Cytophysiology of the Teleost Pituitary

Sage, Martin; Bern, Howard A.

doi:10.1016/s0074-7696(08)60062-5

Cited by 82 publications

(23 citation statements)

References 203 publications

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“…The potential for interactions between the two systems is considerable. Interactions have been suggested (Pickford and Atz, 1957;Berg et al, 1959;Ball, 1960;Matty, 1960Matty, , 1985Dodd and Matty, 1964;Gorbman, 1969;Singh, 1970;Sage and Bern, 1971;Dodd, 1975Dodd, , 1983Donaldson and Hunter, 1983), and reviewed more extensively by Eales (1979), Nagahama (1983), Leatherland (1987, 1994), and Dickhoff et al (1989. Sage (1973) has pointed out the structural similarities between thyroid-stimulating hormone (TSH)" and gonadotrophins and suggested some role of the thyroid in regulation of fish reproduction.…”

mentioning

confidence: 99%

Interrelationships between thyroidal and reproductive endocrine systems in fish

Cyr

Eales

1996

Rev Fish Biol Fisheries

187

127

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mentioning

confidence: 99%

Interrelationships between thyroidal and reproductive endocrine systems in fish

Cyr

Eales

1996

Rev Fish Biol Fisheries

187

127

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“…Previous studies have indicated that these fibers do not enter the RPD (27). In goldfish, glutamate-immunopositive fibers have been detected in the anterior pituitary in proximity with endocrine cells; however, the source of these fibers is unknown (32).…”

Section: Discussionmentioning

confidence: 93%

Ionotropic glutamate receptor activation increases intracellular calcium in prolactin-releasing cells of the adenohypophysis

Bellinger

Fox

Chan

et al. 2006

American Journal of Physiology-Endocrinology and Metabolism

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crine cells of the anterior pituitary are controlled by the central nervous system through hormonal interactions and are not believed to receive direct synaptic connections from the brain. Studies suggest that some pituitary cells may be modulated by the neurotransmitter glutamate (5, 16). We investigated prolactin (PRL)-releasing cells of the anterior pituitary of a euryhaline fish, the tilapia (Oreochromis mossambicus), for the presence of possible glutamate receptors (GluRs). Fura-2 imaging addressed the ability of glutamate to increase intracellular calcium. We observed a dose-dependent increase in intracellular calcium with transient perfusion (1-2 min) of glutamate (10 nM to 1 mM) in two-thirds of imaged cells. This increase was attenuated by the ionotropic GluR antagonist kynurenic acid (0.5-1.0 mM). The increase was also blocked or attenuated by antagonists of L-type voltage-gated calcium channels. The GluR agonist ␣-amino-3-hydroxy-5-methylisoxazole propionic acid (AMPA; 100 M) produced intracellular calcium increases that were reversibly blocked by the selective AMPA antagonist 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX). In contrast, the selective agonist N-methyl-D-aspartate (NMDA; 100 M to 1 mM in magnesium-free solution with 10 M glycine) had no effect on intracellular calcium. Radioimmunoassays demonstrated that glutamate stimulated PRL release. CNQX but not the NMDA receptor antagonist 2-amino-5-phosphonovaleric acid blocked this release. Antibodies for mammalian AMPA-and NMDAtype GluR produced a similar punctate immunoreactivity in the periphery of PRL cells. However, the NMDA antibody recognized a protein of a different molecular mass in PRL cells compared with brain cells. These results clearly indicate the presence of GluRs on tilapia PRL cells that can stimulate PRL release.pituitary; endocrine; osmoregulation; calcium imaging; radioimmunoassay THE ANTERIOR PITUITARY, or adenohypophysis, is derived from nonneuronal epithelial tissue that fuses during embryonic development with the neural crest-derived neurohypophysis (posterior pituitary) (17). Cells of the adenohypophysis release a variety of peptide hormones involved in growth, stress, metabolism, and sexual differentiation and function. In mammals, a complex portal system of capillaries carries blood and signaling molecules between the neurohypophysis and adenohypophysis. In teleost fish, this system is limited to a thin wall of capillaries between the anterior and intermediate lobes. The portal system brings hormones and releasing factors to cells of the anterior pituitary from neurosecretory cells in the hypothalamus. In addition, it carries hormones released from pituitary cells to the circulation.The major excitatory neurotransmitter in the vertebrate central nervous system is the amino acid glutamate. Recent research suggests that many nonneuronal cells also have glutamate receptors (16). Although glutamatergic innervation of endocrine cells of the anterior pituitary has not been described, growing evidence suggests that glutamate ca...

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“…Ball and Baker, 1969;Sage and Bern, 1972). Electron microscope studies show th a t types A and B axons make direct contact with both cell types.…”

Section: Discussionmentioning

confidence: 99%

“…Ball and Baker, 1969;Sage and Bern, 1972). The PbH + cells appear to secrete MSH, whereas th e PbH -cells have an uncertain function, possibly related to osmoregulation (Olivereau and Ball, 1970).…”

Section: Introductionmentioning

confidence: 99%

Preliminary report on the effect of pituitary autotransplantation on the pars intermedia of the seawater goby, Gillichthys mirabilis

Nishioka¹,

Nagahama²,

Bern³

1973

Bol. Zool. Biol. Mar.

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RESUMOE studou-se com a microscopía eletrônica os efeitos do autotransplante da parte interm édia da pituitaria do cadoz de água salgada, GiUichthys m irabilis.N o peixe sem transplante, a parte interm édia possui dois tipos de células secretoras: hem atoxilina de Pb-positiva (P bH +) e hem atoxilina de chumbo negativa (P b H -), diretam ente inervadas pelos axónios neurossecretores (tipo A e B) originarios do hipotálam o.Após o autotransplante, a parte interm édia revasculariza-se ra pidam ente e urna sem ana após o transplante as células PbH+ pos suem pequeno núm ero de grânulos secretores, retículo endoplasmá-tico tortuoso e bem desenvolvido. Depois de quatro sem anas as células

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Cytophysiology of the Teleost Pituitary

Cited by 82 publications

References 203 publications

Interrelationships between thyroidal and reproductive endocrine systems in fish

Interrelationships between thyroidal and reproductive endocrine systems in fish

Ionotropic glutamate receptor activation increases intracellular calcium in prolactin-releasing cells of the adenohypophysis

Preliminary report on the effect of pituitary autotransplantation on the pars intermedia of the seawater goby, Gillichthys mirabilis

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