Effect of age, weight and adequacy of zinc intake on the balance between alkaline ribonuclease and ribonuclease inhibitor in various tissues of the rat

1978 ◽  
Vol 39 (2) ◽  
pp. 375-382 ◽  
Author(s):  
J. K. Chesters ◽  
Marie Will
Keyword(s):  
Ribonuclease Activity ◽  
Zn Deficiency ◽  
Ribonuclease Inhibitor ◽  
Zinc Intake ◽  
Zn Concentration ◽  
Tissue Homogenates ◽  
Alkaline Ribonuclease ◽  
Natural Inhibitor ◽  
Effect Of Age

1. Deficiency of zinc inhibits growth and also increases the activity of alkaline ribonuclease in certain tissues of the rat (Prasad & Oberleas, 1973). Zn could influence ribonuclease activity by direct effects on the enzyme or its natural inhibitor, or non-specifically as occurs when growth rate is affected by various other factors. These possibilities were studied.2. Alkaline ribonuclease was shown to be inhibited by Zn in vitro, but the concentrations of Zn required were so high that the enzyme was probably not directly affected by changes in tissue Zn concentration caused by dietary deficiency.3. At lower concentrations, Zn added in vitro increased the activity of alkaline ribonuclease in tissue homogenates probably by inactivating the inhibitor of the enzyme.4. Age, weight and particularly food restriction caused tissue-specific alterations of ribonuclease and ribonuclease inhibitor concentrations in liver, kidney, oesophagus, testis and thymus.5. The ribonuclease activities in liver, kidney and testis of Zn-deficient rats were unaltered in comparison with those of pair-fed rats. In thymus, which decreased in weight in the Zn-deficient animals, there was a concomitant increase in ribonuclease activity, but in oesophagus, the deficiency reduced the activity of ribonuclease.6. The effects of Zn deficiency upon alkaline ribonuclease and its inhibitor are probably secondary consequences of reductions in food intake or growth.

Alkaline and Acid Ribonucleases of Kidney and Spleen of Nephrotic Rats

1971 ◽  
Vol 49 (5) ◽  
pp. 535-542 ◽  
Author(s):  
D. M. Nicholls ◽  
Edward S. Bishay
Keyword(s):  
Ribonuclease Activity ◽  
Ribonuclease Inhibitor ◽  
Inhibitor Activity ◽  
Alkaline Ribonuclease

Alkaline ribonuclease activity (pH 7.8) was markedly decreased in all the fractions of kidney homogenates from nephrotic rats compared to the fractions of kidney homogenates from control rats. In contrast to the active alkaline ribonuclease activity at pH 7.8, the latent alkaline ribonuclease activity at pH 7.8 was increased in fractions from homogenates of nephrotic kidney due to increased ribonuclease inhibitor activity. In liver from nephrotic rats, however, there was no decrease in pH 7.8 alkaline ribonuclease activity and no increase in alkaline ribonuclease inhibitor. Alkaline ribonuclease activity at pH 9.5 and acid ribonuclease activity (pH 5.8 and 4.8) were also decreased in fractions from homogenates of kidney from nephrotic rats but not to the same degree as pH 7.8 alkaline ribonuclease activity. In fractions from homogenates of spleen, only small changes in ribonuclease activity were noted in nephrotic rat preparations compared to control rat preparations.

The assessment of zinc status of an animal from the uptake of65Zn by the cells of whole blood in vitro

1978 ◽  
Vol 39 (2) ◽  
pp. 297-306 ◽  
Author(s):  
J. K. Chesters ◽  
Marie Will
Keyword(s):  
Alkaline Phosphatase ◽  
Whole Blood ◽  
Surgical Stress ◽  
Zn Deficiency ◽  
Zn Uptake ◽  
Zn Concentration ◽  
Plasma Alkaline Phosphatase ◽  
Zn Status ◽  
Dietary Deficiency

1.65Zn uptake by blood cells in vitro has been compared with plasma Zn concentration and plasma alkaline phosphatase (EC3.1.3.1) activity as indicators of an animal's Zn status.2. Dietary Zn deficiency, low food intake, reduced dietary protein content and endotoxin administration all reduced plasma Zn concentration in the rat. In each case there was a parallel reduction in plasma alkaline phosphatase activity and an increase in65Zn uptake in vitro by cells of whole blood.3. A similar relationship between the three measurements existed in sheep with lowered plasma Zn concentrations whether these were caused by dietary deficiency or by post-surgical stress.4.65Zn uptake by cells of whole blood did not differentiate dietary Zn deficiency from the other factors which reduce plasma Zn under ‘field’ conditions.5.65Zn uptake by the cells in whole blood in vitro was three to five times less rapid in blood of ruminant origin than in that from non-ruminants. This difference related to the erythrocytes rather than to the leukocytes or the plasma.

