28 research outputs found
Catalase in Testes and Epididymidis of Wistar Rats Fed Zinc Deficient Diet
Catalase activities have been evaluated in testes and caput and cauda epididymis of Wistar rats fed on zinc deficient diet for 2 and 4 weeks. The enzyme activity has been measured as chromic acetate formed by heating of dichromate (in acetic acid) in presence of H2 O2 with perchromic acid as an unstable intermediate. Observed non-significant increase in catalase activity in testes as well as in caput and cauda epididymis of 2 weeks experiments has been related to low levels of H2 O2 produced in two organs whereas significant (P<0.01/0.001) increase in catalase activity in 4-weeks experiments indicate for increased oxidative stress due to phagocytotic activity of Sertoli cells in testes and damaged spermatozoa in epididymis. Thus, zinc deficiency increases catalase activity in testes and epididymis
Short-term zinc deficiency in diet induces increased oxidative stress in testes and epididymis of rats
786-794In order to determine the effects of Zinc
deficient diet on oxidative stress in testis and epididymis, various parameters
viz: total proteins, lipid peroxidation, hydroperoxides, antioxidant capacity and
enzymatic activities are evaluated in rats fed on zinc deficient diet for 2, 4
and 6 weeks. Total proteins, water and lipid solouble antioxidant capacity
decreased while lipid peroxidation (TBARS) and hydroperoxides concentration
increased in testes, caput and cauda epididymis except in 2ZD (testes) where
hydroperoxides revealed a significant decrease. GSH decreased in testes and
caput and cauda epididymis. GPx and γ-GT activities increased in testes and
caput and cauda epididymis of zinc deficient rats. Further, GST increased in
testes but exhibited decreases after 2 and 4 weeks and an increase after 6
weeks in caput and cauda epididymis of zinc deficient rats. GR activities
decreased in testes but it increased in caput and cauda epididymis of zinc
deficient rats. Thus, zinc deprivation results in increased sensitivity to oxidative
stress. All these may have been as a consequence of increased ROS generation
and/or decreased zinc dependent antioxidant processes
Metallothionein in male reproductive organs of adrenalectomized and hydrocortisone-treated Wistar rats
288-291Adrenalectomy resulted in an increase in
metallothionein (MT) levels in testes, caput and cauda epididymis and prostate
of rats but not in seminal vesicles where its levels decreased significantly. Inspite
of administration of hydrocortisone, MT in testes, prostate (1.2 mg), caput (0.3
mg days 2, 8; 0.6 mg and 1.2 mg) and seminal vesicles (0.3 mg day 2, 4; 0.6 mg
and 1.2 mg) remained increased. Thus adrenal insufficiency/hydrocortisone has
no direct influence on MT levels. However, the increased levels of MT can be
related to its ability to protect the cells from free radical damage caused by atrophy
of reproductive tissues in adrenalectomised rats. Exogenously administered hydrocortisone
to ADX rats resulted
in return to ADX state as hydrocortisone
metabolizes (half-life < 12 hr) and hence MT levels remained increased. The observations
could provide a clue for the physiological functioning of the male reproductive
tissue in a state of adrenal deprivation and hormonal supplementation
Testicular protein profile (SDS-PAGE) study of zinc deficient Wistar albino rat
27-34Present study has revealed that zinc plays important role in regulating the production and secretion of proteins at transcriptional or translational level. Study has firmly depicted the change in the levels of polypeptide of 70 kDa in zinc deficient group. The protein pattern in pair fed group has been affected mainly to combat the insult due to low food intake
SDS-PAGE analysis of caput epididymis proteins in rats receiving a zinc deficient diet
1104-1110Caput epididymis proteins from control, pairfed
and zinc deficient (ZD) wistar weanling albino rats after 2-, 4-, 6- and 8-weeks
were examined using SDS-PAGE followed by densitometric scanning of the gels. In
comparison to the control and pairfed rats, ZD rats displayed new proteins. These
included a Mr 42 kDa from 2ZD, Mr 47.5, 27.5, 23.2 and 16.0 kDa from 4ZD and Mr
87 and 14.2 kDa from 6ZD group. The 8ZD group, however, revealed no additional protein
bands over controls. Further, several other proteins were missing from ZD rats.
