HOME HELP CONTACT US SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Conlon, M A Articles by Ballard, F J Search for Related Content PubMed PubMed Citation Articles by Conlon, M A Articles by Ballard, F J

We have tested whether an animal with substantial amounts of both IGF-I and IGF-II in circulation, such as the guinea pig, would respond to chronic IGF infusion in the same manner as the adult rat, which has negligible amounts of IGF-II in blood. Female guinea pigs of 350 g body weight were continuously infused for 7 days with recombinant guinea pig IGF-I or -II (120 or 360 µg/day) or long R³ IGF-I (LR³IGF-I) (120 µg/day), an analogue which has much reduced affinities for IGF binding proteins. IGF-I or IGF-II infusion led to substantial increases in plasma IGF-I or IGF-II respectively in comparison with vehicle-infused animals. Nevertheless, body weight gain, feed intake, feed conversion efficiency and carcass composition were not significantly affected by any treatment (significance was deemed to be P<0·05). Amongst the tissues examined only the fractional weight (g/kg body weight) of the adrenals was increased, and that only by the higher dose (360 µg/day) of IGF-I. However, the fractional weight of adrenals, gut, kidneys and spleen were significantly increased by LR³IGF-I, but again overall growth was not stimulated. A possible explanation for the lack of IGF-I effects is that total circulating IGF concentrations were not increased by these treatments. IGF-II significantly raised total IGF concentrations at the higher dose only. Plasma IGF-I was reduced by IGF-II infusion, as was plasma IGF-II by IGF-I infusion. LR³IGF-I treatment lowered both plasma IGF-I and IGF-II concentrations, a response probably related to a reduction in total plasma IGF binding protein (IGFBP), especially IGFBP-3, concentrations. We conclude that although the guinea pig is responsive to IGF treatment, the effects differ markedly from those elicited in rats.

Journal of Endocrinology (1995) 146, 247–253

This article has been cited by other articles:

				A. HOEFLICH, M. M. WEBER, T. FISCH, S. NEDBAL, C. FOTTNER, M. W. ELMLINGER, R. WANKE, and E. WOLF Insulin-like growth factor binding protein 2 (IGFBP-2) separates hypertrophic and hyperplastic effects of growth hormone (GH)/IGF-I excess on adrenocortical cells in vivo FASEB J, November 1, 2002; 16(13): 1721 - 1731. [Abstract] [Full Text] [PDF]

				H. M. Khandwala, I. E. McCutcheon, A. Flyvbjerg, and K. E. Friend The Effects of Insulin-Like Growth Factors on Tumorigenesis and Neoplastic Growth Endocr. Rev., June 1, 2000; 21(3): 215 - 244. [Abstract] [Full Text]