Volume 6, Issue 3
September 1984, pages 249-336
pp 249-255 September 1984
Polyacrylamide gel disc electrophoretic technique was used to examine the esterase pattern of nead, haemolymph, alimentary canal., ovary and testis of the Uzi fly. The zymograms revealed the varied pattern of esterases both in number and type. This varied pattern suggested several roles for these enzymes present in different tissues
pp 257-261 September 1984
Role of peripheral and central noradrenaline and 5-hydroxytryptamine in the carrageenin-induced pedal oedema in rats was studied using agents which influence catecholamine synthesis and receptor activity of noradrenaline and 5-hydroxytryptamine. Reserpine, guanethidine, α-methyl-p-tyrosine, diethyldithiocarbamate, 6-hydroxydopamine, phenoxybenzamine, phentolamine, chlorpromazine and yohimbine markedly inhibited carrageenin-induced pedal oedema. However, 6-hydroxydopamine given intracerebroventricularly, 5,6-dihydroxytryptamine,p-chlorophenylalanine, lower dose of yohimbine, pro pranolol, haloperidol, cyproheptadine and mepyramine did not alter the carrageenin-induced oedema, whereas, cyproheptadine and mepyramine given simultaneously, markedly inhibited carrageenin-induced oedema. Our studies indicate that the process of oedema formation in rats by carrageenin involves both the peripheral noradrenaline and 5-hydroxytryptamine
pp 263-276 September 1984
Induction of follicle stimulating hormone receptor in the granulosa cells of intact immature rat ovary by diethylstilbesterol, an estrogen, has been studied.
A single injection of 4 mg of diethylstilbesterol produced 72 h later a 3-fold increase in follicle stimulating hormone receptor concentration as monitored by [125I]-oFSH binding to isolated cells. The newly induced receptors were kinetically indistinguishable from the preexisting ones, as determined by Lineweaver-Burk plot of the binding data. The induced receptors were functional as evidenced by increased ability of the granulosa cells to incorporate [3H]-leucine into cellular proteins.
Neutralization of endogenous follicle stimulating hormone and luteinizing hormone by administering specific antisera had no effect on the ability of diethylstilbesterol to induce follicle stimulating hormone receptors, whereas blockade of endogenous prolactin secretion by ergobromocryptin administration significantly inhibited (∼ 30 %) the response to diethylstilbesterol; this inhibition could be completely relieved by ovine prolactin treatment. However, ovine prolactin at the dose tried did not by itself enhance follicle stimulating hormone receptor level.
Administration of ergobromocryptin to adult cycling rats at noon of proestrus brought about as measured on diestrusII, (a) a reduction of both follicle stimulating hormone (∼ 30 %) and luteinizing hormone (∼ 45 %) receptor concentration in granulosa cells, (b) a drastic reduction in the ovarian tissue estradiol with no change in tissue progesterone and (c) reduction in the ability of isolated granulosa cells to convert testosterone to estradiol in response to follicle stimulating hormone. Ergobromocryptin treatment affected only prolactin and not follicle stimulating hormone or luteinizing hormone surges on the proestrus evening. Treatment of rats with ergobromocryptin at proestrus noon followed by an injection of ovine prolactin (1 mg) at 1700 h of the same day completely reversed the ergobromocryptin induced reduction in ovarian tissue estradiol as well as the aromatase activity of the granulosa cells on diestrus II, thus suggesting a role for proestrus prolactin surge in the follicular maturation process
pp 277-282 September 1984
The effect of lipid lowering agents of plant origin garlic oil and guggulipid on the levels of catecholamine and dopamine Β-hydroxylase activity of normal and cholesterol fed rabbit tissues has been studied. The catecholamine levels and enzyme activity were found to be decreased in cholesterol (500 mg/kg body wt) fed animals. The feeding of garlic oil (5 mg/kg body wt) and guggulipid (100 mg/kg body wt) an exudate ofCommiphora mukul, to normal rabbits caused significant increase in the dopamine-Β-hydroxylase activity and catecholamine levels, while the feed helped the hypercholesterolemic rabbits to recover the decrease in catecholamine biosynthesis
pp 283-288 September 1984
The parent wild strainNeurospora crassa Em 5297a and three Ni2+ resistantNeurospora crassa mutants have been shown to excrete pyruvate into the culture medium in Ni2+ and Co2+ toxicities. Ni2+ has a more pronounced effect in this regard. The excretion is progressive with growth inhibition and is abolished by Mg2+ in all strains and by Fe3+ partially in the Em strain but not inNeurospora crassa NiR1. Pyruvate, citrate and malate supplementation reverse growth inhibition caused by excess Ni2+, but with concomitant suppression of Ni2+ accumulation. It is suggested that one of the features of Ni2+ toxicity inNeurospora crassa is a derangement in carbohydrate metabolism at step(s) beyond pyruvate and that this is possibly due to decreased invivo activity of Mg2+ dependent processes
pp 289-295 September 1984
A specific enterokinase inhibitor isolated from kidney bean (Phaseolus vulgaris) was immobilized on Affigel-10. Solubilized preparation of bovine and porcine enterokinases were bound to this matrix at pH 7.5 and the complex was dissociated by elution with l0 mM HCl, resulting in the isolation of the enzymes in homogeneous form as judged by gel chromatography on Sephadex G-200, and sodium dodecyl sulphate-polyacrylamide gel electrophoresis. However, human enterokinase could not be purified by this method in sufficient yield since it did not bind strongly to the insolubilized inhibitor.
