Hyaluronan efflux from XXXX lung with increased hydrostatic pressure and saline loading.

@entity235 @entity1989 @entity13275 @entity4358
Although lymphatic washout of hyaluronan during lung hydration has been postulated to deplete lung interstitial hyaluronan content and thereby contribute to the decreased interstitial exclusion of albumin observed under these conditions, this hypothesis has not been directly tested. In anesthetized, ventilated mongrel @entity235 , a prenodal lung lymphatic was cannulated for measurement of lymph flow and hyaluronan concentration. Following baseline measurements, @entity1989 was increased in four steps of 5 cm @entity4358 in Group 1 or set to one pressure ranging between 6 and 32 cm @entity4358 in Group 2. In Group 3, saline (15% body weight) was infused over 30 min and then @entity1989 increased as in Group 2. Invariably, as lymph flow increased in Groups 1 through 3, lymph hyaluronan concentration and hyaluronan flux increased significantly (p < 0.05). In a separate control group, there were no changes in lymph flow, hyaluronan concentration, or hyaluronan flux. In Group 3, lung hyaluronan content at 5 h (0.76 +/- 0.08 mg/g dry weight) was not significantly less than that during baseline (0.88 +/- 0.05 mg/g dry weight), although total @entity13275 content actually increased by 38% over the same time course. In contrast, in the control group, both lung hyaluronan and @entity13275 content remained stable over the experimental period. From these data, approximately 2 to 3% of lung hyaluronan is predicted to leave the interstitium via lymphatic flux per day under baseline conditions. The daily turnover of interstitial hyaluronan by this route increased to 15 to 18% of total content when @entity1989 was elevated and to 54% following saline infusion. Thus, lung hyaluronan can be rapidly mobilized with increased lymph flow.(ABSTRACT TRUNCATED AT 250 WORDS)
