Table 1.
Summary of positive regulators of pituitary GH: Neurotransmitters.
| Neurotransmitters | Groups | Roles | References |
|---|---|---|---|
| Dopamine | Fish | ↑ GH mRNA (PKA–dependent) in tilapia | (105) |
| ↑ GH secretion both directly and somatostatin–dependent in goldfish | (106, 107) | ||
| ↑ GH secretion in common carp | (108) | ||
| Amphibian, reptiles and birds | Little ↑ or no effect on GH | (109, 110) | |
| Mammals | ↑ GH secretion in an isolated case of human acromegaly, but generally ↓ GH | (111), Table 4 | |
| Serotonin | Mammals | ↑ GH secretion (somatostatin/GHRH–dependent) | (28, 38) |
| Fish and birds | Opposite results also observed | Table 4 | |
| Acetylcholine | Mammals | ↑ GH secretion | (112, 113–116) |
| Birds | Opposite results observed in chicken | Table 4 | |
| Amino acids and derivatives | Fish | Glutamate ↑ GH secretion in rainbow trout | (117) |
| Cysteamine ↑ GH secretion through somatostatin–depletion in grass carp | (118, 119) | ||
| Mammals | Argninine ↑ GH mRNA and secretion in rat | (120, 121) | |
| Cysteamine ↑ GH secretion through somatostatin–depletion in sheep | (122) |