Showing papers by "Chandra Mohini Chaturvedi published in 2009"
TL;DR: It is concluded that normal somatic and gonadal growth of pre-puberal mice may be suppressed with an 8-hr phase relation of circadian serotonergic and dopaminergic oscillations, which accelerated the rate of gonadal maturation and led to more or less similar gonadal development as in the control mice.
19 citations
TL;DR: It is concluded that water deprivation down regulates the mRNA expression of AVT receptor VT2 as well as POMC but stimulates adrenal function and it is suggested that in addition to the release of magnocellular AVT into the neurohypophysis to act as antidiuretic hormone following water deprivation, AVT may also modulate HPA axis to cope with the osmotic stress.
17 citations
TL;DR: It is evident that 5-HTP and L-DOPA given at the interval of 8h, as well as melatonin, are potent inhibitors of gonadal development, and the gonado stimulatory effect of the 12-h temporal relationship of the neurotransmitter precursors is masked by the inhibitory effect of melatonin.
7 citations
01 Dec 2009
TL;DR: In this article, female mice were exposed to 245 GHz electromagnetic field (EMF) for 2 hours/day at power density of 1,250 mW/cm2 for the period of 30 days.
Abstract: To study the effect of microwave radiation on the early stages of pregnancy (implantation) and DNA damage in brain cells, female mice were exposed to 245 GHz electromagnetic field (EMF) for 2 hours/ day at power density of 01250 mW/cm2 for the period of 30 days (pre-mating period, 22 days; mating period, 5 days; post mating period, 3 days)
6 citations
TL;DR: Data indicate that high plasma T4 level stimulates adrenal activity and may also modulate function of the pituitary–adrenal axis during dehydration, although exact mechanism is not clear.
Abstract: The role of thyroid hormones in the regulation of adrenal function during stress has been documented in mammals, but only limited reports are available in avian species. The present study was undertaken to analyze the effect of hyper- or hypothyroidism on the adrenal activity under control (hydrated) and osmotically stressed (water deprived, WD) conditions, with special emphasis on the expression of arginine vasotocin receptor VT2 (VT2R) in pituitary corticotrophs. Chickens were made hyper- or hypothyroidic by injecting thyroxine (T4) and 2-thiouracil (TU), respectively for 14 days. After 10 days of injections, one sub-group of both, T4- or TU-treated chickens were subjected to osmotic stress by water deprivation. Hyperthyroidism stimulated adrenal steroidogenic activity compared to euthyroid control birds, but no change was observed in the expression of VT2R. On the other hand, TU-induced hypothyroidism however showed no effect on adrenal gland, but a significant increase in the expression of VT2R was observed. Neither hyper- nor hypothyroidism altered pro-opiomelanocortin (POMC) mRNA levels. Following osmotic stress, no effect was observed either on the adrenal gland or on the VT2R expression in hyperthyroidic birds, but in hypothyroidic birds, osmotic stress stimulated adrenal steroidogenic activity and decreased VT2R expression in comparison to its respective controls (T4 or TU). Expression of POMC mRNA was again unaltered following osmotic stress. Although exact mechanism is not clear, the data indicate that high plasma T4 level stimulates adrenal activity and may also modulate function of the pituitary-adrenal axis during dehydration.
5 citations
TL;DR: Findings confirm a role for AVT, mediated by the VT2 receptor, in regulating ACTH secretion during stress and suggest that corticotroph VT2 receptors levels may be dynamically regulated depending on the HPA axis activity.
5 citations
Journal Article•
TL;DR: It is concluded that specific relation of serotonergic and dopaminergic oscillation induces reproductively quiescent or active condition out of the season as a function of their time relation and suggests that, circadian organization may regulate reproductive and metabolic seasonality irrespective of the phase of the annual gonadal cycle.
Abstract: Present study investigates the role of temporal phase relation of serotonergic and dopaminergic oscillations in the regulation of seasonal reproduction in summer breeding Jungle bush quail, Perdicula asiatica and autumn breeding rain quail, Coturnix coturnix coromandelica. Two sets of experiments were performed in month of August, in reproductively quiescent (RQ) bush quail and reproductively active (RA) rain quail. In experiment I, both quails received the serotonin precursor, 5-HTP and the dopamine precursor, L-DOPA (5 mg/100 gm body weight/day for 13 days) at the interval of 8-hr or 12-hr. At the termination of the study (30 days post treatment), 8-hr suppressed and 12-hr increased body weight and testicular development compared to their respective controls in both the species of quail. However, in RA rain quail, testicular development in 12-hr group was similar to control. Further, in RQ bush quail, while adrenal activity of 8-hr group was more or less similar to control, 12-hr relation stimulated the activity of steroidogenic cords. On the other hand, in RA rain quail, control and 12-hr quail adrenal activity was similar while that of 8-hr showed suppression. In experiment II (quails receiving total dose of experiment I, i.e. 32.5 mg/100 gm body weight/ day for 2 days only, and sacrificed 30 days thereafter), response of the birds were similar to that of the experiment I. These findings indicate that, 8-hr and 12-hr relation of the 5-HTP and L-DOPA administration induced suppression and stimulation of the gonadal and adrenal function respectively, irrespective of the phase of the annual gonadal cycle of the two species of quail. It is concluded that specific relation of serotonergic and dopaminergic oscillation induces reproductively quiescent or active condition out of the season as a function of their time relation. These findings also suggest that, circadian organization may regulate reproductive and metabolic seasonality irrespective of the phase of the annual gonadal cycle.