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Biomedical subjects

B K Patnaik

Publications and source records attributed to B K Patnaik.

At least 37 records · Page 2Linked to original sources
PubMed1982

Some biochemical changes in the ageing heart of the male garden lizard.

The SDH activity of cardiac muscle homogenates reached a peak level in the middle-aged lizards followed by a decline in the old. The inhibition of enzyme activity by oxaloacetate, a competitive inhibitor, declined with advancing age. Both salt and acid solubilities of cardiac muscle collagen declined with advancing age of the lizard. An age-related accumulation of total collagen was evident per organ basis but a reverse trend prevailed on the basis of relative value. Quantitative estimations revealed a loss of DNA in ageing heart; per organ basis the DNA content increased till the lizards were middle-aged showing no further change thereafter. On the other hand the RNA content and the RNA/DNA ratio of cardiac muscle declined between young and middle-aged followed by a rise in the old lizards. The protein content increased with rise in fresh weight of heart during ageing.

Aging↗
PubMed1981

Thermal inactivation and oxaloacetate inhibition of hepatic respiratory metabolism in male garden lizards of three different age-groups.

Thermal inactivation of hepatic succinic dehydrogenase (SH) (EC 1.3.99.1) at 51 +/- 1 degrees C resulted in a higher degree of inhibition in middle-aged and old than in young lizards. The oxaloacetate inhibition of SDH activity and that of oxygen uptake of liver homogenates after 1 h of incubation also showed a similar pattern of age dependency. With increase in time interval (from 15 to 60 min) the young and to some extent the middle-aged lizards showed a partial recovery from inhibition of oxygen consumption of liver homogenates, but not the old animals.

Aging↗
PubMed1981

Effect of alloxan diabetes on the characteristics of collagen of cotton pellet granuloma and dorsal skin of Swiss mice.

Alloxan diabetes in Swiss mice of both sexes accelerated the ageing of collagen in newly formed cotton pellet granuloma concomitant with its similar effect on dorsal skin. The degree of response of collagen to alloxanization was dependent on the duration of the treatment and the sex of the animal. It is suggested that the physiologically altered state resulting from alloxanization leads to the formation of metabolites that act as promotants of collagen cross-linking in both existing and newly formed connective tissues.

Aging↗
PubMed1980

Effect of age and short-term cold stress on SDH activity and oxygen consumption of lizard brain.

The SDH (EC 1.3.99.1) activity of both whole brain and mid-brain homogenates and the specific oxygen consumption of mid-brain homogenate are significantly lower in old than in young lizards. Short-term cold stress (1 h at 0--4 degrees C) did not induce a significant change in the enzyme activity of the whole brain homogenate, but the activity was depressed in the mid-brain homogenate of lizards of both age groups, not showing appreciable age-dependency of the response. The respiratory rates of mid-brain homogenates of both young and old lizards were depressed following cold stress. Lizards of both age groups showed almost complete reversal of depressed respiratory rate during the same time, i.e. between 30 and 45 min of rewarming at room temperature (30 +/- 2 degrees C). Though statistically insignificant the old lizards showed a trend of slower rate of recovery as compared to the young lizards, suggesting further detailed studies on the problem in question.

Aging↗
PubMed1980

Age-related changes in oxygen consumption and the SDH activity of liver homogenate of male garden lizards: effect of malonate and short-term cold stress.

The respiratory rate of liver homogenate in the male garden lizard showed a decline with advancing age. The mitochondrial marker enzyme, SDH of the liver, reached a peak activity in the middle-aged group and then declined. Malonate inhibition of the enzyme activity was greater in young and middle-aged groups of lizards than in old. Short-term cold stress (1 h at 0--4 degrees C) showed a differential age effect inducing a decline in enzyme activity of the middle-aged group and a rise in the old.

Aging↗