Ani Das, V; Remya, Robinson; Paulose, C S(Department of Bio Technology, January 23, 2006)
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Abstract:
Adrenergic stimulation has an inyortant role in the pancreatic It-cell proliferation and insulin secretion. In the present study. we
have investigaled how sympathetic system mgulales the panrrealic n I rnerui nr ht an:ilyiing I'pinephi inn 1111 ), Norepinephrinc
(NE) and /1-adrenergic receptor changes in the brain as (%eli is in the I swirls. Fill and NII showed a significant decrease in
the brain regions, pancreas and plasma :rt 72Ius iller partial prurcrealectonty. We observed an increase in the circulating insulin
levels at 72 hrs. Scatchard analysis using I CHI propranolol showed a significant increase in the number of loth the low affinity
and high affinity t-adrenergic receplors in cerebral cortex and hypothalamus of partially pancreatectornised rats during peak
DNA synthesis. The affinity of the receptors decrea,ed significantly in the low and high affinity receptors of cerebral cortex
and the high affinity hypothalamic receptors. In file brain stein, low affinity receptors were increased significantly during
regeneration whereas there was no change in the high affinity receptors. The pancreatic ff-adrenergic receptors were also up
regulated at 72 firs after partial panerealectony. In vitro studies showed that /i-adrenergic receptors are positive regulators of
islet cell proliferation and insulin secretion. Thus our results suggest that the t-adrenergic receptors are functionally enhanced
during pancreatic regeneration, which in turn increases pancreatic ft-cell proliferation an(hilisulin secretion in wean hug rats.
Biju,M P; Pyroja,Sulainian; Rajeshkumar,Neelimmathara V; Paulose,C S(Department of Biotechnology, February 15, 2001)
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Abstract:
Gamma aminohutyric acid (GAB A.) receptor tunctionaI status was artaIV se(l in pa It ial hcpatcctoIn ised.II'II). lead
nitrate (LN) induced hyperplastic and N-nifrosodiethylantinc INDEAI treated nctplastic rat Iivers during peak DNA
synthesis. The high-affinity I'HJGALA binding significantly decreased in PII and NDEi\ rats and the receptor affinity
decreased in NDEA and increased in LN rats compared with control . in NDEA. displacement analysis of I'I IIGABA
with muscimol showed loss of low-allinity site and a shill of high-allinity cite towards low-allinity . ' 1 he affinity sites
shifted towards high-affinity in LN rats. 'file number of low-allinity 1'I Ilhicuc)lline receptors decreased cignilic:uttly
in NDEA and I'll whereas it increased in LN rats. (ir\Bi\t receptor :gunist. unrscinrul. disc dependcnllyinhihilcd
epidermal growth factor IEGI--) induced DNA synthesis :uul enhanced the tr:utsfnrnting grmvth )actor (Il I I'(il (tlI
mediated DNA synthesis suppression in prim:uy hepalucvte cultures . Our results suggest that GABA,t reccjhtor act
as an inhibitory signal fur hepatic cell prolifctatiun.
An experiment was designed to assess the occurrence of multiple antibiotic resistances in
Vibrio sp from different (brackish and marine) environments. Water samples front nine marine landing
sites and two coastal inland aquaculture farms were screened for the Vibrio spp and assessed their
resistance to twenty-two different antibiotics, which arc commonly encountered in the aquatic
ecosystem. Tissue samples (shrimp, mussel and sepia) were tested from the sampling site with highest
antibiotic resistance. Of' the total 119 Vibrio isolates, 16. 8% were susceptible to all antibiotics. Of the
resistant (83.19%) Vibrio strains, 30.3% were resistant against three antibiotics, 55.5% were resistant
against 4-10 antibiotics, 14.14% were resistant against more than 10 antibiotics and 54% have shown
multiple antibiotics resistance (MAR). Antibiotic resistance index was higher in Coastal 3, 6, Aqua
farm 2 in isolates from water samples and all the tissues tested. Interestingly, incidence of antibiotic
resistance in isolates from water samples was comparatively lower in aquaculture farms than that
observed in coastal areas. Highest incidence of antibiotic resistance was evident against Amoxycillin,
Ampicillin, Carbencillin and Cefuroxime followed by Rilanipicin and Streptomycin and lowest against
Chloramphenicol, Tetracycline, Chlortetracycline, Furazolidone, Nalidixic acid, Gentamycin
Sulphafurazole, Trimcthoprinr, Neomycin and Amikacin irrespective of the sampling sites. Results
from various tissue samples collected from the sites of highest antibiotic resistance indicated that
antibiotic resistance Vibrio spp collected from fish and tissue samples were higher than that of water
samples. Overall results indicated that persistent use of antibiotics against diseases in human beings
and other life forms may pollute the aquatic system and their impact on developing antibiotic resistant
Vibrio sp may be a serious threat in addition to the use of antibiotics in aquaculture farms.
