The Experts below are selected from a list of 51 Experts worldwide ranked by ideXlab platform
Carlos Villalobos - One of the best experts on this subject based on the ideXlab platform.
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Changes in expression of Hypothalamic Releasing Hormone receptors in individual rat anterior pituitary cells during maturation, puberty and senescence.
Endocrinology, 2005Co-Authors: Laura Senovilla, Javier García-sancho, Carlos VillalobosAbstract:Anterior pituitary (AP) is formed by five different cell types, each one producing a different AP Hormone whose secretion is regulated by a specific Hypothalamic-Releasing Hormone (HRH). On the other hand, a significant number of AP cells express multiple HRH receptors (multiresponsive cells). Plastic changes in expression of HRH receptors in individual AP cells are involved in critical endocrine events. Here we have characterized the changes in functional responses to CRH, LHRH, TRH, and GHRH in individual AP cells throughout the wholelifespanoftherat.Tothisend,calciumresponsestothe HRHs were followed by single-cell imaging in freshly dispersed AP cells prepared from rats of different ages (0–540 postnatal days). Three different cell pools were identified: 1) monoresponsive cells, holding a single class of HRH receptor; 2) multiresponsive cells; and 3) nonresponsive cells. The relative abundance of each pool changed with age. Nonresponsive cells were abundant at birth, multiresponsive cells were abundant at puberty, and monoresponsive cells dominated at senescence. The relative abundance of each HRH receptor changed largely with age but not gender. In addition, the contribution of monoresponsive and multiresponsive cells to responsestoeachHRHchangedverymuchwithage.Thus,the anterior pituitary shows large changes in cell populations typed by functional responses to HRHs during maturation, puberty,andsenescence.(Endocrinology146:4627–4634,2005)
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Multifunctional Cells in Human Pituitary Adenomas: Implications for Paradoxical Secretion and Tumorigenesis
The Journal of Clinical Endocrinology and Metabolism, 2004Co-Authors: Laura Senovilla, Javier García-sancho, Lucía Núñez, José María De Campos, D.a. De Luis, Enrique Romero, Ana Sánchez, Carlos VillalobosAbstract:Pituitary adenomas are very common in humans. They are of monoclonal origin, very heterogeneous, and produce frequently paradoxical secretion. The normal anterior pituitary (AP) contains some unorthodox multifunctional cells able to store more than one AP Hormone (polyhormonal) and/or to express multiple Hypothalamic-Releasing Hormone receptors (multiresponsive). Multifunctional AP cells seem to be involved in plasticity processes such as transdifferentiation or paradoxical secretion. Here, we have characterized the single-cell phenotypes of 15 human pituitary tumors, including prolactinomas, nonfunctioning adenomas, and adenomas from multiple endocrine neoplasia type I (MEN-I) and pituitary Cushing’s disease patients. Individual tumor cells were typed according to expression of AP Hormones and Hypothalamic-Releasing Hormone receptors by combination of calcium imaging and multiple sequential immunocytochemistry in the same cells. We found a large heterogeneity among the different tumors. In eight of the 1...
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Anterior pituitary thyrotropes are multifunctional cells.
American Journal of Physiology-endocrinology and Metabolism, 2004Co-Authors: Carlos Villalobos, Lucía Núñez, Javier García-sanchoAbstract:Anterior pituitary (AP) contains some unorthodox multifunctional cells that store and secrete two different AP Hormones (polyhormonal cells) and/or respond to several Hypothalamic-Releasing Hormone...
