Search PubMed⌕ Search

Biomedical subjects

F Vandesande

Publications and source records attributed to F Vandesande.

At least 145 records · Page 8Linked to original sources
PubMed1977

Immunocytochemical demonstration of thehypothalamo-hypophysial vasotocinergic system of Lampetra fluviatilis.

With the use of the unlabeled antibody peroxidase-antiperoxidase (PAP) technique at the light microscopic level, it was shown that the preoptico-hypophysial neurosecretory system of the adult migrating Lampetra fluviatilis is a vasotocinergic system. It does not synthesize vasopressin. The results are entirely consistent with earlier chromatographic and pharmacological indications thatit produces little or no oxytocin-like peptide hormone. In the adenohypophysis, immunoreactive neurohypophysial peptidergic fibres are absent.

Animals↗
PubMed1977

Immuno-cytochemical demonstration, in the external region of the amphibian median eminence, of separate vasotocinergic and mesotocinergic nerve fibres.

By means of single and double immuno-enzyme cytochemical staining techniques, it was shown that the external region of the amphibian median eminence contains separate vasotocinergic and mesotocinergic nerve fibres. Moreover, it was demonstrated that the vasotocinergic fibres also contain neurophysin. In animals in which the hypothalamic magnocellular neurosecretory preoptic nuclei had been completely removed, the immuno-reactive vasotocinergic and mesotocinergic fibres of the median eminence had disappeared. From this result, it is concluded that, at least the great majority of the vasotocinergic and mesotocinergic fibres of the external region of the amphibian median eminence are processes of neurosecretory perikarya located in the hypothalamic magnocellular preoptic nuclei. On the other hand, our results do not exclude the possibility that a minority of these neurosecretory fibres originate from small immuno-reactive perikarya which were found in the tuber cinereum. The observation that both kinds of processes accumulate around blood capillaries of the hypophysial portal system strongly suggests that they play a role in the control of the activity of the pars distalis of the hypophysis.

Animals↗
PubMed1976

Immunocytochemical demonstration of separate vasotocinergic and mesotocinergic neurons in the amphibian hypothalamic magnocellular neurosecretory system.

Using the unlabeled antibody peroxidase-antiperoxidase (PAP) technique at the light microscopic level, it was demonstrated that, in the amphibian magnocellular hypothalamo-hypophysial neurosecretory system, vasotocin and mesotocin are synthesized in separate neurons. A tendency to preferential location of the two kinds of neuronal perikarya is described. The neurosecretory perikarya are the origin of separate vasotocinergic and mesotocinergic axons. In the neural lobe, the pattern of distribution of the two types of axons is different. The coarse ventricular "dendrites" of both kinds of neurons are hormone-containing processes. Staining with anti-bovine neurophysin I serum suggested that the vasotocinergic and the mesotocinergic neurons synthesize different neurophysins.

Animals↗
PubMed1976

Immuno-enzyme cytochemical demonstration of mesotocinergic nerve fibres in the pars intermedia of the amphibian hypophysis.

Immuno-enzyme cytochemical investigations showed that the whole amphibian pars intermedia of the hypophysis is innervated by an intercellular network of peptidergic varicose nerve fibres which contain mesotocin or (and) parts of the mesotocin molecule. The pars intermedia does not contain vasotocinergic fibres. The mesotocinergic fibres are branches of axons leaving the pituitary stalk and the neural lobe. In animals of which the hypothalamic magnocellular neurosecretory preoptic nuclei had been completely removed, the immuno-reactive mesotocinergic fibres of the pars intermedia had totally disappeared. From this result, it is concluded that the mesotocinergic fibres of the pars intermedia of the amphibian hypophysis are axons of neurosecretory perikarya located in the hypothalamic magnocellular neurosecretory preoptic nuclei.

Animals↗
PubMed1976

Electron microscopic immunocytochemical demonstration of separate vasotocinergic and mesotocinergic nerve fibres in the neural lobe of the amphibian hypophysis.

Using the unlabeled antibody peroxidase-antiperoxidase (PAP) technique at the electron microscopic level, it was demonstrated that the hormones of the posterior pituitary of Rana temporaria are located in separate vasotocinergic and mesoticinergic nerve fibers. This observation confirms the results of our previous immunocytochemical studies at the light microscopic level.

Animals↗
PubMed1976

Bovine neurophysins I, II and C: new methods for their purification and for the production of specific antibodies.

1. Bovine neurophysins were prepared by a modified method, in which a Biogel P-60 column was used. This yielded two neurophysin fractions, the first containing neurophysin I and small quantities of the other neurophysins,the second containing neurophysin II and C, and only traces of neurophysin I. 2. Antibodies against neurophysin I, II and C were prepared by an original method, 5 mug in 100 mul water of each of the two fractions were applied on a gel slab and separated by iso-electric focusing in a pH gradient 4--6. The separated bands were visualized with 8-aniline-1-naphthalene sulfonic acid, magnesium salt and strips respectively containing neurophysin I, II or C were cut out. The neurophysin-containing strips were homogenized in complete Freund's adjuvant and injected into rabbits. 3. The specificity of the antisera were tested by immunocytochemistry and by radioimmunoassay. By this latter method, it was determined that cross-reactivity was less than 1%. The cross-reaction, observed with the immunohistochemical method could be eliminated by differential absorption. 4. It was found that neurophysin C antisera were undistinguishable from the neurophysin II antisera, while showing little cross-reactivity with the neurophysin I antisera. This suggests that in vivo neurophysin C is not a real neurophysin, or at least, that it is very similar to neurophysin II. 5. Highly purified bovic focusing method. By modifying a LKB Uniphor electrophoresis apparatus, the elute the proteins without switching off the voltage. The resolution of the technique is close to that offered by analytical gel iso-electric focusing.

