Effect of triglycerides on growth hormone (GH)-releasing factor-mediated GH secretion in newborn calves.
The effect of triglycerides (Tg) on GRF-mediated GH secretion was examined in 2 groups of twelve ten-day old male calves. Twelve calves were intravenously infused with a lipid-heparin solution (5 mg Tg and 0.3 IU heparin/kg body wt/min for 90 min). The twelve control calves received in the same way, the same volume of saline. Thirty minutes after the start of infusion, GRF 1-29 (human amide, 0.16 micrograms/kg body wt) was intravenously injected in six animals of each group. Mean plasma GH levels reached peak concentrations in the 2 groups 5 min after GRF injection. However the area under the GH response curve, when lipid-heparin was given, was significantly diminished compared to the response when saline was given. In the same time, lipid-heparin treatment increased plasma SRIF concentration. These data suggest that an increase in plasma Tg concentration, induced by lipid-heparin infusion, inhibits GRF-mediated GH secretion, possibly through stimulation of SRIF secretion.
Coxam
V
V
INRA Theix, Ceyrat, France.
Davicco
M J
MJ
Barlet
J P
JP
D000818:Animals; D000831:Animals, Newborn / Q000097:blood* / Q000378:metabolism; D002417:Cattle / Q000097:blood*; D013006:Growth Hormone / Q000097:blood* / Q000378:metabolism; D013007:Growth Hormone-Releasing Hormone / Q000097:blood / Q000378:metabolism; D008297:Male; D013004:Somatostatin / Q000097:blood / Q000378:metabolism; D014280:Triglycerides / Q000494:pharmacology*
D014280:Triglycerides; D013004:Somatostatin; D013006:Growth Hormone; D013007:Growth Hormone-Releasing Hormone