Saumen Kumar Maitra

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The present communication is an attempt to demonstrate the influence of melatonin on the action of maturation inducing hormone (MIH) on the maturation of oocytes in carps. The oocytes from gravid female major carp Labeo rohita were isolated and incubated separately in Medium 199 containing (a) only MIH (1 microg/ml), (b) only melatonin (at concentrations of(More)
Melatonin (N-acetyl-5-methoxytryptamine) was first purified and characterized from the bovine pineal gland extract by Aron Lerner and co-workers in 1958. Since then, a plethora of information has piled up on its biosynthesis, metabolism, time-bound periodicity, physiological and patho-physiological functions, as well as its interactions with other endocrine(More)
The influences of serotonin (5-hydroxytryptamine) on the action of melatonin (N-acetyl-5-methoxytryptamine) in MIH (maturation inducing hormone)-induced meiotic resumption were evaluated in the oocytes of carp Catla catla using an in vitro model. Oocytes from gravid female carp were isolated and incubated separately in Medium 199 containing either (a) only(More)
Isotopic and non-isotopic immunoassays of hCG, based on the principle of competitive inhibition, using micro-well as solid support and 125I and biotin as labels for hCG, have been developed. In both the assays, rabbit polyclonal antibody was immobilized onto micro-wells. In the non-isotopic assay, to the hCG antibody coated micro-wells, 50 microL of(More)
Adult male whitethroated munias, Lonchura malabarica (Aves; Passeriformes), were orally administered with methyl parathion (O, O-dimethyl O-(4-nitrophenyl) phosphorothioate), an extensively used organophosphate pesticide, in graded sublethal dose (5 micro g-, or 10 micro g-, or 20 micro g/100 g body wt/day) for variable durations (1-, 5-, or 10 day/s)(More)
The structure of the pineal complex and the annual reproductive cycle in a major Indian carp, Catla catla, were investigated in the present study. Additionally, given the well-known inhibitory effects of the pineal on reproductive function in mammals, attempts were made to investigate whether or not the pineal exerts an inhibitory influence on reproductive(More)
In the rat pineal gland N-acetyltransferase (NAT) activity and synaptic ribbon (SR) numbers display a circadian rhythm. It is well-known that NAT activity is regulated by adrenergic mechanisms involving cyclic adenosine monophosphate (cAMP) as a second messenger. However, the mechanism involved in the regulation of SR numbers has not been established so(More)
The major carp Catla catla is a popular freshwater edible fish and an extensively cultured species in India. However, basic information on the physiology of reproduction is lacking in this species. By virtue of its surface feeding habit, it maintains close contact with environmental light, and is a species of choice for the study of temporal organization of(More)
Importance of melatonin (N-acetyl-5-methoxytryptamine) in the regulation of oocyte maturation has been studied in a carp Catla catla. Melatonin secretory cells were immunocytochemically localized only in the end vesicle. Diurnal and seasonal studies indicated that the serum levels of melatonin exhibit a minimum diurnal value in the mid-day of all seasons,(More)
In this report, we have examined the effects of lithium on testicular morphology in a male subtropical wild avian species, the roseringed parakeet (Psittacula krameri). Adult male birds were collected during the months of February-March, a time when the testicular gametogenic activity in these seasonally breeding birds is at its peak. They were injected,(More)