Human atrial natriuretic peptide infusion and ovarian venous progesterone secretion in Yucatan micropigs

Chronic indwelling catheters were implanted in the ovarian and external jugular veins of Yucatan micropigs during the luteal phase. Infusion of hypertonic saline (0.4 mol NaCl l-1) increased the concentration of porcine immunoreactive atrial natriuretic peptide in ovarian venous blood plasma by 0.61-1.81 fmol ml-1 more than that of the saline control group. Conversely, endogenously released porcine immunoreactive atrial natriuretic peptide was associated with low ovarian venous progesterone concentrations. Infusion of human atrial natriuretic peptide induced a dose-dependent increase in the progesterone concentration in ovarian venous blood. The results reported here suggest a duality in the ovarian response to atrial natriuretic peptide: a decrease in progesterone secretion in response to low concentrations and stimulated progesterone secretion in response to high concentrations of this peptide.