Hypophyseal Portal Blood Collection for Analysis of GnRH Neurosecretion in Shiba Goats

抄録

Sequential sampling of hypophyseal portal blood was performed in the Shiba goat. The technique for portal blood collection originally developed for sheep was adapted with some modification. Portal blood was withdrawn by lesioning a part of the pituitary portal vessels via a collection apparatus placed beforehand at the rostral surface of the anterior pituitary gland. In four ovariectomized goats, portal blood was collected successively at 5 min intervals for several hours to examine the neurosecretory dynamics of hypothalamic GnRH. A pulsatile pattern of GnRH discharge into the pituitary portal circulation was clearly observed. Mean ± SD inter-pulse intervals in each of the 4 animals were 29.0 ± 2.0 min, 38.8 ± 2.2 min, 29.3 ± 1.7 min and 23.9 ± 2.1 min. Each GnRH pulse was associated with an LH pulse, and temporal correlation between the GnRH and LH pulses was consistent despite differing pulse frequencies among individual animals. Thus the technique for continuous pituitary portal blood collection from conscious goat has become available.