title: Hyaluronidase reversal of increased coronary vascular resistance in ischemic rat hearts.
abstract: Testicular hyaluronidase prevents increased coronary vascular resistance (CVR) during prolonged myocardial ischemia. The mechanism is unknown, but edema and contracture both have been suggested to increase CVR. Additionally, the extent of contracture has been inversely related to ATP levels. Therefore, isolated perfused ischemic rat hearts were treated with hyaluronidase, following a 25% increase in CVR, to determine whether 1) increased CVR was reversed, 2) edema or contracture was reduced, and 3) tissue ATP levels were increased. Three hours of low-flow ischemia decreased coronary flow (CF) from 17.4 +/- 0.13 to 12.6 +/- 0.2 ml X min-1 X g dry tissue-1. During the subsequent 2 h of ischemia, CF of vehicle-treated hearts continued to decline to 8.0 +/- 0.76 ml X min-1 X g dry tissue-1, whereas CF of hyaluronidase-treated hearts increased to 15.6 +/- 1.17 ml X min-1 X g dry tissue-1. These changes in CF persisted during postischemic perfusion. Furthermore, restoration of coronary vascular resistance by hyaluronidase was associated with a 19% reduction in tissue water compared with control ischemic hearts but not with a reduction in cardiac contracture or an increase in tissue ATP. These results suggest that treatment of ischemic hearts with hyaluronidase reverses increased CVR through a reduction in tissue edema.
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000332:Aerobiosis; D000818:Animals; D001794:Blood Pressure; D003327:Coronary Disease / Q000503:physiopathology*; D003331:Coronary Vessels / Q000187:drug effects / Q000503:physiopathology*; D004195:Disease Models, Animal; D006821:Hyaluronoglucosaminidase / Q000494:pharmacology*; D007700:Kinetics; D008297:Male; D009206:Myocardium / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D014655:Vascular Resistance / Q000187:drug effects*
chemical_list: D000255:Adenosine Triphosphate; D006821:Hyaluronoglucosaminidase