Hepatic glucocorticoid and α1- and β2-adrenergic receptors in calves change during neonatal maturation and are related to energy regulation.

Schäff, C T; Rohrbeck, D; Steinhoff-Wagner, J; Kanitz, E; Sauerwein, H; Bruckmaier, Rupert; Hammon, H M (2015). Hepatic glucocorticoid and α1- and β2-adrenergic receptors in calves change during neonatal maturation and are related to energy regulation. Journal of dairy science, 98(2), pp. 1046-1056. American Dairy Science Association 10.3168/jds.2014-8636

[img] Text
1-s2.0-S0022030214008480-main.pdf - Published Version
Restricted to registered users only
Available under License Publisher holds Copyright.

Download (626kB) | Request a copy

Catecholamines and glucocorticoids are involved in fetal maturation of organ systems to prepare the fetus for extrauterine life. Calves, especially when born preterm, depend on function of the adrenergic system and the glucocorticoid axis to adapt energy metabolism for the neonatal period. We tested the hypothesis that hepatic glucocorticoid and α1- and β2-adrenergic receptors in neonatal calves are involved in adaptation of energy metabolism around birth and that respective binding capacities depend on stage of maturation during the neonatal period. Calves (n=7 per group) were delivered by section preterm (PT, 9d before term) or were born at term (full-term, FT; spontaneous vaginal delivery), or spontaneously born and fed colostrum for 4d (FTC). Blood samples were taken immediately after birth and before and 2h after feeding at 24h after birth (PT, FT) or on d 4 of life (FTC) to determine metabolic and endocrine changes. After slaughter at 26h after birth (PT, FT) or on d 4 of life (FTC), liver tissue was obtained to measure hepatic binding capacity of glucocorticoid and α1- and β2-adrenergic receptors. Maximal binding capacity and binding affinity were calculated by saturation binding assays using [(3)H]-prazosin and [(3)H]-CGP-12177 for determination of α1- and β2-adrenergic receptors, respectively, and [(3)H]-dexamethasone for determination of glucocorticoid receptor in liver. Additional liver samples were taken to measure mRNA abundance of glucocorticoid and α1- and β2-adrenergic receptors, of key enzymes and factors related to hepatic lipid metabolism, and of insulin-like growth factor 1 (IGF1). Plasma concentrations of β-hydroxybutyrate and leptin changed with time, and leptin concentrations were affected by stage of maturation. The binding capacities for hepatic glucocorticoid and β2-adrenergic receptors as well as gene expression of IGF1 were greater in FTC than in FT and PT, and binding affinity for β2-adrenergic receptor was lowest in PT. The binding capacity of hepatic α1-adrenergic receptor was greatest in FTC and greater in FT than in PT. The binding capacities of glucocorticoid and α1-adrenergic receptors were mainly related to variables of glucose and lipid metabolism. In conclusion, our results indicate dependence of hepatic glucocorticoid and adrenergic receptors on stage of maturation in neonatal calves and emphasize the association of α1-adrenergic receptor and glucocorticoid receptor with neonatal glucose and lipid metabolism.

Item Type:

Journal Article (Original Article)

Division/Institute:

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

UniBE Contributor:

Bruckmaier, Rupert

Subjects:

500 Science > 570 Life sciences; biology

ISSN:

0022-0302

Publisher:

American Dairy Science Association

Language:

English

Submitter:

Lorenzo Enrique Hernandez Castellano

Date Deposited:

20 Jul 2017 12:48

Last Modified:

20 Jul 2017 12:48

Publisher DOI:

10.3168/jds.2014-8636

PubMed ID:

25497806

Uncontrolled Keywords:

adrenergic receptor; calf; development; energy metabolism; glucocorticoid receptor

BORIS DOI:

10.7892/boris.95886

URI:

https://boris.unibe.ch/id/eprint/95886

Actions (login required)

Edit item Edit item
Provide Feedback