Rsc. Horne et al., EFFECT OF ARGININE-VASOPRESSIN AND PARATHYROID HORMONE-RELATED PROTEIN ON RENAL-FUNCTION IN THE OVINE FETUS, Clinical and experimental pharmacology and physiology, 20(9), 1993, pp. 569-577
1. The effects of intravenous infusions of arginine vasopressin (AVP),
parathyroid hormone-related protein (PTHrP) and AVP + PTHrP on renal
function in intact ovine foetuses at 100-125 days of gestation were ex
amined. 2. A low dose of AVP (5.5 +/- 0.9 pmol/h) increased plasma AVP
concentrations from 0.6 pmol/ L to 2.1 +/- 0.4 pmol/ L (mean +/- s.e.
m; n = 8). This dose caused a significant reduction in free water clea
rance (C(H2O); P<0.001), without any significant change in fetal arter
ial blood pressure, glomerular filtration rate (GFR), or the urinary e
xcretion rates of sodium, calcium or 3', 5'-cyclic adenosine monophosp
hate (cAMP). 3. Infusions of PTHrP (1 nmol/h), with or without 1 nmol
bolus dose, significantly increased (P<0.05) urine osmolality (U(OSM),
but did not synergize with AVP in reducing C(H2O). 4. It is concluded
that AVP and PTHrP do not act synergistically on the kidney of the in
tact ovine foetus.