Biomedical subjects

R Ravindran

Publications and source records attributed to R Ravindran.

13 recordsLinked to original sources

PubMed2006

Serotonin turnover in different duration of sleep recovery in discrete regions of young rat brain after 24 h REM sleep deprivation.

Sleep plays an important role in restorative function and serotonin (5-hydroxytryptamine: 5HT) equally plays important roles in sleep. Though various studies have revealed the roles of 5HT in sleep/wake cycle, the mechanism involved is yet unclear. In the present study we investigated alteration of the 5HT turnover in various regions of the young rat brains after 24 hours (h) REM sleep (sREM) deprivation to elucidate the roles of 5HT in sleep restoration function in the these regions. The 5HT turnover was evaluated by the ratio of 5-hydroxyindole acetic acid against 5HT. The sREM deprivation was performed by the inverted flowerpot technique. The 5HT turnover showed significant alteration in the all regions of the brain examined after 24h sREM deprivation, particular depending on the brain region. These results revealed that sREM modulates the 5HT turnover in the brain with region specificity and this may be one of the restorative functions of sleep indicating that sREM is regionally generated.

Analysis of Variance↗

PubMed2006

Plumbago zeylanica action on blood coagulation profile with and without blood volume reduction.

Plumbago zeylanica (PZ) is extensively used in Indian systems of medicine for its medicinal properties. The structure of its active principle is similar to that of vitamin K. Its effect on blood coagulation profile after chronic administration has not been reported so far. The PZ extract (2 mg/kg body weight) and napthoquinone (2 mg/kg body weight) given to individual groups were screened for its effect on bleeding time (BT), clotting time (CT), prothrombin time (PT), platelet count and platelet adhesion in albino rats after 1-day, 15-day and 31-day treatment. There was no change in the platelet count in the treated groups when compared to the control levels. But the platelet adhesion was significantly decreased after PZ and also napthaquinone-treated animals in both with and without blood volume reduction after 15th as well as 31st day. Since the napthoquinone-treated group also showed similar response the changes observed after PZ treatment may be due to this component. Even at a lower dosage level (2 mg/kg body weight), the chronic PZ administration prolongs the bleeding time by altering platelet adhesiveness and the coagulation.

Animals↗

PubMed2006

Biogenic amine changes in brain regions and attenuating action of Ocimum sanctumin noise exposure.

Broadband white noise exposure (100 dB) in wistar strain male albino rats significantly increased the levels of dopamine (DA), serotonin (5-HT) and 5-HT turnover in many of the discrete brain regions (cerebral cortex, cerebellum, hypothalamus, hippocampus, pons-medulla and corpus striatum) during sub-chronic noise exposure (4 h daily for 15 days). In acute (4 h for 1 day) and chronic noise exposures (4 h daily for 30 days) the levels were significantly altered only in certain regions. The turnover study of serotonin clearly indicates that neurotransmitter level alone cannot be an indicator, as in some brain regions the rate of synthesis matched with the degradation in order to maintain the normal levels. The intraperitoneal administration of 70% ethanolic extract of Ocimum sanctum(OS) at the dosage of 100 mg/kg body weight to animals subjected to noise exposure has prevented the noise induced increase in neurotransmitter levels without affecting the normal levels. This indicates that OS can be a probable herbal remedy for noise induced biogenic amine alterations.

Animals↗

PubMed2006

Serotonin turnover in discrete regions of young rat brain after 24 h REM sleep deprivation.

The present study has attempted to elucidate the alteration of serotonin turnover after 24 h REM sleep deprivation in different regions in brain of young rat. Sleep deprivation was induced by the inverted flower pot technique. Results of this study show increased serotonin turnover after 24 h REM sleep deprivation in all the brain regions except in the hypothalamus. The decreased 5-HT ratio shows increased serotonin in the hypothalamus after 24 h sleep deprivation. This study indicates increased activity of serotonergic neurons in the hypothalamus after 24 h sleep deprivation. This also indicates that the hypothalamus plays a role in the immediate compensatory mechanism during 24 h REM sleep deprivation in young rats.

Animals↗

PubMed2003