The guinea pig hypothalamo-neurohypophyseal complex in organ culture for oxytocin studies.

The guinea pig hypothalamo-neurohypophyseal complex (HNC) was assessed as a possible in vitro model for oxytocin (OT) studies. The hypothalamus was incised in such a way as to contain intact supraoptic and paraventricular nuclei. The HNC was maintained for a week on a steel grid in Eagle's Minimum Essential culture medium (containing 10% fetal bovine serum and kanamycin 60 mg/1, pH 7.0) and incubated at 37°C under 95% air and 5% CO2. OT released from the HNC into the culture medium in a 20 minute period was measured every day. OT concentrations were fairly constant from Day 1 to Day 7 in culture. The hypothalamus and the pituitary were also incubated in the same conditions as the HNC in culture for comparison. Our studies indicate that OT was released from the HNC in constant quantities. Histological observations under light microscopy showed that the neurosecretory cells remained viable during the culture period. We believe organ culture of the HNC could be a useful model for further OT studies.