Empty bladder and dehydrated pelvic patch water uptake in Bufo marinus: inhibition by captopril.

Dehydration (10.3 +/- 2.2%, N = 7) caused a significant increase in pelvic patch water uptake (Jv) from 875 +/- 86 (N = 21) to 2130 +/- 150 (N = 21) cm3.cm-2 x 10(-7), while the pectoral Jv increased from 258 +/- 31 (N = 21) to 545 +/- 75 (N = 21 cm3.cm-2 x 10(-7). Captopril inhibited the pelvic patch Jv in empty bladder toads decreasing the Jv from 978 +/- 45 (N = 27) to 607 +/- 38 (N = 27) cm3.cm-2 x 10(-7). In dehydrated toads (15 +/- 2%, N = 14), captopril reduced the pelvic patch Jv from 1807 +/- 213 (N = 21) to 957 +/- 91 (N = 21) cm3.cm-2 x 10(-7). Captopril injection decreased the blood pressure in dehydrated toads from 25.6 +/- 1.9 (N = 21) to 16.9 +/- 1.5 (N = 21) mmHg with no change in heart rate.