scholarly journals Zinc deficiency and the zinc requirements of calves and lambs

1967 ◽  
Vol 21 (3) ◽  
pp. 751-768 ◽  
Author(s):  
C. F. Mills ◽  
A. C. Dalgarno ◽  
R. B. Williams ◽  
J. Quarterman
Keyword(s):  
Weight Gain ◽  
Live Weight ◽  
Basal Diet ◽  
Zn Deficiency ◽  
Zinc Intake ◽  
Zn Concentration ◽  
Rapid Fall ◽  
Trace Element Deficiency ◽  
Diagnosis Of Zn Deficiency ◽  
Zn Availability

1. The effects of changes in zinc intake on weight gain, plasma Zn concentration and the development of clinical lesions of Zn deficiency have been studies in Zn depletion and repletion studies with calves and lambs.2. A basal diet, the principal components of which are urea, dried egg white, starch, glucose, cellulose and arachis oil has been developed for trace element deficiency studies with ruminants.3. Weight gain ceased abruptly in both calves and lambs when either the unsupplemented basal diet was given or when Zn supplements provided only 0.05 mg Zn/kg live weight per day. Mean plasma Zn concentrations in these animals fell from pre-experiment values of between 0.8 and 1.2 μg Zn/ml to below 0.4 μg Zn/ml after 1 week on these treatments.4. Supplements providing 0.2 mg Zn/kg live weight per day were sufficient to maintain a good rate of growth but insufficient to prevent a fall in plasma Zn.5. Growth arrest occurring within 2 weeks and a rapid fall in plasma Zn occurring within 1 week after Zn supplements were withheld from calves and lambs that had previously received 0.7 mg Zn/kg live weight per day for 6 and 14 weeks respectively indicated that these species have only a limited capacity to store Zn in a form that can be utilized during periods of inadequate Zn intake.6. Tentative estimates are presented of the Zn requirements of calves maintained on this type of basal diet and the influence of ration composition of Zn availability is discussed.7. The possible value and the limitations of plasma Zn determination as an aid to the field diagnosis of Zn deficiency are considered.

Zinc application enhances grain zinc density in genetically-zinc-biofortified wheat grown on a low-zinc calcareous soil

2018 ◽  
pp. 107-110 ◽  
Keyword(s):  
Developing Countries ◽  
Grain Yield ◽  
Calcareous Soil ◽  
Zn Deficiency ◽  
Target Level ◽  
Zn Concentration ◽  
Grain Zinc ◽  
Zn Availability ◽  
Zinc Application ◽  
Grain Zn Concentration

Human zinc (Zn) deficiency is a worldwide problem, especially in developing countries due to the prevalence of cereals in the diet. Among different alleviation strategies, genetic Zn biofortification is considered a sustainable approach. However, it may depend on Zn availability from soils. We grew Zincol-16 (genetically-Zn-biofortified wheat) and Faisalabad-08 (widely grown standard wheat) in pots with (8 mg kg−1) or without Zn application. The cultivars were grown in a low-Zn calcareous soil. The grain yield of both cultivars was significantly (P≤0.05) increased with that without Zn application. As compared to Faisalabad-08, Zincol-16 had 23 and 41% more grain Zn concentration respectively at control and applied rate of Zn. Faisalabad-08 accumulated about 18% more grain Zn concentration with Zn than Zincol-16 without Zn application. A near target level of grain Zn concentration (36 mg kg−1) was achieved in Zincol-16 only with Zn fertilisation. Over all, the findings clearly signify the importance of agronomic Zn biofortification of genetically Zn-biofortified wheat grown on a low-Zn calcareous soil.

