NUTRITIONAL REGULATION OF CELL AND ORGAN GROWTH, DIFFERENTIATION, AND DEVELOPMENT
Location: Children Nutrition Research Center (Houston, Tx)
Title: Glucagon-like peptide-2 increases splanchnic blood flow acutely in calves but loses effectiveness with chronic exposure
Submitted to: Joint Meeting of the ADSA, AMSA, ASAS and PSA
Publication Type: Abstract Only
Publication Acceptance Date: May 1, 2009
Publication Date: July 1, 2009
Citation: Taylor, C.C., Burrin, D.G., Holst, J.J., Mcleod, K.R., Harmon, D.L. 2009. Glucagon-like peptide-2 increases splanchnic blood flow acutely in calves but loses effectiveness with chronic exposure. Joint Meeting of the ADSA, AMSA, ASAS and PSA. Journal of Animal Science. 87:234 (E-Suppl. 2).
Glucagon-like peptide-2 (GLP-2) is a 33-amino acid hormone secreted from the gastrointestinal tract that rapidly increases small intestinal blood flow. No experiments have been conducted evaluating the blood flow response to GLP-2 after extended administration, nor have investigations been performed in ruminants. Eight Holstein calves with an ultrasonic flow probe around the superior mesenteric artery (SMA) and catheters in the carotid artery, mesenteric vein, portal vein, and hepatic vein were paired by age and randomly assigned to treatment: vehicle (0.5% BSA in saline; n= 4) or GLP-2 (50 ug/kg BW bovine GLP-2 in vehicle; n= 4). Treatments were administered by subcutaneous injection every 12 h for 10 d. Calves were fed a 50:50 (DM basis) mixture of alfalfa cubes and calf starter at 2.75% of BW in 2 daily meals. A blood flow experiment was conducted on d 0 (Acute) and d 10 (Chronic) of administration and consisted of 3 periods: baseline saline infusion (30 min) to establish baseline blood flow, treatment infusion in which calves were infused with their assigned treatment, either BSA or GLP-2 (1000 pmol/kg/h) for 60 min, and saline infusion (60 min) to observe the recovery of blood flow after treatment infusion. Portal and hepatic blood flows were measured by p-aminohippurate dilution. Infusion of GLP-2 increased SMA blood flow to 175% of baseline on d 0 but to only 137% of baseline after Chronic treatment (interaction, P=0.0002). Similar trends were observed for portal and hepatic plasma flow. Our results show that GLP-2 increases splanchnic blood flow in ruminants but this response is attenuated after 10-d GLP-2 administration. These results suggest that GLP-2 could modulate nutrient absorption in ruminants through effects on splanchnic blood flow.