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Multi-responsiveness of single anterior pituitary cells to Hypothalamic-Releasing Hormones: A cellular basis for paradoxical secretion
Proceedings of the National Academy of Sciences of the United States of America, 1997Co-Authors: Carlos Villalobos, Javier García-sancho, Lucía Núñez, Frawley Ls, Ana SánchezAbstract:The classic view for Hypothalamic regulation of anterior pituitary (AP) Hormone secretion holds that release of each AP Hormone is controlled specifically by a corresponding Hypothalamic-Releasing Hormone (HRH). In this scenario, binding of a given HRH (thyrotropin-, growth Hormone-, corticotropin-, and luteinizing Hormone-Releasing Hormones) to specific receptors in its target cell increases the concentration of cytosolic Ca2+ ([Ca2+]i), thereby selectively stimulating the release of the appropriate Hormone. However, “paradoxical” responses of AP cells to the four well-established HRHs have been observed repeatedly with both in vivo and in vitro systems, raising the possibility of functional overlap between the different AP cell types. To explore this possibility, we evaluated the effects of HRHs on [Ca2+]i in single AP cells identified immunocytochemically by the Hormone they stored. We found that each of the five major AP cell types contained discrete subpopulations that were able to respond to several HRHs. The relative abundance of these multi-responsive cells was 59% for lactotropes, 33% for thyrotropes, and in the range of 47–55% for gonadotropes, corticotropes, and somatotropes. Analysis of prolactin release from single living cells revealed that each of the four HRHs tested were able to induce Hormone release from a discrete lactotrope subpopulation, the size of which corresponded closely to that in which [Ca2+]i changes were induced by the same secretagogues. When viewed as a whole, our diverse functional measurements of multi-responsiveness suggest that Hypothalamic control of pituitary function is more complicated than previously envisioned. Moreover, they provide a cellular basis for the so-called “paradoxical” behavior of pituitary cells to Hypothalamic hypophysiotropic agents.
Javier García-sancho - One of the best experts on this subject based on the ideXlab platform.
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Changes in expression of Hypothalamic Releasing Hormone receptors in individual rat anterior pituitary cells during maturation, puberty and senescence.
Endocrinology, 2005Co-Authors: Laura Senovilla, Javier García-sancho, Carlos VillalobosAbstract:Anterior pituitary (AP) is formed by five different cell types, each one producing a different AP Hormone whose secretion is regulated by a specific Hypothalamic-Releasing Hormone (HRH). On the other hand, a significant number of AP cells express multiple HRH receptors (multiresponsive cells). Plastic changes in expression of HRH receptors in individual AP cells are involved in critical endocrine events. Here we have characterized the changes in functional responses to CRH, LHRH, TRH, and GHRH in individual AP cells throughout the wholelifespanoftherat.Tothisend,calciumresponsestothe HRHs were followed by single-cell imaging in freshly dispersed AP cells prepared from rats of different ages (0–540 postnatal days). Three different cell pools were identified: 1) monoresponsive cells, holding a single class of HRH receptor; 2) multiresponsive cells; and 3) nonresponsive cells. The relative abundance of each pool changed with age. Nonresponsive cells were abundant at birth, multiresponsive cells were abundant at puberty, and monoresponsive cells dominated at senescence. The relative abundance of each HRH receptor changed largely with age but not gender. In addition, the contribution of monoresponsive and multiresponsive cells to responsestoeachHRHchangedverymuchwithage.Thus,the anterior pituitary shows large changes in cell populations typed by functional responses to HRHs during maturation, puberty,andsenescence.(Endocrinology146:4627–4634,2005)
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Multifunctional Cells in Human Pituitary Adenomas: Implications for Paradoxical Secretion and Tumorigenesis
The Journal of Clinical Endocrinology and Metabolism, 2004Co-Authors: Laura Senovilla, Javier García-sancho, Lucía Núñez, José María De Campos, D.a. De Luis, Enrique Romero, Ana Sánchez, Carlos VillalobosAbstract:Pituitary adenomas are very common in humans. They are of monoclonal origin, very heterogeneous, and produce frequently paradoxical secretion. The normal anterior pituitary (AP) contains some unorthodox multifunctional cells able to store more than one AP Hormone (polyhormonal) and/or to express multiple Hypothalamic-Releasing Hormone receptors (multiresponsive). Multifunctional AP cells seem to be involved in plasticity processes such as transdifferentiation or paradoxical secretion. Here, we have characterized the single-cell phenotypes of 15 human pituitary tumors, including prolactinomas, nonfunctioning adenomas, and adenomas from multiple endocrine neoplasia type I (MEN-I) and pituitary Cushing’s disease patients. Individual tumor cells were typed according to expression of AP Hormones and Hypothalamic-Releasing Hormone receptors by combination of calcium imaging and multiple sequential immunocytochemistry in the same cells. We found a large heterogeneity among the different tumors. In eight of the 1...