These included Mr 93 and 71 kDa from 2ZD; 93, 90, 79, 67, 62, 55 and 15.3 kDa from
4ZD; 60, 45.5, 34, 30 and 24 kDa from 6ZD and 41.5, 33 and 27.5 kDa bands from 8ZD
group. The results indicate that the induced Zn-deficient state may be responsible
for the altered protein patterns in the caput epididymis. The duration of low Zn
uptake period also appears to influence the protein pattern in caput epididymis
Effect of dietary zinc deficiency on metallothionein concentration of epididymal luminal fluids of weanling Wistar albino rats
118-122Metallothionein
(MT) and zinc concentrations have been estimated in luminal fluids of caput/corpus
and cauda epididymis and serum of zinc deficient (ZD), pairfed (PF) and control-ad
libitum fed (ZC) groups of Wistar rats. MT decreased significantly
in luminal fluids of caput corpus and cauda epididymis and serum of zinc
deficient rats as compared to their respective controls. However, the decrease was
non-significant in luminal fluids of corpus epididymis and serum of 4-weeks zinc
deficient animals as compared to their control. Zinc levels also declined significantly
in luminal fluids of epididymis
and serum of zinc deficient
rats as compared to their respective pairfed and control groups. Thus zinc deficiency
state reduces zinc and MT concentrations in luminal fluid of epididymis and
serum.</span
Cloning and characterization of GTP-binding proteins of Mycobacterium tuberculosis H<SUB>37</SUB>Rv
GTP-binding proteins (G-proteins) are highly conserved signaling molecules that participate in cellular signaling and bacterial pathogenesis by regulating the activity of cognate GTPases. However, the exact role of G-proteins in the pathogenesis of mycobacterium tuberculosis is poorly understood. The complete genome sequence of M. tuberculosis H<SUB>37</SUB>Rv, suggests the presence of several homologs of bacterial G-proteins. In the present study, three G-proteins, Era, Obg and LepA of M. tuberculosis H<SUB>37</SUB>Rv were cloned and expressed in Escherichia coli. Purified proteins showed GTP-binding and hydrolyzing activities. A point mutation in the conserved GTP-binding motif, AspXXGly (Asp to Ala) in Era (Asp-258) and Obg (Asp-212) proteins resulted in the loss of the associated activities, confirming that known key residues in well-established G-proteins are also conserved in mycobacterial homologs. This study confirms that Era, Obg and LepA of M. tuberculosis H<SUB>37</SUB>Rv possess GTPase activity and provide a platform to understand the physiological significance of these proteins in associated pathogenesis
Nucleoside diphosphate kinase-like activity in adenylate kinase of Mycobacterium tuberculosis
Ak (adenylate kinase) is a ubiquitous enzyme that catalyses a reversible high-energy phosphoryl-transfer reaction between ATP and AMP to form ADP. In the present study, the Ak gene (adk) of mycobacterium tuberculosis was cloned, expressed in escherichia coli and purified as a glutathione S-transferase fusion protein. Purified Ak converted AMP into ADP in the presence of [γ -32P]ATP or [γ -32P]GTP. Replacement of arginine-88 of adk with glycine resulted in the loss of enzymic activity. The purified protein also showed Ndk (nucleoside diphosphate kinase)-like activity as it transferred terminal phosphate from [γ-32P]ATP to all nucleoside diphosphates, converting them into corresponding triphosphates. However, Ndk-like activity of Ak was not observed with [γ-32P]GTP. Immunoblot analysis of various cellular fractions of M. tuberculosis H37Rv revealed that Ak is a cytoplasmic protein. The dual activity of Ak as both nucleoside mono- and di-phosphate kinases suggested that this enzyme may have a role in RNA and DNA biosynthesis in addition to its role in intracellular nucleotide metabolism
Comparative study of three different mycobacterial antigens with a novel lipopolysaccharide antigen for the serodiagnosis of tuberculosis
Demonstration of Mycobacterium tuberculosis in a smear or culture is the most reliable method for diagnosing tuberculosis (TB). In the last 10 years, several enzyme-linked immunosorbent assays (ELISAs) based on mycobacterial antigens (such as antigen 60, 38 kDa antigen, and antigen Kp90) have been used for the rapid diagnosis of TB. In this study, we report the isolation of an immunodominant lipopolysaccharide (LPS) antigen from M. tuberculosis H37Rv, which can be used for the serodiagnosis of TB. The LPS antigen was compared with three commercially available mycobacterium-specific antigens for the detection of TB. The antigens were evaluated using serum samples obtained from 59 Indian patients (19 patients with active pulmonary TB, 20 with extrapulmonary TB, and 20 with nontuberculous pulmonary disease) and 20 healthy adults. Antigen 60 IgG (sensitivity 89%, specificity 97%) and LPS (sensitivity 84%, specificity 97%) were more sensitive and specific than 38 kDa antigen IgG (sensitivity 79%, specificity 97%) and Kp90 IgA (sensitivity 82%, specificity 40%). These results indicate that the LPS antigen can be used as a sensitive tool for the serodiagnosis of TB and could be utilized to develop an ELISA for the screening of patients for TB