Browsing by Author "C. Haldar"

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5-Methoxyindoles (MEL, 5-MT and 5-MTP) induced biochemical changes in the pineal gland of Indian palm squirrel, Funambulus pennanti
(1997) R. Sarkar; C. Haldar
An attempt was made to study the effect of 5-methoxyindoles (5-MIs) on the biochemical constituents (protein, cholesterol and serotonin) of pineal gland (PG) in a seasonally breeding rodent, F. pennanti. The squirrels received evening (1630-1700 hr) s.c. injection of melatonin (MEL; 20 μg/animal/day), 5-methoxytryptamine (5-MT; 20 μg/animal/day) and 5-methoxy-tryptophan (5-MTP; 20 μg/animal/day) during the two phases of reproductive cycle (active/inactive). The 5-MIs increased the pineal cholesterol (except 5-MT) and serotonin content during reproductive active phase without affecting the PG weight, its protein content and testes weight. On the other hand, during reproductive inactive phase, differential effects of different 5-MIs were noted. 5-MT increased the pineal protein and cholesterol content while 5-MTP increased the pineal protein content only. The PG weight showed a significant decrease whereas, testes weight increased after the MIs treatment. It can be suggested that 5-MIs had stimulatory effect on the biochemical constituents of PG in this seasonal breeder. The stimulation was more potent on the biochemical constituents when the PG was active and the squirrels were reproductively inactive.
A reproductive phase-dependent effect of dietary L-tryptophan on pineal gland and gonad of a nocturnal bird, Indian spotted owlet Athene Brama
(2001) P. Guchhait; C. Haldar
Unlike other temperate owls, Indian spotted owlet Athene brama possesses a well-developed pineal gland that secrets moderate amount of hydroxy- (serotonin) and methoxy- (melatonin) indoles in circulation. However, in this study, we have reported the response of this endocrine gland to exogenous L-Tryptophan (precursor of the above indoles), and also its effect on gonads of this nocturnal bird. During breeding phase or pineal inactive phase (March), oral treatment of L-Trp (0.5 mg/100 g Bwt/day) significantly increased the pineal gland wt and plasma melatonin (MEL) level, while decreased the gonadal wt and plasma sex steroids levels (estradiol and progesterone in female and testosterone in male). Interestingly, during reproductively quiescent phase or pineal active phase (August), similar amount of L-Trp significantly decreased the plasma MEL level, while increased the above sex steroid levels in plasma. Finally, the results show a clear reproductive phase-dependent inverse effect of L-Trp on pineal gland and gonads for both sexes of the spotted owlets, and suggest that the therapeutic use of this amino acid would be a great advantage for controlling the reproduction of these economically important birds.
Annual pineal and testicular cycle in the indian jungle bush quail, Perdicula asiatica, with reference to the effect of pinealectomy
(1990) C. Haldar; M. Ghosh
The annual testicular cycle of Perdicula asiatica has a single peak which appears to be under the dual influence of the environment and the pineal gland. An inverse relationship was noted between pineal gland and testicular weight cycle. Pinealectomy, after 60 days, retarded testicular growth in the progressive phase, inhibited activity of the gonad in the active phase, and accelerated gonadal regression in the regressive phase. This complete study of short-term pinealectomy effects on the annual testicular cycle of a tropical bird for the first time reflects both the essentialness of the pineal gland to the maintenance of proper testicular cyclicity under natural environmental conditions and the progonadotropic nature of the pineal gland. © 1990.
