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Amul Sakharkar Praful Singru Nishikant Subhedar 《Fish physiology and biochemistry》2005,31(2-3):163-166
We studied GnRH immunoreactivity in the pineal gland of the Indian major carp Cirrhinus mrigala during different phases of reproductive cycle. In the resting phase (December–January), GnRH immunoreactive (-ir) fibers
were organized as paired fascicles above the posterior commissure that ascend in the stalk and distribute widely in the pineal
gland. The GnRH-ir fiber density significantly declined (P<0.001) during the preparatory phase (February–April) and the fibers disappeared thereafter. While no GnRH fibers were seen
during the prespawning (May–June) and spawning (July–August), isolated GnRH-ir fibers reappeared in the postspawning phase.
Since no GnRH cell bodies were detected in the pineal, these GnRH-ir fibers seem to be of central origin. The results reveal
a distinct reciprocal relationship between the GnRH immunoreactivity in the pineal and the status of the ovarian maturity;
the fibers appeared in the pineal only during the period of ovarian quiescence. While the functional significance of these
cyclic changes in GnRH is yet to be determined, we suggest that the decapeptide may serve as a transmitter of central origin
that modulates the activity of the pineal gland. 相似文献
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Praful S. Singru Amul J. Sakharkar Minakshi Mazumdar Nishikant Subhedar 《Fish physiology and biochemistry》2007,33(4):297-309
Ultrastructural localization of neuronal nitric oxide synthase (nNOS) in olfactory receptor neurons (ORNs) and immunohistochemical
detection of the enzyme in forebrain, pituitary, and pineal were undertaken in the teleost Oreochromis mossambicus. Application of post-embedding immunoelectron microscopy revealed nNOS-labeled gold particles on the cilia, microvilli, mitochondria,
and Golgi complex of the ORNs. Gold particles were also seen adhered to microtubules in the axons that extend to the olfactory
nerve layer in the olfactory bulb. With light microscopy, nNOS-immunoreactive neurons were seen in preoptic area, nucleus
entopeduncularis, and parvocellular, and magnocellular subdivisions of nucleus preopticus (NPO). Numerous cerebrospinal fluid-contacting
cells lining the wall of the third ventricle at the level of the NPO showed intense immunoreactivity. Intense to moderate
immunoreactivity was observed in the neurons of suprachiasmatic nucleus, nucleus lateralis tuberis pars lateralis, and nucleus
recessus lateralis. While several immunoreactive fibers were detected in medial olfactory tract, suprachiasmatic area, and
hypothalamo-hypophyseal tract, a few were seen throughout the telencephalon, in the optic chiasma, tuberal area, and inferior
lobes. In the pituitary, nNOS-containing fibers were seen in the neurohypophysis, rostral pars distalis, proximal pars distalis,
and pars intermedia. While intense immunoreactivity was noticed in some cells in the pineal, immunoreactive fibers were detected
in the pineal stalk as well as parenchyma. We suggest that nitric oxide may play a role in processing olfactory and photic
information, circadian rhythms, and neuroendocrine regulation in tilapia. 相似文献
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The effects of aqueous extracts of Celastrus paniculatus (CP) seeds were shown to have antioxidant properties in rats. In the study reported here, we have investigated the free radical scavenging capacity of three aqueous extracts (WSEs) obtained from CP seeds: a room temperature extract (WF); a hot water extract (HF); an acid extract (AF). All the WSEs exhibited a dose-dependent free radical scavenging capacity for 1,1-diphenyl-2-picryl-hydrazyl radical (DPPH) and also for superoxide-generated assays (in vitro assays). In addition, we used enriched forebrain primary neuronal cell (FBNC) cultures to evaluate the neuroprotective effects of the three CP-WSE extracts on H(2)O(2)-induced toxicity. FBNC were pre-treated with the CP-WSE and then with H(2)O(2) to evaluate the protection afforded against H(2)O(2)-induced toxicity. The criteria for neuroprotection by the WSEs were based on a mitochondrial function test following the H(2)O(2)-induced neurotoxicity. All the WSEs significantly attenuated H(2)O(2)-induced neuronal death, and AF was the most effective in protecting the neuronal cells against oxidative injury caused by H(2)O(2). In 10 day FBNC, cellular superoxide dismutase activity was not affected by the WSEs or H(2)O(2), but catalase activity was decreased and levels of malondialdehyde were increased by H(2)O(2) treatment. When the neuronal cells were treated with WSEs prior to H(2)O(2) exposure, catalase activity was increased and levels of malondialdehyde were decreased significantly. The data presented here suggest that CP seed WSEs protected neuronal cells in part by their free radical scavenging properties, by reducing lipid peroxidation, and also by their ability to induce the antioxidant enzyme catalase. Our results indicate that WSEs might exert neuroprotective effects against increased oxidative stress resulting from free radical damage that is associated with a number of neurodegenerative diseases. 相似文献
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Minakshi Mazumdar Praful Singru Amul Sakharkar Makrand Deshmukh Nishikant Subhedar 《Fish physiology and biochemistry》2005,31(2-3):173-176
Glucagon-like peptide-1-immunoreactivity (GLP-ir) was seen in several olfactory receptor neurons in the olfactory epithelium
and in the olfactory nerve fascicles that extend caudally to the bulb and innervate the glomerular layer. Thick GLP-ir fascicles
were seen in the medial olfactory tracts (MOT); these probably represent the extrabulbar olfactory projections. GLP-ir fibers
in the MOT penetrate into the telencephalon, swing dorsocaudally into the area ventralis telencephali/pars supracommissuralis
(Vs) just above the anterior commissure. The immunoreactive fascicles continue caudally in the dorsal hypothalamus and are
traceable as far as the lateral recesses. Scattered GLP-ir fibers were seen in the ventral telencephalon and preoptic area.
While several immunoreactive cells were seen in the pars intermedia of the pituitary gland, few were encountered in the rostral
pars distalis and proximal pars distalis. Role for the peptide in the processing of olfactory information and in the regulation
of pituitary gland may be suggested. 相似文献
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