Cytologic detection of Toxoplasma gondii in the cerebrospinal fluid of a dog and in vitro isolation of a unique mouse-virulent recombinant strain

2021 ◽  
pp. 104063872199668
Author(s):  
Waléria Borges-Silva ◽  
Mariana M. Rezende-Gondim ◽  
Gideão S. Galvão ◽  
Daniele S. Rocha ◽  
George R. Albuquerque ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
Toxoplasma Gondii ◽  
Recombinant Strain ◽  
Neospora Caninum ◽  
Clinical Signs ◽  
Species Identity ◽  
Cytologic Examination ◽  
Pcr Rflp ◽  
Tissue Homogenates

Parasites resembling Neospora caninum or Toxoplasma gondii were detected by cytologic examination of cerebrospinal fluid (CSF) from a dog with neurologic disease. The dog became severely ill and was euthanized. Canine tissue homogenates were used for direct parasite isolation in cell culture, bioassay in 2 mouse lineages, and PCR. T. gondii was isolated in monkey kidney cells, and species identity was confirmed by PCR. Inoculated parasites were highly virulent for mice, which developed clinical signs and were euthanized immediately. PCR-RFLP for T. gondii using the cultured isolate (TgDgBA22) was conducted with 12 genetic markers, and a unique recombinant strain was identified. Detection of T. gondii by CSF cytology, although described in humans, had not been reported previously in dogs, to our knowledge, and was crucial for the diagnosis of toxoplasmosis in the examined dog.

scholarly journals Calcium-sensitivity of inositol 1,4,5-trisphosphate metabolism in exocrine cells from the avian salt gland

1992 ◽  
Vol 282 (3) ◽  
pp. 703-710 ◽  
Author(s):  
J P Hildebrandt ◽  
T J Shuttleworth
Keyword(s):  
Substrate Concentration ◽  
Inositol Phosphates ◽  
Receptor Activation ◽  
Dependent Manner ◽  
Salt Glands ◽  
Concentration Dependent Manner ◽  
Intact Cells ◽  
Exocrine Cells ◽  
Tissue Homogenates

The generation of inositol phosphates upon muscarinic-receptor activation was studied in [3H]inositol-loaded exocrine cells from the nasal salt glands of the duck Anas platyrhynchos, and the metabolism of different inositol phosphates in vitro was studied in tissue homogenates, with particular reference to the possible interaction of changes in intracellular [Ca2+] ([Ca2+]i) with the metabolic processes. In intact cells, there was a rapid (within 15 s) generation of Ins(1,4,5)P3 and Ins(1,3,4,5)P4, followed by an accumulation of their breakdown products, Ins(1,3,4)P3 and inositol bis- and monophosphates. Ca(2+)-sensitivity of the Ins(1,4,5)P3 3-kinase was demonstrated in tissue homogenates, with the rate of phosphorylation increasing 2-fold at free Ca2+ concentrations greater than 1 microM. However, addition of calmodulin or the presence of the calmodulin inhibitor W-7 (up to 100 microM) had no effect. 3-Kinase activity increased proportionally with the initial Ins(1,4,5)P3 concentration up to 1 microM, but a 10-fold higher substrate concentration produced only a doubling in the phosphorylation rate. Ins(1,3,4,5)P4 was dephosphorylated to Ins(1,3,4)P3, which accumulated in the homogenate assays as well as in intact cells. Depending on its concentration, Ins(1,3,4)P3 was phosphorylated [in part to Ins(1,3,4,6)P4] or dephosphorylated. To investigate the Ca(2+)-sensitivity of the 3-kinase in intact cells, excess quin2 was used to buffer the receptor-mediated transient changes in [Ca2+]i in [3H]inositol-loaded cells. These experiments revealed that increasing [Ca2+]i from less than 100 to approx. 400 nM (i.e. within the physiological range) has no effect on the partitioning of Ins(1,4,5)P3 metabolism (phosphorylation versus dephosphorylation) and on the accumulation of Ins(1,4,5)P3 and Ins(1,3,4,5)P4. This indicates that activation of the 3-kinase by physiologically relevant Ca2+ concentrations may not play a major role in the generation of Ins(1,3,4,5)P4 signals upon receptor activation in these cells. The latter are mainly achieved by the receptor-mediated increase in Ins(1,4,5)P3 in the cell and its phosphorylation by the 3-kinase in a substrate-concentration-dependent manner.

Inhibition in vitro of 4-methyl-coumaryl-7-amide peptide hydrolysis by peptidases in cancer tissue homogenates

1986 ◽  
Vol 14 (5) ◽  
pp. 875-876
Author(s):  
ANIL VASISHTA ◽  
PETER R. BAKER ◽  
PAUL E. PREECE ◽  
ROBERT A. B. WOOD ◽  
ALFRED CUSCHIERI
Keyword(s):  
Cancer Tissue ◽  
Peptide Hydrolysis ◽  
Tissue Homogenates
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