Annual variation in lung associated immunity and season dependent invasion of Alternaria alternata in lungs of Indian jungle bush quail, Perdicula asiatica
(2012) R.K. Kharwar; C. Haldar
The purpose of this study was to evaluate annual variation in lung associated immune system (LAIS) along with general immunity of Perdicula asiatica an Indian tropical bird. Variation in immunological parameters such as size of bronchus associated lymphoid tissue (BALT) and non-BALT nodules, percent stimulation ratio (%SR) of isolated lung lymphocytes, total leukocyte count (TLC) and lymphocyte count (LC) was noted along with circulatory hormonal levels i.e. melatonin and testosterone for two consecutive years. Lowest immune status in terms of small BALT and non-BALT nodular size, %SR, TLC and LC was noted in the month of April. Considering the relation between annual variation of the peripheral hormones melatonin and testosterone and immune status of this bird, we observed an inverse relationship. It could be that high testosterone (an immunosuppressor) and low melatonin (an immunostimulator) levels during summer months are responsible for low immunity. While studying annual variation in LAIS we observed a fungal pathogen Alternaria alternata present in the lungs only during April suggesting that invasion occurred at a particular month of harvest (April). During the month of April low lung immune status was recorded, which could be responsible for such an invasion. This bird is a game bird and consumed as food by common rural people. If this fungus is being ingested along with the birds it may cause diseases like bronchitis, asthma, etc. in human being. Hence, gaming of this bird during summer month (April) should be avoided. © Koninklijke Brill NV, Leiden, 2012.
Annual variation of plasma melatonin following pinealectomy and melatonin administration in Indian tropical rodent, Funambulus pennanti
(2004) C. Haldar; S. Sharma; S.S. Singh
Pinealectomy (Px) and melatonin (Mel) administration is known for its effect on reproductive and behavioural rhythms. To date no report is available to suggest the effect of Px and Mel administration on the annual variations of plasma Mel itself in any tropical seasonally breeding rodent. We report here that a statistically significant annual oscillation of Mel existed in sham operated control squirrel, F. pennanti. The exact peak value of Mel was noted some time in November (∼13th ± 8 days), which was certainly due to short photoperiod and low ambient temperature. Px decreased the melatonin level most significantly. Mel injection to Px squirrel entrained the phase of Mel, though the amplitude was not completely achieved but had a peak melatonin concentration in January (∼2 months phase delay). Exogenous Mel administration to sham operated squirrel decreased amplitude of melatonin during the months of March-July leading to early gonadal regression but could not alter the amplitude of Mel in November and December, while the peak value was phase delayed by ∼2 months (January). We may suggest, therefore, that the pineal gland of this squirrel is essential for maintaining its own rhythm, which is an adaptive significance of this tropical rodent for the perpetuation of the species. © VSP 2004.
Chronohaematological changes in the lizard Calotes versicolor after pinealectomy
(1981) C. Haldar; J.P. Thapliyal
[No abstract available]
Circadian rhythms of melatonin and sex steroids in a nocturnal bird, Indian spotted owlet Athene brama during reproductively active and inactive phases
(Swets en Zeitlinger B.V., 1999) P. Guchhait; C. Haldar
The epiphyseal neurohormone melatonin (MEL) exhibits circadian cyclicity, as noted extensively in diurnal vertebrates although very little information is available regarding nocturnal species. We have studied the MEL rhythmicity with 24-hour periodicity in a tropical nocturnal bird, Indian spotted owlet Athene brama, which possesses a well-developed pineal organ. We performed our study during two crucial reproductive phases (active and inactive), when the pineal gland activity in owlet exists in inverse states, i.e., inactive and active respectively. Independent of sex, the circadian rhythm of plasma MEL in owlets showed a two-peak cyclicity with a smaller peak at around 1400 h and the higher one at about 0200 h, while the lowest value was found at 1000 h. The night (0200 h) peak activity of plasma MEL in owlet has a resemblance with the earlier findings in diurnal birds and strongly suggests that independent of species habit the peak activity of MEL is invariably dark dependent. However, the daytime peak of MEL may be due to the daytime hiding nature of this nocturnal bird. Interestingly, it was also noted that the hours of peak activity of MEL (1400 and 0200 h) were the same during both of the reproductive phases, though the environmental day length was longer and ambient temperature was higher during the reproductively inactive phase. During daytime these birds hide in a dark burrow where, in general, the intensities of light and temperature are less, and the amplitude of variations of these factors is not prominent. Hence, the seasonal variations in these oscillatory components may not have affected the entrainment of the owlet pineal oscillator, which regulates the daily MEL rhythm in a similar pattern during both the studied phases. On the other hand, a single circadian peak (around 1000 h) circadian cyclicity of gonadal steroids (i.e., testosterone in the male and estradiol and progesterone in the female) showed an inverse relationship with plasma MEL. Possibly, MEL regulates the daily steroidogenic status in owlets by an inhibitory influence.
