QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Purchase Article View Shopping Cart 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 Chelikani, P. K. Articles by Kennelly, J. J. Search for Related Content PubMed PubMed Citation Articles by Chelikani, P. K. Articles by Kennelly, J. J.

---

Nutrient Metabolism

Response of Plasma Leptin Concentration to Jugular Infusion of Glucose or Lipid Is Dependent on the Stage of Lactation of Holstein Cows¹

Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada T6G 2P5; ^* Animal Sciences Department, University of Misssouri, Columbia, MO 65211

²To whom correspondence should be addressed. E-mail: john.kennelly{at}ualberta.ca.

In this study we investigated the hormonal and metabolite responses to isoenergetic jugular infusions of glucose or lipid in early- and late-lactation Holstein cows. Six Holstein cows were used in a replicated Latin square design with jugular infusions of either 1) control (CON; saline), 2) glucose (GLU; 50% dextrose) or 3) lipid (LIP; 20% Intralipid). Treatments did not affect dry matter intake, with the exception of a hypophagic effect of LIP in late lactation. The GLU-induced hyperglycemia and hyperinsulinemia were greater in late-lactation than in early-lactation cows. The GLU treatment did not affect plasma leptin and insulin-like growth factor-1 (IGF-1) concentrations in early-lactation cows, but it increased them in late-lactation cows. The LIP treatment did not affect plasma leptin, insulin and IGF-1 concentrations in early-lactation cows, despite a marked LIP-induced increase in plasma nonesterified fatty acid and ß-hydroxybutyrate concentrations and a reduction in growth hormone (GH) concentration. Compared with the delayed leptin response to GLU, the stimulatory effect of LIP on leptin secretion in late-lactation cows was relatively rapid and occurred in the absence of any significant changes in plasma insulin, IGF-1 or GH. We propose that insulin-mediated glucose metabolism may be involved in the stimulatory effects of glucose on leptin secretion in late-lactation animals but that the stimulatory effects of lipid are independent of insulin or IGF-1. In early-lactation animals a strong inhibitory effect of GH on leptin expression and release, in addition to low adipose reserves and/or energy balance, might override any short-term stimulatory effect of glucose or lipid on leptin secretion.

KEY WORDS: • leptin • glucose • lipid • dairy cows

This article has been cited by other articles:

				M. A. Fowler, C. D. Champagne, D. S. Houser, and D. E. Crocker Hormonal regulation of glucose clearance in lactating northern elephant seals (Mirounga angustirostris) J. Exp. Biol., September 15, 2008; 211(18): 2943 - 2949. [Abstract] [Full Text] [PDF]

				J. A. A. Pires, A. H. Souza, and R. R. Grummer Induction of Hyperlipidemia by Intravenous Infusion of Tallow Emulsion Causes Insulin Resistance in Holstein Cows J Dairy Sci, June 1, 2007; 90(6): 2735 - 2744. [Abstract] [Full Text] [PDF]

				J. L. Martin, R. J. Rasby, D. R. Brink, R. U. Lindquist, D. H. Keisler, and S. D. Kachman Effects of supplementation of whole corn germ on reproductive performance, calf performance, and leptin concentration in primiparous and mature beef cows J Anim Sci, November 1, 2005; 83(11): 2663 - 2670. [Abstract] [Full Text] [PDF]