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 ( J V) from 875 ± 86 ( N = 21) to 2130 ± 150 ( N = 21) cm 3·cm −2·10 −7, while the pectoral J V increased from 258 ± 31 ( N = 21) to 545 ± 75 ( N = 21 cm 3·cm −2·10 −7. Captopril inhibited the pelvic patch J V in empty bladder toads decreasing the J V from 978 ± 45 ( N = 27) to 607 ± 38 ( N = 27) cm 3·cm −2·10 −7. In dehydrated toads (15 ± 2%, N = 14), captopril reduced the pelvic patch J V from 1807 ± 213 ( N = 21) to 957 ± 91 ( N = 21) cm 3·cm −2·10 −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.