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Anterior pituitary thyrotropes are multifunctional cells.
American Journal of Physiology-endocrinology and Metabolism, 2004Co-Authors: Carlos Villalobos, Lucía Núñez, Javier García-sanchoAbstract:Anterior pituitary (AP) contains some unorthodox multifunctional cells that store and secrete two different AP Hormones (polyhormonal cells) and/or respond to several Hypothalamic-Releasing Hormone...
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Multi-responsiveness of single anterior pituitary cells to Hypothalamic-Releasing Hormones: A cellular basis for paradoxical secretion
Proceedings of the National Academy of Sciences of the United States of America, 1997Co-Authors: Carlos Villalobos, Javier García-sancho, Lucía Núñez, Frawley Ls, Ana SánchezAbstract:The classic view for Hypothalamic regulation of anterior pituitary (AP) Hormone secretion holds that release of each AP Hormone is controlled specifically by a corresponding Hypothalamic-Releasing Hormone (HRH). In this scenario, binding of a given HRH (thyrotropin-, growth Hormone-, corticotropin-, and luteinizing Hormone-Releasing Hormones) to specific receptors in its target cell increases the concentration of cytosolic Ca2+ ([Ca2+]i), thereby selectively stimulating the release of the appropriate Hormone. However, “paradoxical” responses of AP cells to the four well-established HRHs have been observed repeatedly with both in vivo and in vitro systems, raising the possibility of functional overlap between the different AP cell types. To explore this possibility, we evaluated the effects of HRHs on [Ca2+]i in single AP cells identified immunocytochemically by the Hormone they stored. We found that each of the five major AP cell types contained discrete subpopulations that were able to respond to several HRHs. The relative abundance of these multi-responsive cells was 59% for lactotropes, 33% for thyrotropes, and in the range of 47–55% for gonadotropes, corticotropes, and somatotropes. Analysis of prolactin release from single living cells revealed that each of the four HRHs tested were able to induce Hormone release from a discrete lactotrope subpopulation, the size of which corresponded closely to that in which [Ca2+]i changes were induced by the same secretagogues. When viewed as a whole, our diverse functional measurements of multi-responsiveness suggest that Hypothalamic control of pituitary function is more complicated than previously envisioned. Moreover, they provide a cellular basis for the so-called “paradoxical” behavior of pituitary cells to Hypothalamic hypophysiotropic agents.
Lucía Núñez - One of the best experts on this subject based on the ideXlab platform.
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Multifunctional Cells in Human Pituitary Adenomas: Implications for Paradoxical Secretion and Tumorigenesis
The Journal of Clinical Endocrinology and Metabolism, 2004Co-Authors: Laura Senovilla, Javier García-sancho, Lucía Núñez, José María De Campos, D.a. De Luis, Enrique Romero, Ana Sánchez, Carlos VillalobosAbstract:Pituitary adenomas are very common in humans. They are of monoclonal origin, very heterogeneous, and produce frequently paradoxical secretion. The normal anterior pituitary (AP) contains some unorthodox multifunctional cells able to store more than one AP Hormone (polyhormonal) and/or to express multiple Hypothalamic-Releasing Hormone receptors (multiresponsive). Multifunctional AP cells seem to be involved in plasticity processes such as transdifferentiation or paradoxical secretion. Here, we have characterized the single-cell phenotypes of 15 human pituitary tumors, including prolactinomas, nonfunctioning adenomas, and adenomas from multiple endocrine neoplasia type I (MEN-I) and pituitary Cushing’s disease patients. Individual tumor cells were typed according to expression of AP Hormones and Hypothalamic-Releasing Hormone receptors by combination of calcium imaging and multiple sequential immunocytochemistry in the same cells. We found a large heterogeneity among the different tumors. In eight of the 1...
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Anterior pituitary thyrotropes are multifunctional cells.
American Journal of Physiology-endocrinology and Metabolism, 2004Co-Authors: Carlos Villalobos, Lucía Núñez, Javier García-sanchoAbstract:Anterior pituitary (AP) contains some unorthodox multifunctional cells that store and secrete two different AP Hormones (polyhormonal cells) and/or respond to several Hypothalamic-Releasing Hormone...
