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Biomedical subjects

F Vandesande

Publications and source records attributed to F Vandesande.

At least 127 records · Page 7Linked to original sources

Coexistence of cholecystokinin and oxytocin-neurophysin in some magnocellular hypothalamo-hypophyseal neurons.

The existence of cholecystokinin in the posterior hypophysis and its hypothalamic origin have been unequivocally demonstrated. Immunocytochemical evidence is presented for the coexistence of gastrin-cholecystokinin and oxytocin-neurophysin I immunoreactivities in some magnocellular neurons of the supraoptic and paraventricular nuclei both in rat and bovine hypothalamus.

Animals↗

The origin of somatostatin fibers in the median eminence and neural lobe of Rana temporaria.

A light microscopic immunocytochemical study of the brain of frogs with hypothalamic lesions was performed in order to obtain evidence concerning the origin of somatostatin fibers in the median eminence and neural lobe of the hypophysis. The results indicate that the somatostatin fibers of the neural lobe originate from somatostatin perikarya located in the prechiasmatic part of the hypothalamus and possibly also in the telencephalon. The somatostatin neurons of the pars ventralis tuberis cinerei do not send axons to the neural lobe. The frog median eminence contains axon terminals of somatostatin neurons located in the pars ventralis of the tuber cinereum. Many other somatostatin fibers of the frog median eminence originate from somatostatin neurons located outside the tuber cinereum. Most of these neurons probably lie in the preoptic hypothalamic region.

Animals↗

Immunohistochemical study of embryonic chick heart invaded by malignant cells in three-dimensional culture.

MO4 mouse fibrosarcoma cells, B16 mouse melanoma cells, HeLa human cervical carcinoma cells, and LICR (LOND)-HN-4 human laryngeal carcinoma cells were shown to invade into precultured fragments of 9-day-old chick cardiac muscle in three-dimensional culture. Paraffin sections from such cultures were stained with an antiserum against chick heart following the unlabeled antibody enzyme method. The immunostaining demonstrated (1) differences in the rate and the way by which the four types of malignant cells occupied and replaced the chick cardiac muscle, and (2) the phagocytic activity of the four types of invading cells in three-dimensional culture.

Animals↗

Immunocytochemical localization of somatostatin in the brain of the lizard, Ctenosauria pectinata.

The brain of the lizard, Ctenosauria pectinata, was studied light microscopically using an immunocytochemical staining method that is specific for neurohypophysial hormones and somatostatin. It was shown that the telencephalon and particularly the diencephalon contain somatostatin-producing perikarya, while somatostatinergic fibers occur in the entire brain. Similar to the situation in other vertebrates, somatostatin neurons in Ctenosauria pectinata form a population distinct from the neurohypophysial hormone-producing neurons. The small-sized somatostatin neurons were found in the cortex and the diencephalon: (1) ventral from, and partially overlapping with, the classical neurosecretory paraventricular nucleus; and (2) in the region of the infundibular (tuberal) nucleus. Somatostatin fibers were found among the classical neurosecretory fibers of the supraoptico-paraventricular system (tract, median eminence, neural lobe), near to and within the epiphysis, in the septum, in the vicinity of the tectum opticum and the cerebellum, and in the tegmentum.

Animals↗

Immunocytochemical localization of somatostatin-containing neurons in the brain of Rana temporaria.

The brain of the frog Rana temporaria was studied at the light microscopic level with the use of a double immunocytochemical staining method. The telencephalon, diencephalon and rhombencephalon contain somatostatin perikarya and fibers. In the telencephalon, the location of the somatostatin neurons largely corresponds to that of mammals. In the hypothalamus, the somatostatin perikarya are located in and near the magnocellular preoptic nucleus and also in the pars ventralis of the tuber cinereum. Like the somatostatin neurons of the rat hypothalamus, they form a separate subpopulation, different from the neurons producing neurohypophysial hormones. In Rana, somatostatin neurons are also present in (as well as in the vicinity of) the subfornical organ, in the thalamus, the tectum opticum, the interpeduncular nucleus and the caudal end of the roof of the calamus scriptorius. A precise localization of the perikarya of most somatostatin fibers, including those found in the median eminence and the neural lobe, was not attained.

