Tim R. Kramer

Lymphoid cell functions during copper deficiency

Abstract Male weanling Lewis rats were fed diets either adequate (5.6 μg/g) or low (0.6 μg/g) in copper, either and libitum or in restricted amounts for 14–70 days. Measurements were made of food intake; growth rate; hematocrits; Cu and Fe concentrations of plasma or serum; ceruloplasmin activity of plasma or serum; plasma cholesterol and whole blood lactate concentrations; cytochrome c oxidase activity of spleen lymphoid cells (SLC); and proliferation of SLC, cervical lymph node cells (CLNC) and plastic nonadherent-SLC (NASLC) following stimulation with concanavalin-A (Con-A). Cu-deficient (CD) rats exhibited upon completion of dietary regimen days: 14–18, reduced hematocrits, plasma Cu and Fe, plasma ceruloplasmin activity and cytochrome c oxidase activity of SLC; 28–32, elevated plasma cholesterol and blood lactate, decreased proliferation of Con-A stimulated SLC, but increased proliferation of Con-A stimulated CLNC; and 42–46, reduced food intake and growth. Suppressed proliferation of Con-A stimulated SLC from CD rats was not alleviated following removal of plastic-adherent lymphoid cells from the SLC suspension. Equivalent proliferation was exhibited by Con-A stimulated SLC from CD rats and NASLC from CD and CA rats. In conclusion, reduced T-lymphocyte proliferation in copper-deficiency: is influenced by the tissue source of lymphoid cells; is not due to impaired ability of T-lymphocytes to proliferate; and may be due to imparied enhancer function for T-lymphocyte proliferation by macrophages.

Fatty acid pattern of tissue phospholipids in copper and iron deficiencies

Because copper and iron have been reported to be essential cofactors in Δ9 desaturation of fatty acids, the effects of different dietary intakes of copper and iron on tissue fatty acids were studied. Male Long-Evans rats (ten per group) were fed diets containing adequate, deficient or excess copper or iron. On day 42 of the dietary regimen, the animals were killed and tissues and blood were removed for analysis of metals and fatty acids of phospholipids. Compared with the copper-adequate rats, the copper-deficient rats showed increased 18∶0 in liver and decreased 16∶1ω7 in liver, heart and serum. There were no differences for 16∶0 or 18∶1ω9. Intake of excess copper did not cause an increase in products of Δ9 desaturation. Comparisons between iron-deficient and iron-adequate rats showed that iron deficiency increased 18∶2ω6 in liver and serum and decreased 20∶4ω6 in serum only. Relative percentages of 16∶0, 18∶0, 16∶1ω7 and 18∶1ω9 in liver and serum phospholipids were similar for both groups. Intake of excess iron caused a decrease in 18∶2ω6; and 16∶0 and 18∶1ω9 were higher in the liver of the iron-excess group than the iron-deficient group. This study did not support the requirement for copper or iron in the Δ9 desaturation of fatty acids as expressed in phospholipids of liver, heart and serum.

Polyunsaturated fatty acid patterns in lymphoid and nonlymphoid tissues of zinc deficient and pair-fed rats

Abstract The influences of zinc-deficiency and reduced food intake on levels of polyunsaturated fatty acids (PUFA) of phospholipids (PL) of lymphoid and nonlymphoid tissues were studied. Weanling male Long-Evans rats were fed ad libitum either a zinc-deficient (ZD) or a zinc-adequate (ZA) diet for 21 days. A pair-fed (PF) group was given the ZA diet in an amount equal to that consumed on the previous day by the ZD group. Linoleic acid (18:2ω6), 18:3ω6 and 20:3ω6 were either equivalent or significantly higher, but arachidonic acid (20:4ω6) and 22:5ω6 were either equivalent or significantly lower in tissues of ZD and PF rats compared to ZA rats. Total ω6 acids and metabolites were either equivalent or significantly lower in tissues of ZD and PF rats compared to ZA rats. In contrast, total ω3 acids and metabolites, and total ω9 acids and emtabolites were either equivalent or significantly higher in ZD and PF rats compared to ZA rats. Changes in PUFA patterns of lymphoid and nonlymphoid tissues of ZD rats were influenced by reduced food intake.