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Multi-responsiveness of single anterior pituitary cells to Hypothalamic-Releasing Hormones: A cellular basis for paradoxical secretion
Proceedings of the National Academy of Sciences of the United States of America, 1997Co-Authors: Carlos Villalobos, Javier García-sancho, Lucía Núñez, Frawley Ls, Ana SánchezAbstract:The classic view for Hypothalamic regulation of anterior pituitary (AP) Hormone secretion holds that release of each AP Hormone is controlled specifically by a corresponding Hypothalamic-Releasing Hormone (HRH). In this scenario, binding of a given HRH (thyrotropin-, growth Hormone-, corticotropin-, and luteinizing Hormone-Releasing Hormones) to specific receptors in its target cell increases the concentration of cytosolic Ca2+ ([Ca2+]i), thereby selectively stimulating the release of the appropriate Hormone. However, “paradoxical” responses of AP cells to the four well-established HRHs have been observed repeatedly with both in vivo and in vitro systems, raising the possibility of functional overlap between the different AP cell types. To explore this possibility, we evaluated the effects of HRHs on [Ca2+]i in single AP cells identified immunocytochemically by the Hormone they stored. We found that each of the five major AP cell types contained discrete subpopulations that were able to respond to several HRHs. The relative abundance of these multi-responsive cells was 59% for lactotropes, 33% for thyrotropes, and in the range of 47–55% for gonadotropes, corticotropes, and somatotropes. Analysis of prolactin release from single living cells revealed that each of the four HRHs tested were able to induce Hormone release from a discrete lactotrope subpopulation, the size of which corresponded closely to that in which [Ca2+]i changes were induced by the same secretagogues. When viewed as a whole, our diverse functional measurements of multi-responsiveness suggest that Hypothalamic control of pituitary function is more complicated than previously envisioned. Moreover, they provide a cellular basis for the so-called “paradoxical” behavior of pituitary cells to Hypothalamic hypophysiotropic agents.
Laura Senovilla - One of the best experts on this subject based on the ideXlab platform.
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Changes in expression of Hypothalamic Releasing Hormone receptors in individual rat anterior pituitary cells during maturation, puberty and senescence.
Endocrinology, 2005Co-Authors: Laura Senovilla, Javier García-sancho, Carlos VillalobosAbstract:Anterior pituitary (AP) is formed by five different cell types, each one producing a different AP Hormone whose secretion is regulated by a specific Hypothalamic-Releasing Hormone (HRH). On the other hand, a significant number of AP cells express multiple HRH receptors (multiresponsive cells). Plastic changes in expression of HRH receptors in individual AP cells are involved in critical endocrine events. Here we have characterized the changes in functional responses to CRH, LHRH, TRH, and GHRH in individual AP cells throughout the wholelifespanoftherat.Tothisend,calciumresponsestothe HRHs were followed by single-cell imaging in freshly dispersed AP cells prepared from rats of different ages (0–540 postnatal days). Three different cell pools were identified: 1) monoresponsive cells, holding a single class of HRH receptor; 2) multiresponsive cells; and 3) nonresponsive cells. The relative abundance of each pool changed with age. Nonresponsive cells were abundant at birth, multiresponsive cells were abundant at puberty, and monoresponsive cells dominated at senescence. The relative abundance of each HRH receptor changed largely with age but not gender. In addition, the contribution of monoresponsive and multiresponsive cells to responsestoeachHRHchangedverymuchwithage.Thus,the anterior pituitary shows large changes in cell populations typed by functional responses to HRHs during maturation, puberty,andsenescence.(Endocrinology146:4627–4634,2005)
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Multifunctional Cells in Human Pituitary Adenomas: Implications for Paradoxical Secretion and Tumorigenesis
The Journal of Clinical Endocrinology and Metabolism, 2004Co-Authors: Laura Senovilla, Javier García-sancho, Lucía Núñez, José María De Campos, D.a. De Luis, Enrique Romero, Ana Sánchez, Carlos VillalobosAbstract:Pituitary adenomas are very common in humans. They are of monoclonal origin, very heterogeneous, and produce frequently paradoxical secretion. The normal anterior pituitary (AP) contains some unorthodox multifunctional cells able to store more than one AP Hormone (polyhormonal) and/or to express multiple Hypothalamic-Releasing Hormone receptors (multiresponsive). Multifunctional AP cells seem to be involved in plasticity processes such as transdifferentiation or paradoxical secretion. Here, we have characterized the single-cell phenotypes of 15 human pituitary tumors, including prolactinomas, nonfunctioning adenomas, and adenomas from multiple endocrine neoplasia type I (MEN-I) and pituitary Cushing’s disease patients. Individual tumor cells were typed according to expression of AP Hormones and Hypothalamic-Releasing Hormone receptors by combination of calcium imaging and multiple sequential immunocytochemistry in the same cells. We found a large heterogeneity among the different tumors. In eight of the 1...