Amygdala↗

Immunocytochemical localization of the posterior lobe hormones and of their carrier proteins.

Serial sections of vertebrate hypothalami were stained with the immunocytochemical peroxidase-antiperoxidase method. In addition to the single staining method, our double staining method was used, which enabled us to visualize two tissue antigens in single tissue sections. In both staining methods, differentially adsorbed antineurohypophysial hormone sera, anti-somatostatin serum and anti-bovine neurophysin sera were used. The results confirm the one hormone, one neuron hypothesis.

Animals↗

The activated hypothalamic magnocellular neurosecretory system and the one neuron--one neurohypophysial hormone concept.

The activated hypothalamic magnocellular neurosecretory system of the rat was studied in tissue sections, double stained with the unlabeled antibody peroxidase-antiperoxidase complex (PAP) technique. The results indicate that in animals with an activated hypothalamic magnocellular neuroendocrine system, as well as in normal animals, vasopressin and oxytocin are exclusively synthesized in separate vasopressinergic and oxytocinergic neurons.

Animals↗

Immunocytochemical demonstration of separate vasopressin-neurophysin and oxytocin-neurophysin neurons in the human hypothalamus.

With the use of immunocytochemistry, it was shown that both the supraoptic and paraventricular hypothalamic nuclei in humans contain at least two different neurophysins. These two human neurophysins are immunologically related to bovine neurophysin I and neurophysin II, respectively. One human neurophysin is associated with vasopressin, the other wiht oxytocin. Human vasopressin-neurophysin and oxytocin-neurophysin are located separately in two different types of neurons, which correspond respectively to the vasopressinergic and oxytocinergic neurons of both the supraoptic and paraventricular nuclei. The neurophysin of the human vasopressinergic suprachiasmatic neurons appears to be closely related to or identical with neurophysin of the vasopressinergic neurons of the human magnocellular hypothalamic nuclei.

Animals↗

Electron microscopic immunocytochemical demonstration of separate vasotocinergic and mesotocinergic nerve fibres in the median eminence of the frog hypophysis.

With the use of the unlabelled antibody peroxidase-antiperoxidase complex (PAP) technique at the electron microscopic level, it was shown that both the internal and the external regions of the median eminence of the frog contain separate vasotocinergic and mesotocinergic nerve fibres. This observation confirms the results of previous immunocytochemical studies at the light microscopic level. The mean size of the neurohypophysial hormone-containing granules in the external region of the median eminence is significantly smaller than that of the neurohypophysial hormone-containing granules in the internal region of the median eminence. No significant difference could be found between the mean granule size of the vasotocinergic and mesotocinergic fibres of either the internal or the external region of the frog median eminence.

Animals↗

Immunocytochemical localization of vasotocin and mesotocin in the hypothalamus of lacertilian reptiles.

The hypothalamic magnocellular neurosecretory system of lizards was studied with the unlabeled antibody peroxidase-antiperoxidase complex (PAP) technique at the light microscopic level. It was shown that vasotocin and mesotocin are synthesized in separate neurons. The vasotocinergic as well as the mesotocinergic perikarya are of different sizes. Both cell types occur in close juxtaposition, but without a distinct pattern of distribution. The external zone of the lacertilian median eminence contains numerous immunoreactive vasotocinergic fibers and only few immunoreactive mesotocinergic fibers. The general organization of the hypothalamic magnocellular neurosecretory system of lizards, as revealed by immunocytochemistry, is essentially similar to that revealed with unspecific staining methods.

Animals↗

Immunocytochemical localization of somatostatin-containing neurons in the rat hypothalamus.

