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Biomedical subjects

M Chvapil

Publications and source records attributed to M Chvapil.

At least 163 records · Page 9Linked to original sources
PubMed1976

Regulation of some functions of granulocytes by zinc of the prostatic fluid and prostate tissue.

Oxygen consumption, phagocytosis, and activity of hexosomonophosphate shunt (HMS) of dog and human polystyrene latex-activated polymorphonuclear leukocytes were inhibited by normal and infected human prostatic fluid (PF) and prostate extract; resting cells were not affected. Granulocytes incubated in 7 per cent PF increased five times their zinc content. Inorganic zinc added to synthetic medium which contained activated granulocytes also inhibited O2 consumption and phagocytosis of yeast particles in a concentration-dependent manner; resting cells were not affected. Incubation of PF with CaNa2 ethylenediamine tetraacetic acid (EDTA) abolished the inhibitory effect of PF; extensive dialysis of PF against this chelating agent reduced the inhibition by half. After the PF was dialyzed against saline, the low molecular weight dialysate retained inhibitory effects. Extracts from dog liver, spleen, and human saliva were not inhibitory. Polyamines, which next to zinc are also present in PF in high concentrations, had no effect on granulocytes, O2 consumption, and HMS activity. Human as well as dog PF were inhibitory to human or dog granulocytes, respectively. Besides granulocytes, rat peritoneal macrophages were inhibited by PF as well. It is concluded that PF and extract from prostate inhibit various functions of phagocytes mainly because of high concentration of zinc. The existence of other, large molecular weight, heat-resistant substances in PF which contribute to zinc effect cannot be ruled out.

Animals↗
PubMed1975

Oxygen and lung fibrosis.

Young adult rats were continuously exposed to environments containing 9% to 10%, 20% and 80% oxygen for 41 and 84 days. Animals exposed to both extreme oxygen concentrations demonstrated a noticeably slowed body growth, and the weight of the lungs was proportionally lower. Total amount and density of hydroxyproline in the lungs of both groups was markedly higher than in rats exposed to an ambient atmosphere. At both extreme oxygen concentrations, the content of lactate in the lung and total lactate dehydrogenase (LDH) activity were markedly higher, as was the activity of prolyl hydroxylase. The finding of enhanced peroxidizability of lipids in the lungs (examined by determination of malonaldehyde and change in the profile of fatty acids) indicates that both extreme oxygen concentrations represent an injury to lung constituents. We propose that under chronic exposure to low (9% to 10%) or high (80%) oxygen, the lung tissue was damaged (enhanced peroxidizability of lipids). It also developed inflammatory changes (increased lactate and LDH activity) that resulted in the enhancement of fibroplasia (increased activity of prolyl hydroxylase and collagen content). It is also possible that the content of tissue lactate in vivo situations may control the activity of prolyl hydroxylase.

Animals↗