Biomaterial Database

Immunocytochemical studies of vasotocin, mesotocin, and neurophysins in the Xenopus hypothalamo-neurohypophysial system. 1987

K M Conway, and H Gainer

Laboratory of Neurochemistry and Neuroimmunology, National Institute of Child Health and Human Development, Bethesda, Maryland 20892.

Mesotocinergic and vasotocinergic neurons, which constitute the principal neurons in the hypothalamo-neurohypophysial system in Xenopus, were studied by immunocytochemical techniques. Antibodies that could unequivocally distinguish mesotocin, vasotocin, and their respective neurophysins were used in these studies. A monoclonal antibody directed at rat oxytocin-associated neurophysin (PS-36) detected an antigen that was colocalized with vasotocin, whereas a monoclonal antibody to rat vasopressin-associated neurophysin (PS-45) crossreacted with an antigen in mesotocinergic cells. As vasotocin is regarded as an evolutionary precursor of vasopressin, and as mesotocin is usually associated with oxytocin, we were surprised to see this apparent eptitope switch in the associated neurophysins. One interpretation of this epitope switch is that the final exons encoding for the carboxy-terminals of the mammalian neurophysins, which contain the PS-45 and PS-36 antibody epitopes, are in reversed positions in Xenopus. Approximately 4,000 mesotocinergic and vasotocinergic neurons and their fibers were topographically mapped in the Xenopus hypothalamus. The two types of neurons were intermingled and scattered throughout a large contiguous region including but not limited to the preoptic recess. Small, medium size, and large cells contained these antigens. Immunoreactive fibers were seen in the preoptic area, the neurohypophysial tract, the median eminence, and the neural lobe of the pituitary. The neurophysin-specific monoclonal antibodies have several advantages as phenotypic markers in development; i.e., high titer, low background, and affinity for the prohormone forms as well as for the fully processed neurophysin polypeptides. Their antigens are related gene products whose expression is central to the identity of the two cell types and whose expression is differentially controlled in development. This characterization of their adult distribution provides a basis for future studies of the development of peptidergic phenotype in the central nervous system of Xenopus.

UI	MeSH Term	Description	Entries
D007030	Hypothalamo-Hypophyseal System	A collection of NEURONS, tracts of NERVE FIBERS, endocrine tissue, and blood vessels in the HYPOTHALAMUS and the PITUITARY GLAND. This hypothalamo-hypophyseal portal circulation provides the mechanism for hypothalamic neuroendocrine (HYPOTHALAMIC HORMONES) regulation of pituitary function and the release of various PITUITARY HORMONES into the systemic circulation to maintain HOMEOSTASIS.	Hypothalamic Hypophyseal System,Hypothalamo-Pituitary-Adrenal Axis,Hypophyseal Portal System,Hypothalamic-Pituitary Unit,Hypothalamic Hypophyseal Systems,Hypothalamic Pituitary Unit,Hypothalamo Hypophyseal System,Hypothalamo Pituitary Adrenal Axis,Portal System, Hypophyseal
D007150	Immunohistochemistry	Histochemical localization of immunoreactive substances using labeled antibodies as reagents.	Immunocytochemistry,Immunogold Techniques,Immunogold-Silver Techniques,Immunohistocytochemistry,Immunolabeling Techniques,Immunogold Technics,Immunogold-Silver Technics,Immunolabeling Technics,Immunogold Silver Technics,Immunogold Silver Techniques,Immunogold Technic,Immunogold Technique,Immunogold-Silver Technic,Immunogold-Silver Technique,Immunolabeling Technic,Immunolabeling Technique,Technic, Immunogold,Technic, Immunogold-Silver,Technic, Immunolabeling,Technics, Immunogold,Technics, Immunogold-Silver,Technics, Immunolabeling,Technique, Immunogold,Technique, Immunogold-Silver,Technique, Immunolabeling,Techniques, Immunogold,Techniques, Immunogold-Silver,Techniques, Immunolabeling
D009474	Neurons	The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.	Nerve Cells,Cell, Nerve,Cells, Nerve,Nerve Cell,Neuron
D009481	Neurophysins	Carrier proteins for OXYTOCIN and VASOPRESSIN. They are polypeptides of about 10-kDa, synthesized in the HYPOTHALAMUS. Neurophysin I is associated with oxytocin and neurophysin II is associated with vasopressin in their respective precursors and during transportation down the axons to the neurohypophysis (PITUITARY GLAND, POSTERIOR).	Neurophysin,Neurophysin I,Neurophysin II,Neurophysin III,Oxytocin-Associated Neurophysin,Vasopressin-Associated Neurophysin,Neurophysin, Oxytocin-Associated,Neurophysin, Vasopressin-Associated,Oxytocin Associated Neurophysin,Vasopressin Associated Neurophysin
D010121	Oxytocin	A nonapeptide hormone released from the neurohypophysis (PITUITARY GLAND, POSTERIOR). It differs from VASOPRESSIN by two amino acids at residues 3 and 8. Oxytocin acts on SMOOTH MUSCLE CELLS, such as causing UTERINE CONTRACTIONS and MILK EJECTION.	Ocytocin,Pitocin,Syntocinon
D010904	Pituitary Gland, Posterior	Neural tissue of the pituitary gland, also known as the neurohypophysis. It consists of the distal AXONS of neurons that produce VASOPRESSIN and OXYTOCIN in the SUPRAOPTIC NUCLEUS and the PARAVENTRICULAR NUCLEUS. These axons travel down through the MEDIAN EMINENCE, the hypothalamic infundibulum of the PITUITARY STALK, to the posterior lobe of the pituitary gland.	Neurohypophysis,Infundibular Process,Lobus Nervosus,Neural Lobe,Pars Nervosa of Pituitary,Posterior Lobe of Pituitary,Gland, Posterior Pituitary,Infundibular Processes,Lobe, Neural,Lobes, Neural,Nervosus, Lobus,Neural Lobes,Pituitary Pars Nervosa,Pituitary Posterior Lobe,Posterior Pituitary Gland,Posterior Pituitary Glands,Process, Infundibular,Processes, Infundibular
D004027	Diencephalon	The paired caudal parts of the PROSENCEPHALON from which the THALAMUS; HYPOTHALAMUS; EPITHALAMUS; and SUBTHALAMUS are derived.	Interbrain,Interbrains
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D014018	Tissue Distribution	Accumulation of a drug or chemical substance in various organs (including those not relevant to its pharmacologic or therapeutic action). This distribution depends on the blood flow or perfusion rate of the organ, the ability of the drug to penetrate organ membranes, tissue specificity, protein binding. The distribution is usually expressed as tissue to plasma ratios.	Distribution, Tissue,Distributions, Tissue,Tissue Distributions
D014668	Vasotocin	A nonapeptide that contains the ring of OXYTOCIN and the side chain of ARG-VASOPRESSIN with the latter determining the specific recognition of hormone receptors. Vasotocin is the non-mammalian vasopressin-like hormone or antidiuretic hormone regulating water and salt metabolism.	3-Isoleucyl Vasopressin,Arginine Oxytocin,Arginine Vasotocin,Argiprestocin,Vasopressin, Isoleucyl,Vasopressin, Non-Mammalian,(8-Arginine)Oxytocin,Argiprestocine,3 Isoleucyl Vasopressin,Isoleucyl Vasopressin,Non-Mammalian Vasopressin,Oxytocin, Arginine,Vasopressin, 3-Isoleucyl,Vasopressin, Non Mammalian,Vasotocin, Arginine