Regulation of circulating levels of the crustacean hyperglycemic hormone: evidence for a dual feedback control system

Santos, Euclydes A; Keller, Rainer

doi:10.1007/bf00265641

Cited by 62 publications

(41 citation statements)

References 31 publications

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“…In view of the coincident patterns of hormone release and raised lactate levels, it could reasonably be proposed that raised lactate levels cause CHH release, as suggested by Santos and Keller (Santos and Keller, 1993). In exercise experiments (Fig.2), it was clear that increases in lactate and CHH were correlated, and in the experiments concerned with exercise and metabolite-feedback loops, increases in CHH were accompanied by dramatic increases in circulating lactate, as summarised in Fig.4.…”

Section: Discussionmentioning

confidence: 85%

“…This is exemplified by Basu and Kravitz (Basu and Kravitz, 2003) who have shown, using a combination of immunohistochemistry and electrophysiological techniques, that the neurotransmitters octopamine and serotonin inhibit spontaneous bursting of CHH immunoreactive neurones in the second thoracic nerve roots of Homarus americanus. In view of previous work either supporting the idea that CHH levels might be controlled via feedback mechanisms involving metabolites such as glucose (Santos and Keller, 1993;Glowik et al, 1997), or proposing the involvement of CHH in lipid metabolism following the observation that CHH injection elevates haemolymph phospholipids and triglycerides in Carcinus maenas (Santos et al, 1997), experiments were designed in which various compounds (glucose, lactate, phospholipids, amino acids) were repeatedly injected over several days to raise their concentration in the haemolymph. Subsequently, crabs were exercised and their CHHrelease response measured.…”

Section: Discussionmentioning

confidence: 99%

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The adaptive significance of crustacean hyperglycaemic hormone (CHH) in daily and seasonal migratory activities of the Christmas Island red crab Gecarcoidea natalis

Morris¹,

Postel²,

Mrinalini³

et al. 2010

Journal of Experimental Biology

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SUMMARYThe Christmas Island red crab Gecarcoidea natalis undergoes extreme changes in metabolic status, ranging from inactivity during the dry season, to a spectacular annual breeding migration at the start of the wet season. The dramatic change in metabolic physiology that this polarisation entails should be reflected in changes in endocrine physiology, particularly that of the crustacean hyperglycaemic hormone (CHH), of which we know relatively little. CHH levels were measured using a novel ultrasensitive time-resolved fluoroimmunoassay (TR-FIA), together with metabolites (glucose, lactate), in the field at several scales of temporal resolution, during migratory activities (wet season) and during the inactive fossorial phase (dry season). Release patterns of CHH were measured during extreme (forced) exercise, showing for the first time an unexpectedly rapid pulsatile release of this hormone. A seasonally dependent glucose-sensitive negative-feedback loop was identified that might be important in energy mobilisation during migration. Haemolymph lactate levels were strongly correlated with CHH levels in both field and experimental animals. During migration, CHH levels were lower than during the dry season and, during migration, daytime CHH levels (when most locomotor activity occurred) increased. However, the intense dawn activity in both dry and wet seasons was not always associated with repeatable hyperglycaemia or CHH release. The results obtained are discussed in relation to the life history and behaviour of G. natalis.

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Section: Discussionmentioning

confidence: 85%

Section: Discussionmentioning

confidence: 99%

The adaptive significance of crustacean hyperglycaemic hormone (CHH) in daily and seasonal migratory activities of the Christmas Island red crab Gecarcoidea natalis

Morris¹,

Postel²,

Mrinalini³

et al. 2010

Journal of Experimental Biology

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“…Such effect, as also reported, is quite similar to that evoked by glucose. This carbohydrate has also been demonstrated to have an inhibitory effect on CHH release both in vivo (5) and in vitro (21). Nevertheless, in spite of a similarity in neuronal depression caused by glucose and serotonin, as reported in the cited experiments (21), our present results leave no doubt that serotonin has a hyperglycemic effect, which seems to be mediated by the release of CHH.…”

Section: Controlmentioning

confidence: 99%

“…Hormones produced and released by this system are known to regulate reproduction, nutrient metabolism, chromatic adaptation and growth, among several others. One of the best known crustacean hormones, with a relatively fast response time (between 1 and 2 h for maximum response), is the crustacean hyperglycemic hormone (CHH) (3)(4)(5).…”

Section: Introductionmentioning

confidence: 99%

Effects of serotonin and fluoxetine on blood glucose regulation in two decapod species