Animals↗
PubMed1976

Electron microscopic immunocytochemical demonstration of separate neurophysin-vasopressinergic and neurophysin-oxytocinergic nerve fibres in the neural lobe of the rat hypophysis.

By means of the unlabeled antibody peroxidase-antiperoxidase (PAP) technique at the electron microscopic level, it was demonstrated that the hormones of the neural lobe of the rat hypophysis are located in separate neurophysin-vasopressinergic and neurophysin-oxytocinergic nerve fibres. These observations confirm the results of our previous immunocytochemical studies at the light microscopic level.

Animals↗
PubMed1976

Identification, in the external region of the rat median eminence, of separate neurophysin-vasopressin and neurophysin-oxytocin containing nerve fibres.

Immuno-enzyme cytochemical investigations, using single and double staining techniques, showed that the external region of the rat median eminence contains separate neurophysin-vasopressin fibres and neurophysin-oxytocin fibres. These neurophysin-hormone containing nerve fibres are influenced by bilateral adrenalectomy and by colchicine treatment. The external region of the median eminence of the homozygous Brattleboro rat contains neurophysin-oxytocin fibres. It does not contain immuno-reactive neurophysin-vasopressin fibres. Bilateral adrenalectomy also influences the neurophysin-vasopressin containing neurons of the suprachiasmatic nuclei. In the neurons of the parvicellular part of the rat hypothalamic paraventricular nuclei, staining for vasopressin and for oxytocin is completely absent.

Adrenalectomy↗
PubMed1976

Immuno-cytochemical demonstration of the inability of the homozygous Brattleboro rat to synthesize vasopressin and vasopressin-associated neurophysin.

Immuno-enzyme cytochemical investigations have shown that, (1) the hypothalamic supraoptic and paraventricular nuclei of the Brattleboro rat, as in the normal rat, contain separate neurons which produce oxytocin + neurophysin; (2) the hereditary inability of the Brattleboro rat to synthesize vasopressin and its associated neurophysin is due to a biochemical defect of separate "neurophysin-vasopressin" neurons in the supraoptic and the paraventricular nuclei. These observations strongly support the hypotheses that (1) vasopressin and its associated neurophysin are formed via a common precursor, and (2) the initial point of intracellular appearance of the hereditary defect in the Brattleboro rat lies in the synthesis of this precursor, which occurs on ribosomes. Moreover, observations have demonstrated that, in the Brattleboro rat, in addition to the hereditary inability of the hypothalamic magnocellular neurosecretory system to synthesize vasopressin, there also exists a similar hereditary defect in the hypothetical parvicellular suprachiasmatic-median eminence neurosecretory system.

Animals↗
PubMed1975

Identification of the vasopressin producing and of the oxytocin producing neurons in the hypothalamic magnocellular neurosecretroy system of the rat.

Immuno-enzyme histochemical investigations showed that, in the magnocellular hypothalamo-hypophysial neurosecretory system of the rat, vasopressin and oxytocin are synthetized in separate neurons. Both the vasopressin neurons and the oxytocin neurons are present in both the supraoptic and the paraventricular nuclei in about the same number. Preferential location of the two kinds of rat neurosecretory neurons is not as obvious as in the bovine hypothalamus. Their perikarya do not show distinct morphological differences. The two kinds of neurosecretory perikarya are the origin of separate vasopressin-containing and oxytocin-containing axons respectively. In the neural lobe, the distribution of the two different types of axons is described.

Animals↗
PubMed1975

Identification of neurophysin producing cells. III. Immunohistochemical demonstration of neurophysin I-producing neurons in the bovine infundibular nucleus.

Immuno-enzyme histochemical investigations on the bovine hypothalamus showed that the infundibular nucleus contains neurons that produce either neurophysin I or a neurophysin I-like substance. Fine processes of these neurons run in the direction of the median eminence. The possibility that these processes could be the origin of the "neurophysin I-oxytocin" containing nerve fibres of the external region of the median eminence is discussed.

Animals↗
PubMed1975

Identification of separate vasopressin-neurophysin II and oxytocin-neurophysin I containing nerve fibres in the external region of the bovine median eminence.

Immuno-enzyme histochemical investigations showed the presence, in the external region of the bovine median eminence, of accumulations of vasopressin-neurophysin II- and oxytocin-neurophysin I-complexes. These two hormone-neurophysin complexes are located in separate fine varicose nerve fibres. The results strongly plead against an important role of tanycytes in the transport of vasopressin, oxytocin and neurophysins from the cerebrospinal fluid to the hypophysial portal blood-vessels.

Animals↗
PubMed1975

Identification of the vasopressin-neurophysin II and the oxytocin-neurophysin I producing neurons in the bovine hypothalamus.

Immuno-enzyme histochemical investigations on the bovine hypothalamus showed that vasopressin and oxytocin are synthetized in separate neurons. Moreover, it was found that the vasopressin-producing neurons are identical with the neruophysin II-producing neurons, while the oxtocin producing neurons correspond with the neurophysin I-producing neurons. From this result it is concluded that, in the species studied, neurophysin I is the carrier protein of oxytocin and that neurophysin II is the carrier protein of vasopressin. The bovine vasopressin-neurophysin II producing neurons and the oxytocin-neurophysin I producing neurons are both present as well in the suparoptic nuclei as in the paraventricular nuclei. In the supraoptic nuclei, the vasopressin-neurophysin II neurons predominate in number; in the paraventricular nuclei, the oxytocin-neurophysin II neurons predominate. The two kinds of bovine neurosecretory neurons are partly localized in separate areas. Moreover, the vasopressin-neurophysin II neurons and the oxytocin-neurophysin I neurons show distinct morphological differences.

Animals↗