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Annemarie Brüel

Growth hormone increases the proliferation of existing cardiac myocytes and the total number of cardiac myocytes in the rat heart

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Growth hormone increases the proliferation of existing cardiac myocytes and the total number of cardiac myocytes in the rat heart. / Brüel, Annemarie; Christoffersen, Tue E H; Nyengaard, Jens R.

I: Cardiovascular Research, Bind 79, Nr. 3, 2008, s. 400-8.

Publikation: Bidrag til tidsskrift/Konferencebidrag i tidsskrift /Bidrag til avisTidsskriftartikelForskningpeer review

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@article{7ea262d0fce311dda987000ea68e967b,
title = "Growth hormone increases the proliferation of existing cardiac myocytes and the total number of cardiac myocytes in the rat heart",
abstract = "OBJECTIVE: Growth hormone (GH) is known to induce growth of the normal rat heart. Whether this growth is due solely to hypertrophy of the cardiac myocytes or whether a concomitant hyperplasia of the cardiac myocytes also takes place is currently not known. Therefore, the aim of the present study was to investigate whether GH induces hyperplasia in the left ventricle (LV) of sexually mature rats. METHODS: Three-month-old female Wistar rats were injected with GH (5 mg/kg/d) for 80 days, whereas a control group was injected with saline. Before perfusion-fixation, haemodynamic measurements were obtained. Isotropic, uniformly random sections were cut from the isolated LV, and the total number of myocyte nuclei and the average number of nuclei per myocyte were estimated using unbiased stereology. Immunohistochemistry was performed in order to detect proliferation (Ki-67), apoptosis (activated caspase-3), and stem cells (c-kit). RESULTS: GH increased the total number of cardiac myocytes by 33% [GH: 25.7 x 10(6) (0.09), controls: 19.3 x 10(6) (0.14), P<0.01, (mean (CV)], and this was accompanied by an increase in the percentage of Ki-67 positive myocytes by 216% [GH: 0.0179% (0.65), controls: 0.0057% (1.43), P<0.05]. No significant differences were found for caspase-3 positive or c-kit positive myocytes. GH increased insulin-like growth factor I (IGF-I) content of the myocardial tissue by 754% [GH: 247 ng/g wet weight (0.75), controls: 29 ng/g wet weight (0.58), P<0.01] and the LV wet weight by 50% [GH: 849 mg (0.15), controls: 567 mg (0.07), P<0.001], but did not influence the haemodynamic parameters. CONCLUSION: These results strongly suggest that GH is able to stimulate cardiac myocytes to re-enter the cell cycle, divide, and thereby increase the number of cardiac myocytes in sexually mature rats.",
author = "Annemarie Br{\"u}el and Christoffersen, {Tue E H} and Nyengaard, {Jens R}",
year = "2008",
doi = "10.1016/j.cardiores.2007.06.026",
language = "English",
volume = "79",
pages = "400--8",
journal = "Cardiovascular Research",
issn = "0008-6363",
publisher = "Oxford University Press",
number = "3",

}

RIS

TY - JOUR

T1 - Growth hormone increases the proliferation of existing cardiac myocytes and the total number of cardiac myocytes in the rat heart

AU - Brüel, Annemarie

AU - Christoffersen, Tue E H

AU - Nyengaard, Jens R

PY - 2008

Y1 - 2008

N2 - OBJECTIVE: Growth hormone (GH) is known to induce growth of the normal rat heart. Whether this growth is due solely to hypertrophy of the cardiac myocytes or whether a concomitant hyperplasia of the cardiac myocytes also takes place is currently not known. Therefore, the aim of the present study was to investigate whether GH induces hyperplasia in the left ventricle (LV) of sexually mature rats. METHODS: Three-month-old female Wistar rats were injected with GH (5 mg/kg/d) for 80 days, whereas a control group was injected with saline. Before perfusion-fixation, haemodynamic measurements were obtained. Isotropic, uniformly random sections were cut from the isolated LV, and the total number of myocyte nuclei and the average number of nuclei per myocyte were estimated using unbiased stereology. Immunohistochemistry was performed in order to detect proliferation (Ki-67), apoptosis (activated caspase-3), and stem cells (c-kit). RESULTS: GH increased the total number of cardiac myocytes by 33% [GH: 25.7 x 10(6) (0.09), controls: 19.3 x 10(6) (0.14), P<0.01, (mean (CV)], and this was accompanied by an increase in the percentage of Ki-67 positive myocytes by 216% [GH: 0.0179% (0.65), controls: 0.0057% (1.43), P<0.05]. No significant differences were found for caspase-3 positive or c-kit positive myocytes. GH increased insulin-like growth factor I (IGF-I) content of the myocardial tissue by 754% [GH: 247 ng/g wet weight (0.75), controls: 29 ng/g wet weight (0.58), P<0.01] and the LV wet weight by 50% [GH: 849 mg (0.15), controls: 567 mg (0.07), P<0.001], but did not influence the haemodynamic parameters. CONCLUSION: These results strongly suggest that GH is able to stimulate cardiac myocytes to re-enter the cell cycle, divide, and thereby increase the number of cardiac myocytes in sexually mature rats.

AB - OBJECTIVE: Growth hormone (GH) is known to induce growth of the normal rat heart. Whether this growth is due solely to hypertrophy of the cardiac myocytes or whether a concomitant hyperplasia of the cardiac myocytes also takes place is currently not known. Therefore, the aim of the present study was to investigate whether GH induces hyperplasia in the left ventricle (LV) of sexually mature rats. METHODS: Three-month-old female Wistar rats were injected with GH (5 mg/kg/d) for 80 days, whereas a control group was injected with saline. Before perfusion-fixation, haemodynamic measurements were obtained. Isotropic, uniformly random sections were cut from the isolated LV, and the total number of myocyte nuclei and the average number of nuclei per myocyte were estimated using unbiased stereology. Immunohistochemistry was performed in order to detect proliferation (Ki-67), apoptosis (activated caspase-3), and stem cells (c-kit). RESULTS: GH increased the total number of cardiac myocytes by 33% [GH: 25.7 x 10(6) (0.09), controls: 19.3 x 10(6) (0.14), P<0.01, (mean (CV)], and this was accompanied by an increase in the percentage of Ki-67 positive myocytes by 216% [GH: 0.0179% (0.65), controls: 0.0057% (1.43), P<0.05]. No significant differences were found for caspase-3 positive or c-kit positive myocytes. GH increased insulin-like growth factor I (IGF-I) content of the myocardial tissue by 754% [GH: 247 ng/g wet weight (0.75), controls: 29 ng/g wet weight (0.58), P<0.01] and the LV wet weight by 50% [GH: 849 mg (0.15), controls: 567 mg (0.07), P<0.001], but did not influence the haemodynamic parameters. CONCLUSION: These results strongly suggest that GH is able to stimulate cardiac myocytes to re-enter the cell cycle, divide, and thereby increase the number of cardiac myocytes in sexually mature rats.

U2 - 10.1016/j.cardiores.2007.06.026

DO - 10.1016/j.cardiores.2007.06.026

M3 - Journal article

C2 - 17673190

VL - 79

SP - 400

EP - 408

JO - Cardiovascular Research

JF - Cardiovascular Research

SN - 0008-6363

IS - 3

ER -