Vascular perfusion: a novel means of studying oviduct function

An in situ preparation for the combined vascular and luminal perfusion of the rabbit oviduct has been developed. Medium 199, gassed with 5% CO2 in O2 and supplemented with heparin, antibiotics, and 2.5% wt/vol dialyzed bovine serum albumin was infused into the ovarian artery at a rate of 1 ml/min. Krebs Ringer bicarbonate medium was recirculated through the lumen at a rate of 50 microliter/min. The ovary was perfused together with the oviduct, and the preparation is viable for up to 3 h. Equal concentrations of pyruvate, lactate, glucose, and sucrose added to the vascular medium were transported at different rates into the lumen, as was a physiological mixture of amino acids. A proportion of the lactate entering the lumen was synthesized within the oviduct from vascular glucose. When glucose and pyruvate were omitted from the vascular medium, their appearance and that of lactate in the lumen was barely detectable, suggesting that these oviduct fluid components are mainly derived from the blood. The oviduct maintained a steady transmural potential difference of 5.9 mV (lumen negative). With vascular perfusion alone, oviduct fluid entered the oviduct lumen at a rate of 16.8 microliter/h. In oviducts taken from rabbits 3 days postovulation, there was a general decrease in the vascular to lumen flux of all nutrients measured. Preliminary work has shown that the preparation may be used to study ovulation, ovum pickup and transport, and fertilization.