADH activity and its fumarase isozyme pattern resembles the pupae and adult type.     

Physiological studies on the effects of nutritional imbalance on the central nervous system. II. Effects of thiamine deficiency on oxidative enzymes in the brain of chicken, Gallus domesticus.

The activitiy levels of succinate dehydrogenase, glutamate dehydrogenase and pyruvate dehydrogenase in the fore, mid and hind brain regions of the thiamine deficient chicken, Gallus domesticus were determined. The activity levels of succinate dehydrogenase and glutamate dehydrogenase in all the 3 regions of brain showed augmentation on inducing thiamine deficiency. In contrast the activity levels of pyruvate dehydrogenase decreased in the brain of thiamine deficient animals. It is suggested that these changes in the oxidative enzymes indicate disturbance caused in the operation of the tricarboxylic acid cycle in thiamine deficiency.     

Melezitase and maltase from the midgut ofSesamia inferens Walker (Lepidoptera: Insecta)

Summary The activity of melezitase and maltase was optimal at pH 6.2 and temperature 35–40°C and inhibited by the end-products. Melezitase activity was affected by K⁺, Li⁺⁺ andTris ions and was reduced by dialysis.Acknowledgments: The author is thankful to ProfessorR. Rakshpal for valuable guidance, and to University Grants Commission, for awarding me a Junior Research Fellowship.     

Aldose metabolism in developing human fetal brain and liver

Summary Aldose reductase, sorbitol dehydrogenase, and glucose-6-phosphate dehydrogenase enzyme activities were studied in human foetal brain and liver at different periods of gestation. Aldose reductase activity in liver disappears after 16 weeks of gestation whereas sorbitol dehydrogenase keeps on increasing in liver as well as in brain. In utero, some glucose metabolism may be mediated through an active sorbitol pathway in human fetuses.Acknowledgments. These studies were supported by the Indian Council of Medical Research.     

Effects of gonadotropin-releasing hormone (LH-RH) on the pars distalis and testis of the Skipper frog,rana cyanophlyctis (Schn.)

Summary Administration of LH-RH to adult male Skipper frogs resulted in marked hypertrophy and degranulation of basophils-2 (B2) in the pars distalis of the pituitary and a significant increase in their nuclear and cellular area. Concomitantly, there is a significant increase in the relative weight of the testes, in the number of cell nests containing secondary spermatogonia and primary spermatocytes, and in the nuclear diameter of the Leydig cells. There is also an increase in the ⁵-3-hydroxysteroid dehydrogenase and glucose-6-phosphate dehydrogenase activities in the Leydig cells. The results indicate that the B2 cells are gonadotrops and the hormone(s) secreted by B2 cells regulate the spermatogenetic and steroidogenic activity of the testis inR. cyanophlyctis.The free gift of LH-RH from NIH is gratefully acknowledged. Authors are grateful to CSIR, New Delhi, for the award of a SRF to the first author and to Karnatak University, Dharwad for providing laboratory facilities.     

Adrenal corticosteroidogenesis after removal of ventral prostate gland

Summary Removal of the ventral prostate gland in adult male rats causes an increase in adrenal weight, and stimulation of adrenal ⁵-3-hydroxysteroid dehydrogenase activity along with elevation of serum levels of corticosterone and prolactin.     

Enrichment of ligands with molecular dockings and subsequent characterization for human alcohol dehydrogenase 3

Alcohol dehydrogenase 3 (ADH3) has been assigned a role in nitric oxide homeostasis due to its function as an S-nitrosoglutathione reductase. As altered S-nitrosoglutathione levels are often associated with disease, compounds that modulate ADH3 activity might be of therapeutic interest. We performed a virtual screening with molecular dockings of more than 40,000 compounds into the active site of human ADH3. A novel knowledge-based scoring method was used to rank compounds, and several compounds that were not known to interact with ADH3 were tested in vitro. Two of these showed substrate activity (9-decen-1-ol and dodecyltetraglycol), where calculated binding scoring energies correlated well with the logarithm of the k _cat/K _m values for the substrates. Two compounds showed inhibition capacity (deoxycholic acid and doxorubicin), and with these data three different lines for specific inhibitors for ADH3 are suggested: fatty acids, glutathione analogs, and cholic acids.     

Esterase activity in the hepatopancreas ofMacrobrachium lamarrei (Crustacea: Decapoda)

Summary The activity of the hepatopancreatic esterase of the fresh water prawnMacrobrachium lamarrei was optimal at pH 7.4 and temperature 40°C. The activity increased with the increase in incubation period and enzyme concentration. The Michaelis constant (K_m) of the enzyme was 2.1×10^–3M.The investigations are a part of the thesis presented to University of Lucknow, India.Acknowledgments. The authors are grateful to the University Grants Commission, India for the award of a Junior Research Fellowship.     

Profound hypothermia in golden hamsters (Mesocricetus auratus) induced by serotonergic potentiating and noradrenergic inhibiting drugs

Summary Profound hypothermia (6°C) was induced in cold exposed golden hamsters (Mesocricetus auratus) by a combination of drugs that potentiate brain serotonergic activity (fluoxetine and pargyline) and inhibit noradrenergic activity (alpha-methyl-p-tyrosine). Individual drugs and combinations of 2 were ineffective.Acknowledgements. We acknowledge the support of a research grant PCM74-05158 A01 to A.H.M. from the National Science Foundation (USA) and thank Lilly Research Laboratories, Indianapolis, Indiana, for the gift of fluoxetine (Lilly 110140).