The influence of diabetes mellitus and hypercorticism on the wound healing of experimental myocardial infarction in rats.
In diabetic and glucocorticoid-treated rats myocardial infarction is produced by coronary artery ligation. After the ligation was performed the animals were given 3H-thymidine or 3H-proline at different times. The following parameters were determined: number of DNA- and tropocollagen-synthesizing connective-tissue cells both at the infarction border and infarction site; mean silver-grain density above the nuclei or cells; number of mitoses. The labelling and mitotic indices as well as the standard deviation (in percent) from the mean values were calculated. The following results were obtained: 1. The retarded formation of collagen fibres in diabetic animals is caused by a reduced number of tropocollagen-synthesizing fibroblasts and by a diminished synthesizing performance of the individual cells. 2. Glucocorticoids have a pronounced inhibitory effect on granulation-tissue formation, The 3H--thymidine indices are strikingly low. The synthesis of collagen precursors in the fibroblasts is reduced. The release of tropocollagen from the connective-tissue cells is slowed down.
D000818:Animals; D003094:Collagen / Q000096:biosynthesis; D003238:Connective Tissue / Q000473:pathology; D004247:DNA / Q000096:biosynthesis; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism / Q000473:pathology*; D008297:Male; D008938:Mitosis; D009203:Myocardial Infarction / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology*; D011239:Prednisolone / Q000627:therapeutic use*; D051381:Rats; D014332:Tropocollagen / Q000096:biosynthesis
D014332:Tropocollagen; D003094:Collagen; D004247:DNA; D011239:Prednisolone