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U. Srineetha ¹, M. Venkata Reddy ², M. Bhaskar ¹

Affiliations
1 Department of Zoology, Sri Venkateswara University, Tirupati-517 502, A. P., IN
2 Department of Zoology, Sri Krishnadevaraya University, Anantapuramu-515 055, A. P., IN

Abstract

The present study was aimed to investigate the total oxygen consumption of freshwater fish Cyprinus carpio during exposure and acclimation to sublethal acidic pH (5.0) medium. The oxygen consumption of fish significantly depleted in all the days of exposure to sublethal acidic pH 5.0 starting from first day to fourteen days of exposure. The rate of total oxygen consumption depletion was higher on first day. From the second day onwards a gradual decreasing trend was observed in the depletion up to 14th day of exposure. The unit oxygen consumption of fish on exposure to sub-lethal pH medium exhibited significant depletion when compared to control. The rate of depletion was maximum in the initial days of exposure and was reduced gradually in twelfth and fourteenth day of exposure. But, at day 14th not significant decrease was observed in both the parameters of the experimentation. This observation indicates that the fish was capable of regulating their metabolic modulations and physiological functions through acclimation process to be the possible reason for the successful survival of fish in acidifying water. The reduced oxygen consumption of fish on exposure to sublethal acidic medium confirms the prevalence of hypoxic condition in the surrounding medium.

Keywords

Acidic pH, Oxygen Consumption, Cyprinus carpio L.

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M. Haranadha Reddy ¹, M. Venkata Reddy ¹, K. Radhakrishnaiah ¹

Affiliations
1 Department of Zoology, Sri Krishnadevaraya University, Anantapur-515 055, A.P., IN

Abstract

Small (20±2 g) and large (40±2 g) size groups of the freshwater snail Pila globosa were exposed to different concentrations of nickel (mg/L), and 96 hr LC₅₀ through percent and probit mortality of the animals and also by Dragstead and Behren's method were determined. There was a linear relationship between the percent or probit mortality and the nickel concentration of both the size groups of snails. Thus, the percent and/or probit mortality increased with the increase in concentration of nickel. The percent mortality plotted against log concentration of nickel gave sigmoid curves, whereas the probit mortality plotted against log concentration gave straight lines in both the groups of snails. The 96 hr LC₅₀ obtained for small and large size groups of snails are 117.6 mg/L and 206.3 mg/L respectively. These values obviously indicated a significant (P<0.001) increase in the LC₅₀ of nickel with the increase in the size of the snail. The results of the present study indicate that the small size groups of snails are more sensitive to nickel than the large size groups.

Keywords

Pila globosa, Toxicity Evaluation, Nickel Toxicity, 96 hr LC₅₀.

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M. Venkata Reddy ¹, K. Radha Krishnaiah ¹

Affiliations
1 Department of Zoology, Sri Krishnadevaraya University, Anantapur (A.P.), IN

Abstract

A decrease in the levels of glucose, glycogen and the activity of succinate dehydrogenase (SDH) along with an increase in the levels of lactate, pyruvate and the activity of lactate dehydrogenase (LDH) was observed in the epididymis of male and uterus of female rats on adrenalectomy (ADX) when compared with sham operated (SO) rats at days 15 and days 30 of experimentation. These results indicated suppression of oxidative metabolism and elevation of anaerobic glycolysis in the reproductive tissues of the male and female rats on adrenalectomy leading to the decrease in their energy levels. The magnitude of decrease, however, was significantly more in the uterus of female ADX rats than in epididymis of male ADX rats. And in both the animal groups the degree of decrease in the level of energetics was more at days 30 than at days 15. The over all results suggest that the impact of adrenalectomy on energetics was more in females than in males and it increases with the duration of experimentation.

Keywords

Albino Rats, Adrenalectomy, Epididymis, Uterus, Energetics.

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M. Venkata Reddy ¹, K. Radhakrishnaiah ²

Affiliations
1 Department of Zoology, Yogi Vemana University, Kadapa (A.P), IN
2 Department of Zoology, Sri Krishnadevaraya University, Anantapur (A.P), IN

Abstract

A significant decrease in the levels of total proteins along with an increase in the levels of free amino acid (FAA) and ammonia and activities of protease, alanine aminotransferase (AlAT),aspartate amino transferase (AAT) and glutamate dehydrogenase(GDH) were observed in the liver of male and female rats on adrenalectomy (ADX) at day 15 and day 30 compared with sham operated (SO) rats. These results indicated significant proteolysis and active trans- deamination in the hepatic tissue of rats on adrenalectomy. Increase in protease activity and amino acid levels could be due to the turnover of proteins for metabolic reorganization. The magnitude of those changes were significantly more in the liver of female ADX rats than in the liver of males. It revealed more susceptibility of females to adrenalectomy than the males. Longer the duration of adrenalectomy more is the protein breakdown in both the sexes as noticed from day 15 to day 30. Corresponding to the changes in protein levels some degenerative changes in the histology were observed in the liver of male and female ADX rats at day 15 day 30 compared to normals. A mild degree of destruction of hepatocytes with darkened nuclei and widening of sinusoidal spaces in few regions were observed at day 15 and severe cytoplasmic and nuclear damage at day 30 in the liver of ADX males suggest that adrenalectomy leads to decreased protein synthesis. The female ADX rats showed widening of sinusoidal spaces in few regions at day 15 and on day 30 the nuclei of hepatocytes shrunken, while karyolysis is also observed in few nuclei. These changes support that female rats proved to more vulnerability on ADX stress than the male ADX rats. In conclusion the observations, indicated proteolysis and active trans-deamination to favour to gluconeogenesis for energy production in the hapatic tissues of rats on adrenalectomy. It could lead to structural disruption and decreased metabolic ability that appeared more in females than in males on ADX, and in both the sexes it increased with the duration of adrenalectomy.

Keywords

Albino Rats, Adrenalectomy, Liver, Proteins, Histology.

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