Influence of omega-6/omega-3 rich dietary oils on lipid profile and antioxidant enzymes in normal and stressed rats.

To evaluate the influence of omega-6/omega-3 poly unsaturated fatty acid (PUFA) containing oils on lipid profile and endogenous antioxidant enzymes in normal and stressed (immobilization) rats, 28 day old male Wistar rats were fed for 45 days with fat enriched special diet (10% fat) prepared with sunflower oil (SO)--omega-6 rich, mustard oil (MO)--omega-3 rich and groundnut oil--control respectively. SO treated normal rats have significantly reduced total cholesterol, high density lipoprotein-cholesterol (HDL-C) and catalase thereby significantly increased the atherogenic index (AI) and lipid peroxidation (LPO). However, treatment with MO increased superoxide dismutase; decreased LPO significantly. Under stress conditions AI and LPO were significantly high with SO and significantly less with MO. In addition, SO decreased HDL-C whereas MO decreased non-HDL-C significantly. Results suggest a protective role against AI and LPO in normal and stress conditions in MO. The quantity of omega-3 fatty acids in dietary oil may play a crucial role in the body against atherogenicity. The findings signify that not just PUFA, but type of PUFA present in dietary oil used is important.

Intrastrain variations in anxiolytic effect of nitrazepam in mice.

This study investigated the individual differences in the baseline anxiety and anxiolytic effect of nitrazepam in Balb/c mice. Initially mice were sorted according into low, intermediate and high anxiety groups (LA, IA and HA) based on the number of entries to and time spent in open arms in elevated plus maze. Later, anxiolytic effect of nitrazepam (2 mg/kg, p.o) in LA, IA and HA mice was evaluated using hole board and light/dark tests. In Hole board test, LA mice made more number of head dippings and spent more time during head dippings, while HA mice made less number of head dippings and spent less time during head dipping when compared to that of IA mice. In light/dark test LA mice made more reentries to and spent more time in bright compartment, while HA mice made few reentries to and spent less time in bright compartment. Results suggest that mice of a single strain differ in their baseline anxiety and anxiolytic effect of nitrazepam.

Role of emotionality on inter and intrastrain variations in imipramine response. a comparative study in Balb/c and Swiss mice.

Association between emotionality and effect of imipramine on immobility time in forced swimming test was investigated in Swiss and Balb/c mice. Mice of both the strains were segregated into normal emotional (mean +/- 1SD), low emotional (> mean + 1SD) and high emotional (< mean - 1SD) based on their performance with respect to each indices of emotionality in novel arena and elevated plus maze. Baseline immobility and effect of imipramine (20 mg/kg, po) on immobility time was evaluated in these emotionally different groups of mice using forced swimming test model. Baseline immobility time of low emotional mice was found to be significantly less (P<0.01) and that of high emotional mice was found to be significantly more (P<0.01) when compared to normal emotional mice of both the strains. Immobility time after imipramine administration was found to be significantly less (P<0.05) with low emotional mice and significantly more (P<0.01) with high emotional mice when compared to normal emotional mice of both the strains.