Comparative view of pineal gland morphology of nocturnal and diurnal birds of tropical origin
(Wiley-Liss Inc., 2001) C. Haldar; K.S. Bishnupuri
Although having a similar developmental pattern, the pineal gland of tropical birds varies in shape, size, and morphology, probably more than any other part of the avian brain. Following the old classification, we noted a solid follicular (transitional) type of the pineal gland in the nocturnal bird Athene brama, and a tubulo-follicular and elongated tubular types of pineal gland in diurnal birds Perdicula asiatica and Euroloncha punchulata, respectively. Detailed light (LM) and electron microscopic (EM) studies of the pineal gland from these tropical birds revealed the presence of a well-developed, functionally active gland in nocturnal birds (contrary to reports available until now). Unlike diurnal birds, the nocturnal bird A. brama has no deep pineal in the posterior region (near the habenular commissure). It could be that the deep encephalic receptors have no/fewer functions in nocturnal birds. At present, we were unable to define the significance of deep pineal in these tropical avian species. A notable difference in the proximodistal orientation of intrapineal follicles and parenchymatous cells was noted among these birds due to different habitats. Ultrastructurally, the pinealocytes exhibited great similarities in terms of secretory organelles, except for the presence of some peculiar membranous structure in E. punchulata. The pinealocytes have rudimentary photoreceptive features (e.g., outer segment) along with cytoplasmic organelles for secretory activity, suggesting both photosensory and photosecretory types of function. The present study also suggests more heterogenicity in pineal gland morphology (cellular architecture) among diurnal birds than the nocturnal one. © 2001 Wiley-Liss, Inc.
Daily variation in antioxidant enzymes and lipid peroxidation in lungs of a tropical bird Perdicula asiatica: Role of melatonin and nuclear receptor RORα
(Elsevier Inc., 2012) R.K. Kharwar; C. Haldar
The wild animals are exposed in nature to more oxidative stress than any laboratory animals. Studies on oxidative stress of brain, liver and kidney are quite common while very less reports are available on respiratory system when it is the most susceptible organ to various stressors. We checked the oxidative stress of lung tissue of a wild seasonally breeding bird . Perdicula asiatica by noting down the daily variation in antioxidant enzymes (superoxide dismutase and catalase) levels, lipid peroxidation in terms of malondialdehyde level and total antioxidant status during reproductively active (RAP) and inactive phase (RIP). On the other hand melatonin has been accepted as free radical scavenger acting via receptor (nuclear receptor) or non receptor pathway. To pin point the role of melatonin in regulation of antioxidant enzymes via non receptor mediated pathway in lungs of bird, we checked variation in the nuclear melatonin receptor RORα. Antioxidant enzymes (superoxide dismutase and catalase) exhibited a marked 24. h rhythm in lungs being high during night time and coincided almost with the peak of melatonin and total antioxidant status where as malondialdehyde level and nuclear receptor RORα showed inverse relationship with all the above mentioned parameters. These findings suggest that melatonin might be acting as an antioxidant for the free radical load of lung tissue of a tropical bird . P. asiatica and its action might be via nuclear receptor RORα. © 2012 Elsevier Inc.
