| 1. |
- Gerdin, Bengt, 1947-, et al.
(författare)
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Selective tissue accumulation of manganese and its effect on regional blood flow and haemodynamics after intravenous infusion of its chloride salt in the rat.
- 1985
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Ingår i: International journal on tissue reactions. - 0250-0868. ; 7:5, s. 373-80
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Tidskriftsartikel (refereegranskat)abstract
- Manganese chloride (MnCl2), with or without the addition of trace amounts of 54Mn2+, was administered as a 7-min i.v. infusion in rats. Tissue accumulation of 54Mn2+ was determined 0-15 min after the infusion, and cardiac output, regional blood flows and vascular resistances were measured 5 and 60 min after the infusion by the microsphere technique. The plasma half-life of 54Mn2+ was found to be 4.7 min. Mn2+ accumulated in several organs, the highest relative concentrations being seen in the liver, duodenum, jejunum, kidney and heart, and intermediate concentrations in the ileum, colon, stomach and spleen. There was no uptake in the lung, skeletal muscle or brain. During the infusion of 180 mumol/kg b.w. of Mn2+, the arterial blood pressure fell from a mean of 123 +/- 5 mm Hg to a minimum of 85 +/- 7 mm Hg, and thereafter returned to normal. Five minutes after termination of the infusion, there was a decrease in cardiac output and minute work but not in total peripheral resistance, a finding interpreted as a negative inotropic effect of Mn2+. At this time blood flow was decreased in the stomach, ileum, colon, spleen and skin, and increased in duodenum, jejunum and liver. The blood flows were normalized 60 min after termination of the infusion in all organs except the liver and heart. The effects are probably due to the calcium-antagonistic properties of Mn2+ and the tissue accumulation is most probably a result of intracellular accumulation through calcium channels. The relation between tissue accumulation and tissue selectivity of blood-flow alterations is unexplained.
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| 2. |
- Lundberg, C, et al.
(författare)
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The inflammatory reaction in healing wounds : the role of polymorphonuclear leucocytes.
- 1984
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Ingår i: International journal on tissue reactions. - 0250-0868. ; 6:6, s. 477-83
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Tidskriftsartikel (refereegranskat)abstract
- The inflammatory process in granulation tissue in full-thickness skin wounds was studied and the role of polymorphonuclear leucocytes (PMNLs) in this process evaluated in an experimental model in the rat. The number of PMNLs in the wound, assessed by determination of the PMNL-specific enzyme myeloperoxidase (MPO) activity in wound exudate, increased from 0.45 U/ml on day 1 after wounding to 0.8 U/ml on day 2, and then remained constant throughout the five days of observation. The concentration of prostaglandin E2 (PGE2) in wound exudate increased progressively from 70 ng/ml on day 1 to 290 ng/ml on day 5. The lack of correlation between these two variables indicated that PMNLs were not the major source of PGE2. Blood flow and albumin extravasation in the granulation tissue were measured, and the relation between these two variables and PMNL accumulation was studied. Rats were rendered neutropenic with an antineutrophil serum, resulting in an 83% decrease in circulating PMNLs and a 61% decrease in granulation tissue MPO activity on day 5, as compared with rats treated with normal rabbit serum. These reductions did not, however, affect either blood flow or albumin extravasation, and no correlation was observed; but when inter-individual variations in the absolute levels of the variables measured were eliminated by calculating in each rat a left-to-right wound ratio, PMNL accumulation correlated well to both blood flow (R = 0.81) and albumin extravasation (R = 0.65). It is suggested that blood flow and albumin extravasation in the granulation tissue are influenced by local PMNL accumulation and, further, that the inflammatory response varies considerably between one animal and another.
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| 3. |
- McCann, E, et al.
(författare)
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Selective actions of calcium antagonistic drugs on the haemodynamics and regional organ blood flow in rats.
- 1986
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Ingår i: International journal on tissue reactions. - 0250-0868. ; 8:3, s. 205-12
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Tidskriftsartikel (refereegranskat)abstract
- Six substances, all of which influence calcium utilization by smooth muscle, namely nimodipine (50 micrograms/kg), flunarizine (1 mg/kg), verapamil (0.2 mg/kg), lidoflazine (1 mg/kg), magnesium (600 mumol Mg++/kg), and manganese (180 mumol Mn++/kg), were given intravenously to rats and their effects on regional blood flows and on cardiac output were determined by the radioactive microsphere technique. All compounds caused a temporary fall in mean arterial blood pressure. Cardiac output was decreased by manganese, and minute work by nimodipine, manganese and lidoflazine. Nimodipine increased blood flow in the liver, skeletal muscle and heart and decreased that in the stomach, ileum, colon, kidney, spleen and skin; manganese increased flow in the duodenum, jejunum, liver and myocardium and decreased that in the stomach, ileum, colon, spleen and skin; flunarizine increased flow in the liver, heart and brain; and magnesium increased flow in the liver, spleen and brain. Lidoflazine and verapamil, although leading to haemodynamic alterations, had no selective effect on organ blood flow. Selective actions by calcium effector drugs can provide information on mechanisms of calcium flux in various types of vascular smooth muscle, and show that it is possible to tailor combinations of anti-calcium agents with optimal effects on a given organ.
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