ABSTRACT
An experimental study was carried out on the Mullerian duct cells, i.e. epithelial cells and stromal cells, treated with trypsin and isolated by Percoll gradient centrifugation. Then they were cultured separately. In order to observe the difference of cell death rate induced by Mullerian inhibiting substance (MIS) secreted from gonad, some cells were co-cultured with fetal testis or ovary in the same embryonic age. Other cells were used for immunocytochemistry at the electron microscopic level with anti-MIS serum as primary antibody and peroxidase labelled goat anti-rabbit IgG antiserum or streptavidin colloidal gold as secondary antibody to show the receptor localizations of MIS on epithelial cells and stromal cells. The results showed that the death rate of Mullerian duct epithelial cells induced by MIS secreted from testis was increased as compared with the control cells (P
ABSTRACT
Using electron immunocytochemical method, the ultrastructural distribution and the synaptic connections of CCK-containing neurons in the paraventricular nucleus (PVN) of the rat were studied. The results showed that the CCK-like immunoreactive products located in farge granular vesicles, cytoplasmic matrix, at the periphery of small clear vesicles, rough endoplasmic reticulum and the membrane of mitochondria. The CCK-positive nerve cell bodies were large or small in size and distributed mainly in the medial part of the PVN, subependymal region and the vicinity of capillaries. Some of them as postsynaptic elements formed axosomatic synapses with CCK-negative axonal terminals. The CCK-positive dendrites and axons situated everywhere in the PVN. Some of them as postsynaptic elements formed axodendritic and axoaxonic synapses with CCK-negative structures. Some CCK-positive axonal endings surrounded the capillaries. Other CCK axonal terminals as presynaptic elements formed axosomatic, axondendritic and axo-axonic synapses with CCK-negative structures, respectively. In addition, we have first found that the CCK-positive dendrites penetrated ependyma and contacted directly with the cerebrospinal fluid in third ventricle, the CCK-positive axons traveled in the cavity of third ventricle near the ependyma. The above mentioned results suggested: (1) the soma, dendrite and axon of the CCK-containing neurons and CCK-negetive neurons in the PVN might form local neuronal circuit; (2) the neuron vessel circuit might be established between CCK-containing neurons and the blood vessels in the PVN; (3) the CSFcontacting neurons in the PVN may participate in forming brain-cerebrospinal fluid neurohumoral circuit and regulate functional activity of distal target area through the CSF pathway.