Ani Das, V; Savitha, B; Paulose, C S(Department of Biotechnology, April 4, 2006)
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Abstract:
purpose of this study was to investigate the
role of brain al-adrenergic receptor binding in the rat model
of pancreatic regeneration using 60-70% pancre:dectorny.
The a, -adrenergic receptors kinetics was studied in the
cerebral cor:cx and brain stem of sham operated . 72 It pan-
crea(ectoinised and 7 days pancreatectomised rats. Scar
chard analysis with I `I I lprazocin in cerebral cartes and brain
stein showed a significant decrease (/' < 0.01). (P < 0.05)
in maximal binding ( 1),,,,,) with it significant decrease
(P < 0.001 ), ( P < 0.01) in the K,,in 72 It pancreatecto-
raised rats compared with sham , respectively . Competition
analysis in cerebral cortex and brain stem showed it shift in
affinity during pancreatic regeneration . The sympathetic
activity was decreased as indicated by the significantly de-
increased norepinephrine level in the plasma (P < 0.001),
cerebral cortex (P < 0.01) and brain stem (P < 0.001) of
72 h pancreatectomised rats compared to sham . Thus, from
our results it is suggested that the central a, -adrenergic
receptors have a functional role in the pancreatic regenera-
Lion mediated through the sympathetic pathway.
Renuka, T R; Remya, Robinson; Paulose, C S(Department of Biotechnology, November 2, 2005)
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Abstract:
Parasympathetic system plays an important
role in insulin secretion from the pancreas. Cholinergic
effect on pancreatic beta cells exerts primarily through
muscarinic receptors. In the present study we investigated
the specific role of muscarinic M1 and M3 receptors in
glucose induced insulin secretion from rat pancreatic islets
in vitro. The involvement of muscarinic receptors was
studied using the antagonist atropine. The role of muscarinic
MI and M3 receptor subtypes was studied using
subtype specific antagonists. Acetylcholine agonist, carbachol,
stimulated glucose induced insulin secretion at low
concentrations (10-8-10-5 M) with a maximum stimulation
at 10-7 M concentration. Carbachol-stimulated insulin
secretion was inhibited by atropine confirming the role of
muscarinic receptors in cholinergic induced insulin secretion.
Both M1 and M3 receptor antagonists blocked insulin
secretion induced by carbachol. The results show that M3
receptors are functionally more prominent at 20 mM glucose
concentration when compared to MI receptors. Our
studies suggest that muscarinic M1 and M3 receptors
function differentially regulate glucose induced insulin
secretion, which has clinical significance in glucose
homeostasis.
Eswar Shankar,P N; Anu,Joseph; Paulose,C S(Department of Biotechnology, May 17, 2006)
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Abstract:
In the present study dopamine was measured in the hypothalamus, brainstem, pancreatic islets and plasma, using HPLC. Dopamine D2 receptor
changes in the hypothalamus, brainstem and pancreatic islets were studied using [3H] YM-09151-2 in streptozotocin-induced diabetic and insulintreated
diabetic rats. There was a significant decrease in dopatnine content in the hypothalamus (P<0.001), brainstem (P<0.001), pancreatic islets
(P<0.001) and plasma (P<0.00I) in diabetic rats when compared to control. Scatchard analysis of [3H] YM-09151-2 in the hypothalamus of
diabetic rats showed a significant decrease in Bax (P<0.001) and Kd, showing an increased affinity of D2 receptors when compared to control.
Insulin treatment did not completely reverse the changes that occurred during diabetes. There was a significant decrease in B,nax (P<0.01) with
decreased affinity in the brainstem of diabetic rats. The islet membrane preparation of diabetic rats showed a significant decrease (P<0.001) in the
binding of [3H] YM-09 151-2 with decreased Kd (P<0.001) compared to control. The increase in affinity of D2 receptors in hypothalamus and
pancreatic islets and the decreased affinity in brainstem were confirmed by competition analysis. Thus our results suggest that the decreased
dopamine D, receptor function in the hypothalamus, brainstem and pancreas affects insulin secretion in diabetic rats, which has immense clinical
relevance to the management of diabetes.