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The number of lactotrophs is reduced in the anterior pituitary of streptozotocin-induced diabetic rats

The number of lactotrophs is reduced in the anterior pituitary of streptozotocin-induced diabetic... A.I. Arroba et al.: Reduction in number of lactotrophs A.I. Arroba L. M. Frago C. Pañeda J. Argente J. A. Chowen Dr. jachowen@hotmail.com Unit of Investigation; Department of Endocrinology, University Hospital Niño Jesús, Avenida Menéndez Pelayo, 65, 28009, Madrid, Spain Aims/hypothesis. Prolactin secretion is often reduced in insulin dependent diabetes mellitus, but little is known about the mechanism involved. Since changes in the hormonal environment modulate cell proliferation, death and cellular makeup of the anterior pituitary, we have analysed whether the number of lactotrophs is reduced in diabetic rats. Methods. Streptozotocin induced diabetic rats were maintained hyperglycaemic for 2 months. Pituitary prolactin, growth hormone, Bcl-2, Bax and PCNA concentrations were analysed by western blot analysis. In situ hybridisation was used for quantification of prolactin and growth hormone mRNA containing cells. Cell death was detected by TUNEL labelling, alone and in combination with immunocytochemistry for prolactin or growth hormone. Results. Diabetic rats had fewer lactotrophs ( p <0.01). This was coincident with a decrease in overall protein and prolactin content. An increase in pituitary cell death was found and some of the TUNEL labelling co-localised with prolactin immunostaining. No change in the concentration of Bcl-2 or Bax, proteins implicated in apoptosis, was detected. PCNA content was higher in the pituitaries of diabetic rats, suggesting increased proliferation. Conclusion/interpretation. Anterior pituitary cell turnover is affected in poorly controlled diabetes mellitus. A decrease in the number of lactotrophs, as a result of increased cell death, could underlie, at least in part, the reduction in prolactin secretion observed in diabetic animals. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Diabetologia Springer Journals

The number of lactotrophs is reduced in the anterior pituitary of streptozotocin-induced diabetic rats

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References (10)

Publisher
Springer Journals
Copyright
Copyright © 2003 by Springer-Verlag
Subject
Legacy
ISSN
0012-186X
eISSN
1432-0428
DOI
10.1007/s00125-003-1088-6
pmid
12743699
Publisher site
See Article on Publisher Site

Abstract

A.I. Arroba et al.: Reduction in number of lactotrophs A.I. Arroba L. M. Frago C. Pañeda J. Argente J. A. Chowen Dr. jachowen@hotmail.com Unit of Investigation; Department of Endocrinology, University Hospital Niño Jesús, Avenida Menéndez Pelayo, 65, 28009, Madrid, Spain Aims/hypothesis. Prolactin secretion is often reduced in insulin dependent diabetes mellitus, but little is known about the mechanism involved. Since changes in the hormonal environment modulate cell proliferation, death and cellular makeup of the anterior pituitary, we have analysed whether the number of lactotrophs is reduced in diabetic rats. Methods. Streptozotocin induced diabetic rats were maintained hyperglycaemic for 2 months. Pituitary prolactin, growth hormone, Bcl-2, Bax and PCNA concentrations were analysed by western blot analysis. In situ hybridisation was used for quantification of prolactin and growth hormone mRNA containing cells. Cell death was detected by TUNEL labelling, alone and in combination with immunocytochemistry for prolactin or growth hormone. Results. Diabetic rats had fewer lactotrophs ( p <0.01). This was coincident with a decrease in overall protein and prolactin content. An increase in pituitary cell death was found and some of the TUNEL labelling co-localised with prolactin immunostaining. No change in the concentration of Bcl-2 or Bax, proteins implicated in apoptosis, was detected. PCNA content was higher in the pituitaries of diabetic rats, suggesting increased proliferation. Conclusion/interpretation. Anterior pituitary cell turnover is affected in poorly controlled diabetes mellitus. A decrease in the number of lactotrophs, as a result of increased cell death, could underlie, at least in part, the reduction in prolactin secretion observed in diabetic animals.

Journal

DiabetologiaSpringer Journals

Published: May 1, 2003

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