Daily variation in antioxidant enzymes lipid peroxidation in thyroid and plasma level thyroxine and triiodothyronine levels of a tropical bird Perdicula asiatica during reproductively active and inactive phases
(Taylor and Francis Ltd., 2017) V.K. Verma; S.K. Yadav; C. Haldar; R.K. Tripathi
The aim of this work was to study the variations in the interference of neuroendocrine pineal gland and metabolically active thyroid gland in a tropical bird, Perdicula asiatica. Maximum pineal gland activity (pineal weight and melatonin level), minimum thyroid gland activity (weight, T3/T4 and thymidine kinase activity) along with less oxidative load (MDA level, SOD, CAT and ABTS activity) were observed during reproductively inactive phase (RIP) was observed. Further, a robust and significant rhythmicity was noted in melatonin levels during RIP and RAP, but no significant rhythmicity was noted in T4/T3 level by cosinor analysis. Overall, melatonin and thyroid circadian profile suggested that melatonin might be acting as an antioxidant molecule with time of the day effect in rescuing thyroid gland from free radical load in birds. © 2016 Informa UK Limited, trading as Taylor & Francis Group.
Development of pineal complex in Calotes versicolor
(1977) C. Haldar; J.P. Thapliyal
[No abstract available]
Development of pineal gland in a tropical Indian water-snake, Natrix piscator
(1987) C. Haldar; R. Pandey
[No abstract available]
Diurnal variations in circulating estradiol, testosterone, melatonin and Harderian gland porphyrin concentration in Indian palm squirrel, Funambulus pennanti
(1996) C. Haldar; S. Dubey
A two-peak cyclicity in the plasma level of melatonin, estradiol/testosterone and Harderian porphyrin was noted in F. pennanti. An inverse relationship of Harderian porphyrin with plasma melatonin and a direct relation of it with plasma estradiol/testoserone level were also observed, suggesting that the variation of Harderian porphyrin concentration may be under the control of both, circulating melatonin and gonadal steroids.
Effect of 5-hydroxyindoles (5-HT and 5-HTP) on pineal biochemical constituents of F. Pennanti
(1996) C. Haldar; R. Sarkar
In the pineal gland (PG) 5-hydroxytryptamine (5-HT) or serotonin is highly concentrated in comparison to other parts of the brain. It is the precursor of the formation of various hydroxy- and methoxyindoles whose reproductive effects are well known. However, the effect of serotonin on the PG itself is less extensively known. In the present experiment an attempt was made to study the effect of morning (0830-0930) injection of 5-HT (20 μg/day) and its intermediate product 5-hydroxytryptophan (5-HTP; 5 μg/day) on the biochemical constituents (protein, cholesterol and serotonin) of PG during the two phases of reproductive cycle (active/inactive) of Indian Palm Squirrel, Funambulus pennanti. The 5-hydroxyindoles suppressed the PG weight and its biochemical activities which initiated the unseasonal testicular recrudescence during reproductive inactive phase, whereas, no significant effect was noted on the pineal and testicular weight except the decrease in the serotonin content of PG during the reproductive active phase.
Effect of 5-methoxyindoles on testicular function of the Indian jungle bush quail Perdicula asiatica.
(1988) C. Haldar; M. Ghosh
Melatonin (aMT) implantation during testicular inactive phase (January-March) brought an early initiation of testicular development in Perdicula asiatica. However, during the recrudescence (March-May), active (April-June), and regressive (May-July-September) phases both aMT and 5-methoxytryptamine (MT) implantation had inhibited testicular weight and activity significantly. Subcutaneous injections of aMT, MT and 5-methoxytryptophol (ML) during morning (7.30 a.m.-8.00 a.m. and evening (4.30 p.m.-5.00 p.m.) could not bring about any significant effect on the weight or activity of the testes during the inactive (January-February) phase, while inhibited testicular weight and activity during the active (May-June) phase when administered in the morning as well as in the evening hours.