Influences of dietary polyunsaturated or saturated fats and of concanavalin-a upon proliferation of spleen lymphoid cells from rats

Abstract The effects of dietary polyunsaturated and saturated fats upon several metabolic phenomena were studied in rats. These included phospholipid (PL) levels in unstimulated spleen lymphoid cells (SLC) and serum; in vitro proliferation of unstimulated SLC from the two groups of rats; the influence of mitogenic concanavalin-A (Con-A) on in vitro proliferation of SLC from the two groups of rats; and the influence of serum from the two groups of rats on SLC proliferation. Weanling male Long-Evans rats were fed ad libitum either a polyunsaturated fatty acid (PUFA)-adequate (safflower oil, SO) or PUFA-deficient (coconut oil, CNO) diet for 21 days. Growth was significantly less in the CNO group than in the SO group. Food intake was not different for the dietary groups. Unstimulated SLC and serum of CNO rats showed changes in fatty acid composition of PL typical of tissue PL in essential fatty acid-deficient (EFA-D) rats. Unstimulated SLC from the two groups cultured in medium containing serum from the same groups showed equivalent rates of in vitro proliferation. In vitro proliferations of SLC were influenced: by the dietary source of SLC but not by the dietary source of serum, used in the culture medium, when the cells were stimulated by suboptimal doses of Con-A; by the dietary source of serum but not by the dietary source of SLC when the cells were stimulated by the optimal dose of Con-A; and by an interaction between source of SLC and serum, when the cells were stimulated by a supra-optimal dose of Con-A. The present study indicates that in vitro proliferation of SLC from PUFA-adequate and PUFA-deficient rats is influenced by both the dietary source of serum used in the culture medium and the concentration of Con-A used for stimulation of the SLC.

Influence of zinc on bacillus calmette-guerin cell wall skeleton induced suppression of concanavalin-a stimulated DNA-synthesis of rat splenic T-lymphocytes

Abstract Weanling male Lewis rats consuming a Low-Zn (ZnD) diet (2 ug/g) for 21 days and injected seven days prior to completion of dietary regimen with either incomplete Freunds adjuvant (IFA) or IFA containing Bacillus Calmette-Guerin cell wall skeleton (BCGcws) showed reduced growth and serum Zn. IFA treated rats fed a restricted amount (PF) of adequate-Zn (ZnA) diet (20 ug/g) showed reduced growth. BCGcws injection caused reduced food intake, growth and serum Zn in rats fed the ZnA diet ad libitum, and reduced serum Zn in PF rats. BCGcws injection caused reduced concanavalin-A (Con-A) induced DNA-synthesis of splenic T-lymphocytes from rats of each dietary group. Suppressed mitogenic reactivity of splenic T-lymphocytes to Con-A and enhanced phagocytic activity of spleen lymphoid cells from BCGcws injected rats were normalized after removal of lymphoid cells which adhere to plastic (macrophage like). The present study shows that low-zinc fed rats maintain mitogenic reactivity of T-lymphocytes to Con-A, and suppressor activity of splenic macrophages, stimulated in vivo with BCGcws, on Con-A stimulated blastogenesis of splenic T-lymphocytes.

Erythrocytes and latex particles enhance blastogenesis of concanavalin-A stimulated spleen lymphoid cells from copper deficient rats.

Abstract Male weanling Lewis rats were fed two concentrations of copper (0.6 or 5.6 ug Cu/g diet) for 42 days. Rats consuming the low copper diet had lower hemoglobin, hematocrit, serum ceruloplasmin activity, and copper and iron concentrations than those fed the adequate copper diet. Copper-deficient (CuD) rats had elevated liver iron. Concanavalin-A (Con-A)-induced incorporation of 3 H-thymidine ( 3 H-TdR) was suppressed in erythrocyte-free suspensions of splenic lymphoid cells from CuD rats, but not in spleen cell suspensions containing resident erythrocytes. Addition of either erythrocytes or latex particles to preparations of splenic lymphoid cells that had been treated with ammonium chloride (LSLC) enhanced the mitogenic reactivity of splenic T-lymphocytes from CuD rats relative to that of the controls. LSLC from CuD rats required four times as many latex particles per cell for maximal T-lymphocyte reactivity to Con-A than did cells from copper-adequate (CuA) rats. These results suggest that copper deficiency is associated with enhanced activity or number of suppressor macrophages in the spleen. Such an alteration may contribute to the immunocompromised state found in copper-deficient rodents.