Control of plasma levels of growth hormone, glucagon and insulin in ducklings: roles of free fatty acids and somatostatin.
The effects of plasma free fatty acids (FFA) and somatostatin-14 (S-14) on concentrations of plasma GH, glucagon and insulin were investigated in juvenile ducks. Oleic acid, S-14 or both were infused into 4- to 7-week-old birds and plasma GH, glucagon-like immunoreactivity (GLI), immunoreactive insulin (IRI) and FFA were measured. An increase in plasma GH and a decrease in GLI but no change in IRI was observed after infusion of 9 mg oleic acid/kg per min. A decrease in plasma GH, FFA and IRI and an increase in plasma GLI was seen after infusion of 800 ng S-14/kg per min. These effects of S-14 on IRI and GLI were abolished when S-14 was infused simultaneously with oleic acid. It is concluded that FFA have a direct stimulatory effect on GH secretion and an inhibitory effect on glucagon secretion. Somatostatin-14 directly inhibits the secretion of GH and its stimulatory effect on the secretion of glucagon is mediated by a depression in concentrations of plasma FFA. Finally, S-14 has no effect on plasma insulin when basal levels of plasma FFA are maintained.
Foltzer
C
C
Strosser
M T
MT
Harvey
S
S
Mialhe
P
P
D000818:Animals; D004372:Ducks; D005230:Fatty Acids, Nonesterified / Q000494:pharmacology*; D005934:Glucagon / Q000097:blood*; D013006:Growth Hormone / Q000097:blood*; D007328:Insulin / Q000097:blood*; D019301:Oleic Acid; D009829:Oleic Acids / Q000097:blood / Q000494:pharmacology; D010902:Pituitary Gland / Q000187:drug effects; D013004:Somatostatin / Q000097:blood / Q000494:pharmacology
D005230:Fatty Acids, Nonesterified; D007328:Insulin; D009829:Oleic Acids; D019301:Oleic Acid; D013004:Somatostatin; D013006:Growth Hormone; D005934:Glucagon