Differential radiosensitivity of hypothalamo-pituitary function in the young adult rat.

2.50
Hdl Handle:
http://hdl.handle.net/10541/84149
Title:
Differential radiosensitivity of hypothalamo-pituitary function in the young adult rat.
Authors:
Robinson, Iain C; Fairhall, K M; Hendry, Jolyon H; Shalet, Stephen M
Abstract:
Cranial irradiation in children and adults often results in irreversible hypopituitarism. The earliest and most common endocrine abnormality is GH deficiency, often followed by other pituitary hormone deficits. We investigated whether a similar pattern of progressive hypopituitarism could be reproduced in an animal model. Different doses of cranial irradiation were delivered to the hypothalamo-pituitary region of normal adult male rats, and the effects on their subsequent growth, pituitary weight and hormone contents were studied. Animals received cranial irradiation with 300 kV X-rays at doses of 0, 20, 22 or 24 Gy (n=15 per group) and five animals from each group were killed at 8, 14 or 20 weeks after irradiation. Their anterior pituitary glands were weighed and assayed for GH, LH, TSH, ACTH and prolactin (PRL) content. All three doses of irradiation reduced body weight compared with that in non-irradiated controls and compromised growth between 8 and 20 weeks. Pituitary weight increased between 8 and 20 weeks in control rats, whereas it decreased significantly in the irradiated animals. Irradiation induced time- and dose-dependent changes in pituitary hormone contents. GH and PRL were most sensitive and decreased by more than 90% after irradiation; TSH contents were unaffected 8 weeks after the lowest dose of irradiation, but were reduced at 14 and 20 weeks. LH and ACTH were the slowest to be affected, and only at the greater doses of radiation. Thus progressive multiple pituitary endocrine deficits can be induced differentially in rats by increasing doses of cranial irradiation. This model should prove useful for defining the sites and mechanisms by which cranial irradiation induces neuroendocrine dysfunction.
Affiliation:
Division of Molecular Neuroendocrinology, National Institute for Medical Research, Mill Hill, London, UK. irobins@nimr.mrc.ac.uk
Citation:
Differential radiosensitivity of hypothalamo-pituitary function in the young adult rat. 2001, 169 (3):519-26 J. Endocrinol.
Journal:
The Journal of Endocrinology
Issue Date:
Jun-2001
URI:
http://hdl.handle.net/10541/84149
PubMed ID:
11375122
Type:
Article
Language:
en
ISSN:
0022-0795
Appears in Collections:
All Christie Publications ; All Paterson Institute for Cancer Research

Full metadata record

DC FieldValue Language
dc.contributor.authorRobinson, Iain Cen
dc.contributor.authorFairhall, K Men
dc.contributor.authorHendry, Jolyon Hen
dc.contributor.authorShalet, Stephen Men
dc.date.accessioned2009-10-13T10:54:21Z-
dc.date.available2009-10-13T10:54:21Z-
dc.date.issued2001-06-
dc.identifier.citationDifferential radiosensitivity of hypothalamo-pituitary function in the young adult rat. 2001, 169 (3):519-26 J. Endocrinol.en
dc.identifier.issn0022-0795-
dc.identifier.pmid11375122-
dc.identifier.urihttp://hdl.handle.net/10541/84149-
dc.description.abstractCranial irradiation in children and adults often results in irreversible hypopituitarism. The earliest and most common endocrine abnormality is GH deficiency, often followed by other pituitary hormone deficits. We investigated whether a similar pattern of progressive hypopituitarism could be reproduced in an animal model. Different doses of cranial irradiation were delivered to the hypothalamo-pituitary region of normal adult male rats, and the effects on their subsequent growth, pituitary weight and hormone contents were studied. Animals received cranial irradiation with 300 kV X-rays at doses of 0, 20, 22 or 24 Gy (n=15 per group) and five animals from each group were killed at 8, 14 or 20 weeks after irradiation. Their anterior pituitary glands were weighed and assayed for GH, LH, TSH, ACTH and prolactin (PRL) content. All three doses of irradiation reduced body weight compared with that in non-irradiated controls and compromised growth between 8 and 20 weeks. Pituitary weight increased between 8 and 20 weeks in control rats, whereas it decreased significantly in the irradiated animals. Irradiation induced time- and dose-dependent changes in pituitary hormone contents. GH and PRL were most sensitive and decreased by more than 90% after irradiation; TSH contents were unaffected 8 weeks after the lowest dose of irradiation, but were reduced at 14 and 20 weeks. LH and ACTH were the slowest to be affected, and only at the greater doses of radiation. Thus progressive multiple pituitary endocrine deficits can be induced differentially in rats by increasing doses of cranial irradiation. This model should prove useful for defining the sites and mechanisms by which cranial irradiation induces neuroendocrine dysfunction.en
dc.language.isoenen
dc.subject.meshAnimals-
dc.subject.meshBody Weight-
dc.subject.meshDisease Models, Animal-
dc.subject.meshDisease Progression-
dc.subject.meshDose-Response Relationship, Radiation-
dc.subject.meshHypopituitarism-
dc.subject.meshHypothalamo-Hypophyseal System-
dc.subject.meshMale-
dc.subject.meshOrgan Size-
dc.subject.meshPituitary Gland, Anterior-
dc.subject.meshPituitary Hormones-
dc.subject.meshRadiation Injuries-
dc.subject.meshRadiation Tolerance-
dc.subject.meshRats-
dc.subject.meshRats, Inbred Strains-
dc.titleDifferential radiosensitivity of hypothalamo-pituitary function in the young adult rat.en
dc.typeArticleen
dc.contributor.departmentDivision of Molecular Neuroendocrinology, National Institute for Medical Research, Mill Hill, London, UK. irobins@nimr.mrc.ac.uken
dc.identifier.journalThe Journal of Endocrinologyen

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