NISCAIR Online Periodicals Repository Collection: IJEB Vol.44(08) [August 2006]

Does melatonin have a time-dependent effect on brain and gill ionic metabolism in a teleost, Anabas testudineus (Bloch)?

Sat, 29 Jul 2006 22:58:59 GMT

Title: Does melatonin have a time-dependent effect on brain and gill ionic metabolism in a teleost, Anabas testudineus (Bloch)?

Authors: Divya, L; Vijayasree, A S; Sreejith, P; Beyo, R S; Smita, M; Oommen, O V

Abstract: Exogenous administration of 0.20, 0.40 and 0.60 μg/g body weight melatonin over a 24 hr cycle caused an inhibition of Na⁺, K⁺ ATPase activity in both brain and gills of A. testudineus. However, Ca²⁺ ATPase activity in the brain was significantly inhibited by the highest dose, and that in the gill at all the doses of melatonin. Evening injection of melatonin had an inhibitory effect on both brain and gill Na⁺K⁺ and Ca²⁺ ATPase activity. Melatonin treatment in the morning for 12 hrs did not have an effect on brain Na⁺, K⁺ ATPase, while Ca²⁺ ATPase was inhibited. Similar treatment stimulated Na⁺, K⁺ and Ca²⁺ ATPase activity in the gills. Sodium, potassium and calcium ions in the gill were significantly reduced in the evening treated group while no change was observed in the morning melatonin injected group. The results suggest that melatonin elicits a time - dependent effect on the enzymes and ionic content in the brain and gills of A. testudineus.

Page(s): 635-639

Tri-iodo thyronine regulates antioxidant enzyme activities in different cell fractions through a mechanism sensitive to actinomycin D in a teleost, Anabas testudineus (Bloch)

Sat, 29 Jul 2006 22:58:59 GMT

Title: Tri-iodo thyronine regulates antioxidant enzyme activities in different cell fractions through a mechanism sensitive to actinomycin D in a teleost, Anabas testudineus (Bloch)

Authors: Saumya, S M; Sreejith, P; Vijayasree, A S; Divya, L; Manju, M; Oommen, O V

Abstract: The present study evaluated the effects of hyperthyroid state on lipid peroxidation and antioxidant enzymes in the crude (CF), post nuclear (PNF) and mitochondrial fractions (MF) of the fish liver. The in vivo injection of T₃ (200ng) did not change the lipid peroxidation products, malondialdehyde (MDA) and conjugated dienes (CD), while actinomycin D (10mg), a potent mRNA inhibitor when administered with T₃ increased them. The antioxidant enzymes like superoxide dismutase (SOD) and catalase (CAT), glutathione peroxidase (GPx) and glutathione reductase (GR) had an increased activity in CF and MF of hyperthyroid group to compete the increased oxidative stress, but actinomycin D partially inhibited the T₃‑ induced activity. SOD and CAT activities in PNF of hyperthyroid group had no change, the glutathione concentration varied depending on the GPx and GR activity. Hyperthyroidism decreased the protein content, while simultaneous administration of actinomycin D inhibited the T₃ action of elevating the protein content. The results suggest that the antioxidant defense status in A. testudineus is modulated by thyroid hormone, through an action sensitive to actinomycin D.

Page(s): 640-646

Modulation of gastric mucosal mast cell population : Role of vestibulo cerebellar lesion

Sat, 29 Jul 2006 22:58:59 GMT

Title: Modulation of gastric mucosal mast cell population : Role of vestibulo cerebellar lesion

Authors: Sarkar, Nita; Purkayastha, Sudarshana; Sarkar, Biswarup; Guha, Debjani

Abstract: Posterior cerebellar lesion induced severe focal inflammatory ulcers at the stomach associated with extensive damage of the surface epithelial cells, leading to focal necrotic ulcers. The ulcer index increased maximally and progressively between day 7 and day 14 after lesion. The total mucosal mast cell and degranulated mucosal mast cell increased maximally on day 7 and progressively declined from day 14 to day 21. Gastric histamine content was also significantly increased on day 7 and 14. A significant reduction in mucous content (total CHO:P) was observed within 7-28 days after lesion. The results suggest that the gastric mucosal mast cells play an important role in ulcerogenesis induced by cerebellar lesion.

Page(s): 627-634

Fishmeal extract bile salt lactose agar–A differential medium for enteric bacteria

Sat, 29 Jul 2006 22:58:59 GMT

Title: Fishmeal extract bile salt lactose agar–A differential medium for enteric bacteria

Authors: Subbannayya, K; Udayalaxmi, J; Anugraha, M

Abstract: Fishmeal extract bile salt lactose agar (FEBLA), a new differential medium for enteric bacteria was developed and evaluated for its ability to grow and differentiate lactose fermenters (LF) from non-lactose fermenters (NLF) in comparison with MacConkeys agar. Performance of FEBLA was at par with the latter. On FEBLA medium, the contrast between LF and NLF colonies was pronounced and Klebsiella pneumoniae produced more mucoid colonies than on MacConkeys agar (Hi Media). Unlike MacConkeys agar, a 24 h culture of K. pneumoniae cells on FEBLA were longer and thicker with abundant capsular material around the bacilli. Escherichia coli produced long and thick cells but only after 48h. No change in cell morphology was evident with regard to Salmonella typhi, S. paratyphi A, Shigella flexneri, Pseudomonas aeruginosa, Proteus mirabilis, Proteus vulgaris, Citrobacter koseri and Acinetobacter baumannii. Performance of the medium was controlled using E. coli and S. flexneri. FEBLA is simple, cost effective and may be a suitable alternative in the preliminary identification of enteric bacteria.

Page(s): 675-678