Ana Sánchez - One of the best experts on this subject based on the ideXlab platform.
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Multifunctional Cells in Human Pituitary Adenomas: Implications for Paradoxical Secretion and Tumorigenesis
The Journal of Clinical Endocrinology and Metabolism, 2004Co-Authors: Laura Senovilla, Javier García-sancho, Lucía Núñez, José María De Campos, D.a. De Luis, Enrique Romero, Ana Sánchez, Carlos VillalobosAbstract:Pituitary adenomas are very common in humans. They are of monoclonal origin, very heterogeneous, and produce frequently paradoxical secretion. The normal anterior pituitary (AP) contains some unorthodox multifunctional cells able to store more than one AP Hormone (polyhormonal) and/or to express multiple Hypothalamic-Releasing Hormone receptors (multiresponsive). Multifunctional AP cells seem to be involved in plasticity processes such as transdifferentiation or paradoxical secretion. Here, we have characterized the single-cell phenotypes of 15 human pituitary tumors, including prolactinomas, nonfunctioning adenomas, and adenomas from multiple endocrine neoplasia type I (MEN-I) and pituitary Cushing’s disease patients. Individual tumor cells were typed according to expression of AP Hormones and Hypothalamic-Releasing Hormone receptors by combination of calcium imaging and multiple sequential immunocytochemistry in the same cells. We found a large heterogeneity among the different tumors. In eight of the 1...
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Multi-responsiveness of single anterior pituitary cells to Hypothalamic-Releasing Hormones: A cellular basis for paradoxical secretion
Proceedings of the National Academy of Sciences of the United States of America, 1997Co-Authors: Carlos Villalobos, Javier García-sancho, Lucía Núñez, Frawley Ls, Ana SánchezAbstract:The classic view for Hypothalamic regulation of anterior pituitary (AP) Hormone secretion holds that release of each AP Hormone is controlled specifically by a corresponding Hypothalamic-Releasing Hormone (HRH). In this scenario, binding of a given HRH (thyrotropin-, growth Hormone-, corticotropin-, and luteinizing Hormone-Releasing Hormones) to specific receptors in its target cell increases the concentration of cytosolic Ca2+ ([Ca2+]i), thereby selectively stimulating the release of the appropriate Hormone. However, “paradoxical” responses of AP cells to the four well-established HRHs have been observed repeatedly with both in vivo and in vitro systems, raising the possibility of functional overlap between the different AP cell types. To explore this possibility, we evaluated the effects of HRHs on [Ca2+]i in single AP cells identified immunocytochemically by the Hormone they stored. We found that each of the five major AP cell types contained discrete subpopulations that were able to respond to several HRHs. The relative abundance of these multi-responsive cells was 59% for lactotropes, 33% for thyrotropes, and in the range of 47–55% for gonadotropes, corticotropes, and somatotropes. Analysis of prolactin release from single living cells revealed that each of the four HRHs tested were able to induce Hormone release from a discrete lactotrope subpopulation, the size of which corresponded closely to that in which [Ca2+]i changes were induced by the same secretagogues. When viewed as a whole, our diverse functional measurements of multi-responsiveness suggest that Hypothalamic control of pituitary function is more complicated than previously envisioned. Moreover, they provide a cellular basis for the so-called “paradoxical” behavior of pituitary cells to Hypothalamic hypophysiotropic agents.