Santos

Keller

Rodríguez

et al. 2001

Braz J Med Biol Res

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One of the best known crustacean hormones is the crustacean hyperglycemic hormone (CHH). However, the mechanisms involved in hormone release in these animals are poorly understood, and thus constitute the central objective of the present study. Different groups of crustaceans belonging to diverse taxa (Chasmagnathus granulata, a grapsid crab and Orconectes limosus, an astacid) were injected with serotonin, fluoxetine, or a mixture of both, and glycemic values (C. granulata and O. limosus) and CHH levels (O. limosus) were determined after 2 h in either submerged animals or animals exposed to atmospheric air. Both serotonin and fluoxetine caused significant hyperglycemia (P<0.05) after injection into the blood sinus of the two species, an effect enhanced after exposure to atmospheric air. In C. granulata blood glucose increased from 6.1 to 43.3 and 11.4 mg/100 ml in submerged animals and from 5.7 to 55.2 and 22.5 mg/100 ml in air-exposed animals after treatment with serotonin and fluoxetine, respectively. In O. limosus the increases were from 1.2 to 59.7 and 135.2 mg/100 ml in submerged animals and from 2.5 to 200.3 and 193.6 mg/100 ml in air-exposed animals after treatment with serotonin and fluoxetine, respectively. Serotonin and fluoxetine also caused a significant increase in the circulating levels of CHH in O. limosus, from 11.9 to 43 and 45.7 fmol/ml in submerged animals and from 13.2 to 32.6 and 45.7 fmol/ml in air-exposed animals, respectively, thus confirming their action as neuroregulators in these invertebrates.

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“…Injection of the eyestalk extract or purified CHH will remedy hypoglycemia in eyestalkless individuals by regulating phosphorylase and glycogen synthase activities on the target tissues, as well as amylase secretion of the midgut gland (Sedlmeier, 1982;Keller and Sedlmeier, 1988). CHH is released in response to internal signals, such as the circadian rhythmicity of hemolymph glucose content (Kallen et al, 1990;Santos and Keller, 1993b), or to external stimuli, such as hypoxia (Santos and Keller, 1993a;Webster, 1996), parasite infection (Stentiford et al, 2001), thermal shock (Santos et al, 1997;Kuo and Yang, 1999), and pollutants (Reddy et al, 1994(Reddy et al, , 1996Lorenzon et al, 1997Lorenzon et al, , 2000. In addition to carbohydrate metabolism, CHH was proved to be involved in lipid metabolism in Chasmagnathus granulata, Carcinus maenas, and Orconectes limosus (Santos et al, 1997).…”

Section: Introductionmentioning

confidence: 99%

Cloning of Two Crustacean Hyperglycemic Hormone Isoforms in Freshwater Giant Prawn ( Macrobrachium rosenbergii ): Evidence of Alternative Splicing

Chen

Lin

Kuo

2004

Marine Biotechnology

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A full-length chh cDNA was cloned from the eyestalk of Macrobrachium rosenbergii. The 991-bp cDNA contains an open reading frame of 408 bp that encodes the prepro-CHH. The tissue-specific expression pattern was examined by reverse transcriptase-polymerase chain reaction. Positive signals were detected in the eyestalk, heart, gills, antennal glands, and thoracic ganglion but not in muscle and hepatopancreas. However, two types of products were observed. The nucleotide sequences revealed the existence of 2 chh transcripts, named chh and chh-l, respectively. Direct sequence evidence suggests that these two isoforms come from a Chh gene transcribed in an alternative splicing manner. The Mar-Chh gene consists of 4 exons. The eyestalk transcript (chh) contains exons I, II, and IV, whereas the chh-l transcript in heart, gills, antennal glands, and thoracic ganglion contains all 4 exons. The appearance of exon III in chh-l cDNA changes the sequence content in the latter half of the mature peptide, starting within the codon of the 40 th residue, arginine. The amino acid sequence deduced from exon III matched no homologue in public protein databases, while the 2 cysteine residues in this segment preserved the positional conservation characters of CHH neuropeptide family members. The common organization of Chh genes between palaemonid, brachyuran, and astacus crustaceans suggests that the Chh gene has a 4-exon structure in these species.

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Regulation of circulating levels of the crustacean hyperglycemic hormone: evidence for a dual feedback control system

Cited by 62 publications

References 31 publications

The adaptive significance of crustacean hyperglycaemic hormone (CHH) in daily and seasonal migratory activities of the Christmas Island red crab Gecarcoidea natalis

The adaptive significance of crustacean hyperglycaemic hormone (CHH) in daily and seasonal migratory activities of the Christmas Island red crab Gecarcoidea natalis

Effects of serotonin and fluoxetine on blood glucose regulation in two decapod species

Cloning of Two Crustacean Hyperglycemic Hormone Isoforms in Freshwater Giant Prawn ( Macrobrachium rosenbergii ): Evidence of Alternative Splicing

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