RENAL FUNCTION AND ITS RELATION TO ECOLOGY OF VAMPIRE BAT DESMODUS ROTUNDUS

1. 1. Blood consumption in 7-hr experimental periods (blood available first 2 hr) averaged 37·4 per cent/body wt. 2. 2. Urine averaged 40·5 per cent/blood consumed, with 62 per cent voided in the first hour. 3. 3. At peak flow (4·0 ml/kg per min) osmotic concentration was 475 mOsm; 6 1 2hr later the mean high was 4656 mOsm. 4. 4. Ratio urea/mOsm urine reached 0·73, or 68 per cent of total activity. 5. 5. Na and Cl diminished with concentration (90 per cent of activity in dilute urine, 9·5 per cent in concentrated urine), but Na/Cl ratio increased (240 mM Na/60 mM Cl at mean concentration of 4656 mOsm). 6. 6. Potassium (max. 42 mM/l) was uncorrelated with Na, Cl or osmotic concentration. 7. 7. Insensible losses (during 2 hr after feeding at ambient temperature 23·5-25°C) were 13·7 per cent (r.h. 40 per cent) and 8·5 per cent (r.h. 77 per cent) respectively. © 1969.