Ghrelin does not affect gastrointestinal contractility in rainbow trout and goldfish in vitro

Kitazawa, Takio; Itoh, Kentaro; Yaosaka, Noriko; Maruyama, Kouichi; Matsuda, Kouhei; Teraoka, Hiroki; Kaiya, Hiroyuki

doi:10.1016/j.ygcen.2012.06.025

Cited by 23 publications

(14 citation statements)

References 48 publications

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“…Indirect effects on food intake, through stimulatory actions on digestion, could subsequently affect onset of feeding. For instance, rat GHRL evoked intestinal contraction in zebrafish (192, 193), but homologous Ghrl did not affect GI-tract contractility in goldfish and rainbow trout (194). The presence of GH secretagogue receptor in the fish pituitary and brain (particularly hypothalamus and telencephalon) also suggests a direct action of octanoylated Ghrl in these tissues (195, 196).…”

Section: Peripheral Signalsmentioning

confidence: 97%

Appetite-Controlling Endocrine Systems in Teleosts

et al. 2017

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Mammalian studies have shaped our understanding of the endocrine control of appetite and body weight in vertebrates and provided the basic vertebrate model that involves central (brain) and peripheral signaling pathways as well as environmental cues. The hypothalamus has a crucial function in the control of food intake, but other parts of the brain are also involved. The description of a range of key neuropeptides and hormones as well as more details of their specific roles in appetite control continues to be in progress. Endocrine signals are based on hormones that can be divided into two groups: those that induce (orexigenic), and those that inhibit (anorexigenic) appetite and food consumption. Peripheral signals originate in the gastrointestinal tract, liver, adipose tissue, and other tissues and reach the hypothalamus through both endocrine and neuroendocrine actions. While many mammalian-like endocrine appetite-controlling networks and mechanisms have been described for some key model teleosts, mainly zebrafish and goldfish, very little knowledge exists on these systems in fishes as a group. Fishes represent over 30,000 species, and there is a large variability in their ecological niches and habitats as well as life history adaptations, transitions between life stages and feeding behaviors. In the context of food intake and appetite control, common adaptations to extended periods of starvation or periods of abundant food availability are of particular interest. This review summarizes the recent findings on endocrine appetite-controlling systems in fish, highlights their impact on growth and survival, and discusses the perspectives in this research field to shed light on the intriguing adaptations that exist in fish and their underlying mechanisms.

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Section: Peripheral Signalsmentioning

confidence: 97%

Appetite-Controlling Endocrine Systems in Teleosts

et al. 2017

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“…The final concentrations selected for TTX and carbachol (1 µmol l −1 ) have previously been demonstrated to diminish/abolish or induce gastrointestinal motility in fish, respectively (Jensen and Holmgren, 1985;Karila and Holmgren, 1995;Kitazawa et al, 2012). The final bath concentration selected for benzbromarone (100 µmol l −1 ) was selected after initial testing of both 10 µmol l −1 and 100 µmol l −1 , which were concentrations demonstrated to successfully block Ano1 in mammalian studies (Bernstein et al, 2014;Huang et al, 2012).…”

Section: Recording and Analysis Of Gastrointestinal Motility Patternsmentioning

confidence: 99%

The presence and role of interstitial cells of Cajal in the proximal intestine of shorthorn sculpin (Myoxocephalus scorpius)

Brijs

Hennig

Kellermann

et al. 2016

Journal of Experimental Biology

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Rhythmic contractions of the mammalian gastrointestinal tract can occur in the absence of neuronal or hormonal stimulation owing to the generation of spontaneous electrical activity by interstitial cells of Cajal (ICC) that are electrically coupled to smooth muscle cells. The myogenically driven component of gastrointestinal motility patterns in fish probably also involves ICC; however, little is known of their presence, distribution and function in any fish species. In the present study, we combined immunohistochemistry and in vivo recordings of intestinal motility to investigate the involvement of ICC in the motility of the proximal intestine in adult shorthorn sculpin (Myoxocephalus scorpius). Antibodies against anoctamin 1 (Ano1, a Ca 2+ -activated Cl − channel), revealed a dense network of multipolar, repeatedly branching cells in the myenteric region of the proximal intestine, similar in many regards to the mammalian ICC-MY network. The addition of benzbromarone, a potent blocker of Ano1, altered the motility patterns seen in vivo after neural blockade with TTX. The results indicate that ICC are integral for the generation and propagation of the majority of rhythmic contractile patterns in fish, although their frequency and amplitude can be modulated via neural activity.

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“…The enteric neuron-mediated response was also not affected by ghrelin in the case of goldfish despite detectable expression of GHS-R1a mRNA. The results suggest that ghrelin does not affect the GI motility of fish and amphibians [10,11], although we should examine the in vivo effects. It is necessary to examine the involvement of ghrelin in other physiological events in the GI tract of these species.…”

Section: Discussionmentioning

confidence: 91%

“…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.…”

Section: Contraction Studymentioning

confidence: 99%