Calcium binding in plasma during high antidiuretic hormone-like activity in vivo.
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Biomedical subjects
Publications and source records attributed to G S Gupta.
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Gamma-HCH (lindane) administered for long durations is reported to cause toxic cardiovascular effects. Present study was carried out to assess the changes in cardiovascular activity and cellular calcium homeostatic mechanisms in rats administered 3 mg kg-1 day-1 of gamma-HCH p.o. for 6 weeks. The changes in electrocardiogram were marked by a decrease in R-R interval and the amplitude of the P wave by 53% and 50%, respectively. The amplitude of R and T waves was increased by 65% and 58%, respectively. Calcium-45 influx was increased in atrial trabeculae (33%) and in papillary muscle (10%). The plasma calcium concentration was increased (32%) and Ca,K-ATPase activity in heart was decreased (50%). It is suggested on the basis of these findings that cellular calcium homeostatic mechanisms are involved in the cardiovascular effects of gamma-HCH administered chronically in rats.
The present study was carried out to find the effects of Pb acetate (10-50 mg/kg body wt) after oral administration on: 1. The distribution of elements, such as Fe, Cu, Zn, and Mn; 2. The activity of 6-amino levulenic acid dehydratase (delta-ALAD) and alkaline phosphatase (PAP); and 3. On the level of reduced glutathione (GSH) in murine placenta. Pb toxicity expressed on a dry-wt basis was reflected in terms of deficiency of delta-ALAD and PAP and enhanced content of GSH. Analysis of trace elements following Pb exposure showed low levels of Mn and Cu. Although Fe composition of placenta remained within normal range with increasing load of endogeneous Pb, Zn decline was not consistent after oral feeding of Pb acetate. Deficiency of PAP after Pb exposure did not correlate with the endogeneous levels of Pb or Zn therein, but correlated with endogeneous levels of Mn. Placental deficiencies of Cu and Mn have been related to the disturbed placental functions by Pb accumulation.
Formation of lipid peroxides in vitro was investigated in the lung, liver, and brain homogenates of normal male rats. Unlike brain tissue, increasing the concentration of lung or liver in homogenates resulted in decreased output of lipid peroxides. Further, lung homogenates exerted an inhibition of lipid peroxide formation by brain and dilute liver homogenates. The factor responsible for such inhibition was located in the postmitochondrial supernatant, was heat stable, nondialysable, could be preserved in frozen state for 60 days, concentrated by dialysis against powdered sucrose, and precipitated by ammonium sulphate.
The effect of coal-quartz mixtures that contained graded amounts of coal or quartz was studied using peritoneal macrophage cultures and plasma-free washed sheep erythrocyte suspensions. A stoichiometric relationship was observed between the quartz content of coal-quartz mixture and the amount of lactic dehydrogenase liberated extracellularly and acid dye uptake by macrophage monolayers. Total lactic dehydrogenase of the monolayers plus supernatant remained unaltered following exposure to different dust mixtures. Dusts containing a higher concentration of quartz also produced a greater degree of hemolysis. Coal did not inhibit the quartz-induced macrophage cytotoxicity or erythrocyte hemolysis.
Acid phosphatase of human seminal plasma is inhibited in presence of normal rabbit serum involving non-competitive mechanism whereas this character is normalized and activity is stabilized in presence of its rabbit antiserum. Kinetic studies on stabilization of acid phosphatase by antiserum were combined by L-tartrate, a specific inhibitor of prostatic acid phosphatase. L-tartrate, a specific inhibitor of prostatic acid phosphatase. L-tartrate inhibited the enzyme in presence and absence of normal and antiserum by competitive mechanism and percentage of inhibition of L-tartrate was involve in the binding with acid phosphatase antibodies. The kinetics of heat denaturation of acid phosphatase suggested that seminal acid phosphatase is more heat labile in presence and absence of normal serum than in presence of antiserum. The temperature of denaturation corresponding to half the initial activity(T 1/2) in presence of normal and antisera were 34 degrees and 66 degrees C respectively. NOn-linearity of Arrhenius plots for denaturation rates of the enzyme suggested various conformational states for denaturation yielding Ea varying between 20.08 and 5.03 Kcals at 25-65 degrees C.
Beta-glucuronidase (beta-glucuronidase) in human seminal plasma consists of two forms of isozymes (major and minor forms). Antiserum prepared against the purified major form of beta-glucuronidase in rabbits was used for studies of immunological specificity and immunohistochemical localization of beta-glucuronidase in the human male reproductive tract. By ouchterlony immunodiffusion technique, anti-beta-glucuronidase serum showed reaction of identity with human tissue extracts such as liver, spleen, lungs, testis, epididymis, prostate, and seminal vesicles. Though monkey testis and epididymis extracts completely reacted with human seminal beta-glucuronidase antiserum, no cross-reaction was observed with mouse and rat tissue extracts. Immunofluorescent studies revealed that beta-glucuronidase is localized in the early stages of spermatogenesis in testis, in columnar cells of the epididymis, and in glandular cells of the prostate and seminal vesicles. Consistent absence of fluorescence in the lumens of testis and epididymis as well as negative cross-reaction between antiserum and sperm extracts suggested that major form of beta-glucuronidase in human seminal plasma is not immunologically identical with human spermatozoa. It is concluded that major form of beta-glucuronidase in seminal plasma is not tissue-specific although it appears to have limited species specificity.
Placental extracts obtained from CBA (H-2k) mice during syngeneic (CBA female X CBA male) pregnancy were evaluated for their capacity to deviate the immune reaction of CBA mice toward A/J(H-2a) immunizing spleen cells, as tested by alloantibody subclass formation and Sa 1 allograft accelerated rejection-or enhancement. The immunomodulatory activity appeared to be located in the soluble and in the insoluble extracts of placenta. The sodium deoxycholate (SDO) solubilized proteinic material, fractionated on Concanavalin A [Con A] and injected to CBA mice simultaneously with A/J spleen cells caused a suppression of the hemagglutinating titer and C-mediated cytotoxicity (IgG2). However, it also favoured antibody-mediated mast cell degranulation (IgG1) and Sa 1 allograft enhancement. The presence and role of IgG1 antibodies in both tumor enhancement and gestation has been described. It is concluded that placenta contains Con A-binding glycoproteins which are located in the membranes and released in soluble form. They exert their immunomodulatory effect in a way which might help the successful outcome of pregnancy as it helps to enhance the development of allografted sarcoma.
Studies were carried out to further localize pulmonary tissue lipid peroxidation inhibitor reported earlier to be present in whole lung homogenate in rat. A major portion of the inhibitory material could be lavaged from bronchoalveolar region using various wash media. The material was heat labile and exhibited higher degree of inhibition when recovered from the lungs of mature and aged rats.
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