pp 297-307 September 1984
The effect of a single subcutaneous administration of 7,12-dimethylbenz(a)anthracene, the powerful complete carcinogen, under the skin was studied in the rabbit. The study reports an ordered sequential biochemical and cytophotometric changes induced by the carcinogen. While the biochemical studies comprised of sequential quantitative estimations of DNA, RNA and protein per mg of skin, the cytophotometric studies consisted of the estimation of the level of macromolecules in a cell/nucleus, in different skin constituentsviz. epidermis, hair follicle shaft region and hair follicle bulb region. Biochemical results indicate an initial rise in the level of DNA and RNA and reduction in protein upto 20 days. From 40 to 60 days treatment duration there was a ‘steady-state’ showing a constant level of all the parameters while the highest peak was observed on the 80th day. The site of these biochemical changes among different skin constituents was determined with the help of cytophotometer which indicates the highest level of nucleic acids in epidermis region right from the initial stage (i.e. 10th day) to the 90th day of treatment in comparison to two other regions hair follicle shaft and hair follicle bulb regions. Histological studies, on the other hand, reveal a greatly, though gradual, increased nuclear area and the highest rate of proliferation only in hair follicle bulb region, thus suggesting a definite role of this region of the skin in the carcinogenesis. All these results suggest that the important event in the initiation phase of 7,12-dimethylbenz(a)anthracene mediated skin carcinogenesis in rabbit might be associated with epidermal region but the role of hair follicle bulb region should also be considered as of an equal significance during the process.
A conspicuous difference in the behaviour of rabbit skin constituents has been noted when the results of the study are compared with the earlier reports on mice
pp 309-314 September 1984
The light activated proton pump, bacteriorhodopsin was modified with varying amounts of flourescamine, the fluorescamine to protein ratio ranging from 1 to 100. The modified protein was washed free of excess of fluorescamine and reconstituted into phospholipid vesicles to check the proton pumping activity. Although the spectral investigations indicated chemical modification, the circular dichroism measurements pointed to an overall loss of the trimeric structure of the protein. The implications of the present study are that the modifying agent can interact non-specifically with the protein, altering its structural parameters, which in turn affects the function of the protein
pp 315-324 September 1984
The composition of volatile fatty acids in the biogas digester based on cattle manure as substrate and stabilised at 25°C showed that it contained 87–88% branched chain fatty acids, comprising of isobutyric and isovaleric acids, in comparison to 38 % observed in the digester operating at 35°C.
Mixed cellulolytic cultures equilibrated at 25°C (C-25) and 35‡C (C-35) showed similar properties, but rates of hydrolysis were three times higher than that observed in a standard biogas digester. The proportion of isobutyric and isovaleric were drastically reduced when C-25 was grown with glucose or filter paper as substrates. The volatile fatty acids recovered from C-25 (at 25°C) inhibited growth of methanogens on acetate, whereas that from C-35 was not inhibitory. The inhibitory effects were due to the branched chain fatty acids and were observed with isobutyric acid at concentrations as low as 50 ppm.
Addition of another micro-organismRhodotorula selected for growth on isobutyric completely reversed this inhibition. Results indicate that the aceticlastic methanogens are very sensitive to inhibition by branched chain fatty acids and reduction in methane formation in biogas digester at lower temperature may be due to this effect.
pp 325-330 September 1984
A study on the effect of retinolin vitro on the hemolysis of vitamin E deficient rat red blood cells showed that retinol enhanced the lysis of the E deficient cells as compared to the lysis of normal cells. The lipid peroxidation present during hydrogen peroxide induced lysis of E deficient cells was however markedly inhibited in the presence of retinol without affecting the rate of lysis. In an actively peroxidising system of non-enzymatic lipid peroxidation of rat liver or brain homogenates and of brain lysosomes incubated with human erythrocytes, no lysis was obtained; incorporation of retinol in such systems resulted in lysis but no peroxidation. Hydrogen peroxide generating substances almost completely inhibited the lysis of normal human erythrocytes by retinol, but linoleic acid hydroperoxide and auto-oxidised liver or brain homogenates and ox-brain liposomes increased the lysis. It is concluded that vitamin E deficient erythrocyte hemolysis may be augmented by retinol, an anti-oxidant, having a lytic function without the peroxidation of stromal lipids
pp 331-336 September 1984
Changes in the activity of hexokinase and lactate dehydrogenase isoenzymes in the three brain regions and heart were studied in the 6-Aminonicotinamide-treated rats. Drug administration decreased the particulate hexokinase and lactate dehydrogenase activity, but increased the soluble hexokinase
Volume 44 | Issue 5
Click here for Editorial Note on CAP Mode