Effect of glucocorticoid and melatonin on immune function of an Indian tropical bird, Perdicula asiatica: An in Vivo and in Vitro study
(Biolife s.a.s., 2010) S.S. Singh; S.K. Yadav; C. Haldar
Inverse relationship between circulatory levels of glucocorticoids and melatonin has been reported for most of the vertebrates including human beings. We report the importance of glucocorticoid along with melatonin in avian immune regulation in an Indian tropical bird, Perdicula asiatica with in vivo and in vitro approach. Dexamethasone (30μg/bird/day) treatment of the male birds suppressed the immune activity as judged by the spleen activity (mass, anatomy), circulating total leukocyte, and lymphocyte count, blastogenic response, increased % apoptosis and cytokine (IL-2) production by splenocytes. Melatonin (25μg/100g B.wt./day) treatment increased the above-mentioned immune parameters whereas melatonin together with dexamethasone restored the suppressed immune parameters by dexamethasone to control level. In vitro melatonin (2.5 pM) supplementation to splenocyte cultures restored the dexamethasone (2 μM) suppressed splenocyte proliferation, % apoptosis and IL-2 production. Therefore, melatonin antagonized the suppressive effect of synthetic glucocorticoid on all immune parameters studied in vivo as well as in vitro. Furthermore, exogenous administration of dexamethasone and melatonin treatment altered the circulatory level of corticosterone and melatonin in an inverse manner. It is therefore, suggested that a hormonal trade-off between glucocorticoid and melatonin exists under in vivo and in vitro conditions, being involved in maintenance of the immune function of P. asiatica probably by involving cytokines i.e. IL-2 mediated pathway. Copyright © by Biolife, s.a.s.
Effect of melatonin and 5-methoxytryptamine administration on the testis and pineal gland activity of the fresh-water snake, Natrix piscator.
(1988) C. Haldar; R. Pandey
Effects of melatonin (aMT) and 5-methoxytryptamine (MT) were studied on the testicular activity cycle of the fresh-water snake, Natrix piscator. The subcutaneous implantation and the injections (morning as well as evening) of these two methoxyindoles prevented testicular recrudescence, retarded the testicular active phase, and accelerated the rate of regression of testes, while having no effect on the inactive testes. Contrary to this, these two compounds increased the pineal gland weight during different reproductive phases. These results revealed that both aMT and MT, whether they were continuously released through silastic capsule implants or administered through daily periodic injections, produced inhibitory effects on the testicular function.
Effect of pinealectomy and 5-methoxyindoles on testicular function in red headed buntings, Emberiza bruniceps
(1988) C. Haldar; M. Ghosh
[No abstract available]
Effect of pinealectomy and methoxyindoles on tyroid gland of water-snake Natrix piscator
(1989) C. Haldar; R. Pandey
[No abstract available]
Effect of pinealectomy and testosterone on gonadal regression and accessory sex organs in Indian palm squirrel, Funambulus pennanti
(1997) C. Haldar; S. Vidhu
Indian palm squirrel (Funambulus pennanti), is a tropical seasonal breeder presents a short gonadal regression period (October - November), concomitant with declining plasma testosterone level. If pinealectomized (Px), however, squirrels maintain full gonadal activity and plasma testosterone levels. The aim of the present study was, therefore, to determine if the Px and exogenous testosterone in intact and Px squirrels would prevent natural gonadal regression. Experiment was performed during testicular regression phase (i.e. August end to November) revealed that both the Px (60 days) and exogenous testosterone (100 μg/day/squirrel/30 days) prevented gonadal and accessory sex organ regression. This could be due to negative feedback by testosterone treatment which was more obvious in intact than the Px squirrels. A decline in day time plasma melatonin level after testosterone treatment was also indicative of inverse relationship between the gonadal and pineal hormones which in turn did not allow the collapse of accessory sex organs. Further, the pineal gland is under direct control of steroid hormones since receptors and aromatizing enzymes are noted in the same. Therefore, a pineal secreted melatonin stimulation of hypothalamic negative feedback centers for gonadal regression could be suggested in this tropical rodent as receptors for melatonin have been detected in above areas.