Molecular cloning of growth hormone secretagogue-receptor and effect of quail ghrelin on gastrointestinal motility in Japanese quail

The chicken is an interesting animal for study of the functional role of ghrelin in the gastrointestinal tract

“…In contrast, ghrelin caused contraction of unstimulated GI strips and potentiation of EFS-induced contraction in chickens [15]. The responsiveness of ghrelin was GI region-dependent, and expression of receptor mRNA is correlated with ghrelin-induced contraction [13][14][15]. However, the excitatory response is not general in avian species because ghrelin had no effect on GI motility in the Japanese quail despite the expression GHS-R1a mRNA [14].…”

“…The responsiveness of ghrelin was GI region-dependent, and expression of receptor mRNA is correlated with ghrelin-induced contraction [13][14][15]. However, the excitatory response is not general in avian species because ghrelin had no effect on GI motility in the Japanese quail despite the expression GHS-R1a mRNA [14]. In rodents, ghrelin caused contraction of electrically stimulated GI strips but did not cause contraction of unstimulated strips, probably due to the lack of myogenic GHS-R1a [4,5].…”

“…After anesthesia (fish and birds) or immobilization by spinal destruction (bullfrog and fire belly newt), the stomach and intestine were isolated. The isolated GI strips (3×10 mm) were suspended vertically in an organ bath containing physiological salt solutions [10][11][12][13][14]. Ghrelin and muscle stimulants were applied to the bath, and the induced mechanical changes were analyzed.…”

“…The primer sets and protocol used in the following species (goldfish, bullfrog, Japanese fire belly newt, chicken and Japanese quail) have been published in respective papers [10][11][12][13][14].…”

Effects of peripheral ghrelin on growth performance, selected blood biochemical parameters and thyroid hormone in Japanese quail (Coturnix coturnix japonica)

“…Yoshimura et al (25) found that ghrelin-producing cells exist in the reproductive organs of Japanese quail, especially in the mucosal epithelium of the oviduct, and ghrelin-producing/releasing activity is associated with the development of this organ. In a comparative study, Kitazawa et al (11) reported that ghrelin has contractile effects on upper and lower segments of gastrointestinal tract and it stimulates motility of middle intestine in quail. Shousha et al (21) who had reported initial results on peripheral and central effects of rat ghrelin showed that different methods and dosages of ghrelin administration might have different effects on feed intake in Japanese quail, and low dosages of peripheral ghrelin may act as hunger signal in birds.…”