Insulin-like growth factor type-1 receptor down-regulation associated with dwarfism in Holstein calves

Blum, J W; Elsasser, T H; Greger, D L; Wittenberg, S; de Vries, F; Distl, O (2007). Insulin-like growth factor type-1 receptor down-regulation associated with dwarfism in Holstein calves. Domestic animal endocrinology, 33(3), pp. 245-68. New York, N.Y.: Elsevier 10.1016/j.domaniend.2006.05.007

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Perturbations in endocrine functions can impact normal growth. Endocrine traits were studied in three dwarf calves exhibiting retarded but proportionate growth and four phenotypically normal half-siblings, sired by the same bull, and four unrelated control calves. Plasma 3,5,3'-triiodothyronine and thyroxine concentrations in dwarfs and half-siblings were in the physiological range and responded normally to injected thyroid-releasing hormone. Plasma glucagon concentrations were different (dwarfs, controls>half-siblings; P<0.05). Plasma growth hormone (GH), insulin-like growth factor-1 (IGF-1) and insulin concentrations in the three groups during an 8-h period were similar, but integrated GH concentrations (areas under concentration curves) were different (dwarfs>controls, P<0.02; half-siblings>controls, P=0.08). Responses of GH to xylazine and to a GH-releasing-factor analogue were similar in dwarfs and half-siblings. Relative gene expression of IGF-1, IGF-2, GH receptor (GHR), insulin receptor, IGF-1 type-1 and -2 receptors (IGF-1R, IGF-2R), and IGF binding proteins were measured in liver and anconeus muscle. GHR mRNA levels were different in liver (dwarfs<controls, P<0.002; dwarfs<half-siblings, P=0.06; half-siblings<controls, P=0.08) but not in muscle. IGF-1R mRNA abundance in liver in half-siblings and controls was 2.4- and 2.5-fold higher (P=0.003 and P=0.001, respectively) and in muscle tissue was 2.3- and 1.8-fold higher (P=0.01 and P=0.08, respectively) than in dwarfs. Hepatic IGF-1R protein levels (Western blots) in muscle were 2.5-fold higher (P<0.05) and in liver and muscle (quantitative immunohistochemistry) were higher (P<0.02 and P<0.07, respectively) in half-siblings than in dwarfs. The reduced presence of IGF-1R may have been the underlying cause of dwarfism in studied calves.

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:	Blum, Jürg
ISSN:	0739-7240
Publisher:	Elsevier
Language:	English
Submitter:	Factscience Import
Date Deposited:	04 Oct 2013 14:53
Last Modified:	05 Dec 2022 14:16
Publisher DOI:	10.1016/j.domaniend.2006.05.007
PubMed ID:	16829014
Web of Science ID:	000249572300001
URI:	https://boris.unibe.ch/id/eprint/22713 (FactScience: 36157)