Oestradiol enhances plasma growth hormone and insulin-like growth factor-I concentrations and increased the expression of their receptors mRNAs in the liver of ovariectomized cows

Colak, M.; Shimizu, T.; Matsunaga, N.; Murayama, C.; Nagashima, S.; Kataoka, M.; Kawashima, C.; Matsui, M.; van Dorland, H.A.; Bruckmaier, R.M.; Miyamoto, A. (2011). Oestradiol enhances plasma growth hormone and insulin-like growth factor-I concentrations and increased the expression of their receptors mRNAs in the liver of ovariectomized cows. Reproduction in domestic animals, 46(5), pp. 854-61. Berlin: Blackwell 10.1111/j.1439-0531.2011.01754.x

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Many metabolic hormones, growth hormone (GH), insulin-like growth factor-I (IGF-I) and insulin affect ovarian functions. However, whether ovarian steroid hormones affect metabolic hormones in cattle remains unknown. This study aimed to determine the effect of sex steroids on the plasma profiles of GH, IGF-I and insulin and their receptors in the liver and adipose tissues of dairy cows. Ovariectomized cows (n = 14) were randomly divided into four groups: control group (n = 3) was treated with saline on Day 0; oestradiol (E2) group (n = 3), with saline and 1 mg oestradiol benzoate (EB) on Day 0 and 5, respectively; progesterone (P4) group (n = 4) with two CIDRs (Pfizer Inc., Tokyo, Japan) from Day 0; and E2 + P4 group (n = 4) with two CIDRs on Day 0 that were removed on Day 6 and were immediately injected with 1 mg EB. The animals were euthanized after the experiment, and liver and adipose tissues samples were quantitatively analysed using real-time PCR for the expression of mRNA for the GH (GHR), IGF-I (IGFR-I) and insulin (IR) receptor mRNAs. Oestradiol benzoate significantly increased the number of peaks (p < 0.05), pulse amplitude (p < 0.05) and area under the curve (AUC; p < 0.01) for plasma GH; moreover, it increased plasma IGF-I concentration (p < 0.05), but it had no effect on the plasma insulin profile. P4 significantly decreased the AUC (p < 0.01), compared with the control group, whereas it did not affect the number of peaks and the amplitude of GH pulses. P4 + E2 did not affect the GH pulse profile. E2 increased the mRNA expression of GHR, IGFR-I and IR in the liver (p < 0.05), whereas both P4 and E2 + P4 did not change their expressions. Our results provide evidence that the metabolic and reproductive endocrine axes may regulate each other to ensure optimal reproductive and metabolic function.

Item Type:

Journal Article (Original Article)

Division/Institute:

05 Veterinary Medicine > Department of Clinical Research and Veterinary Public Health (DCR-VPH) > Veterinary Physiology

UniBE Contributor:

van Dorland, Hendrika Anette and Bruckmaier, Rupert

ISSN:

0936-6768

Publisher:

Blackwell

Language:

English

Submitter:

Factscience Import

Date Deposited:

04 Oct 2013 14:31

Last Modified:

21 Jan 2014 15:04

Publisher DOI:

10.1111/j.1439-0531.2011.01754.x

Web of Science ID:

000295087300016

URI:

https://boris.unibe.ch/id/eprint/12148 (FactScience: 218436)

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