The rat hypothalamus was studied at the light microscopic level with the use of single and double immunocytochemical staining methods. It was shown that the rat supraoptic and paraventricular hypothalamic nuclei, and their accessory neurosecretory nuclei, do not contain magnocellular somatostatin neurons. The distribution of the hypothalamic parvocellular somatostatin cells is described. The parvocellular component of the rat hypothalamic paraventricular nucleus is, at least partly, composed of somatostatin cells: they form a fairly well circumscribed periventricular cell mass. The rat suprachiasmatic nuclei contain separate somatostatin neurons and vasopressin neurons. Scattered somatostatin cells are present in the entire arcuate nucleus. In addition to the periventricular somatostatin cells located in the preopticanterior hypothalamic area in the arcuate nucleus, the rat hypothalamus also contains numerous scattered somatostatin cells located distant from the third ventricle.

Animals↗

Immunocytochemical study of the neurohypophysial hormone producing system of the lungfish, Protopterus aethiopicus.

Using the unlabeled antibody peroxidase-antiperoxidase complex (PAP) technique at the light microscopic level, it has been shown that, in the dipnoan preoptico-hypophysial neurosecretory system, vasotocin and mesotocin are synthesized in separate neurons. In the preoptic nuclei, the perikarya of these two types of neurosecretory neurons are not located preferentially. The two types of neurosecretory perikarya give rise to separate vasotocinergic and mesotocinergic axons, respectively. The dipnoan median eminence and neural lobe contain separate vasotocinergic and mesotocinergic nerve fibres, the general distribution of which is described. In the pars distalis and the pars intermedia of the hypophysis, neurohypophysial hormone-containing nerve fibres have not been found.

Animals↗

Immunocytochemical investigation of the hypothalamo-neurohypophysial system in birds.

The results of an immunohistochemical investigation of the hypothalamo-neurohypophysial system in several species of birds have shown that: (1) mesotocin and vasotocin are synthesized in separate neurons; (2) in all species investigated the distribution of mesotocinergic and vasotocinergic perikarya follows a common pattern; (3) the external zone of the avian anterior median eminence contains exclusively vasotocinergic nerve fibers, originating in supraoptic and ventral paraventricular regions; (4) the distribution of immunoreactive elements in the neural lobe shows a definite species-dependent pattern.

Animals↗

Immunocytochemical localization of the vasopressinergic and the oxytocinergic neurons in the human hypothalamus.

The human hypothalamic-neurohypophysial hormone-producing nuclei were investigated with the unlabeled antibody peroxidase-antiperoxidase complex (PAP) technique at the light microscopic level. The size, shape and location of the supraoptic, paraventricular, accessory supraoptic and suprachiasmatic nuclei were determined. It was demonstrated in the human hypothalamus, as well as in the hypothalamus of other mammals, that vasopressin and oxytocin are synthesized in separate neurons. In each of the nuclei of the magnocellular neurosecretory system, the distribution, ratios and structural features of the vasopressinergic and oxytocinergic neurons were determined. It was shown that the human suprachiasmatic nuclei contain numerous neurophysin-vasopressin-producing neurons.

Female↗

The origin of the vasopressinergic and oxytocinergic fibres of the external region of the median eminence of the rat hypophysis.

The origin of the vasopressinergic and oxytocinergic nerve fibres of the external region of the rat median eminence was investigated by means of hypothalamic lesions, adrenalectomy and immunocytochemistry. The results obtained in bilaterally adrenalectomized animals with complete, or incomplete, destruction of the suprachiasmatic nuclei showed that, at least, the great majority of the vasopressinergic and oxytocinergic nerve fibres of the external region of the rat median eminence do not originate from the suprachiasmatic nuclei. From the observations obtained in bilaterally adrenalectomized animals with total or subtotal destruction of both paraventricular hypothalamic nuclei, it appears that the paraventricular nuclei must be the origin of (nearly) all the vasopressinergic and oxytocinergic nerve fibres of the external region of the rat median eminence. The results strongly suggest that both types of fibres originate from all parts of the paraventricular nuclei.

Adrenalectomy↗