Distal Retinal Pigment Research Articles

Red pigment-concentrating hormone induces a calcium-mediated retraction of distal retinal pigments in the crayfish.

The octapeptide red pigment-concentrating hormone is capable of eliciting the aggregation of intracellular pigment granules in distal retinal pigment cells of isolated retinas of the crayfish Procambarus clarkii (Girard). The final level and the time course of pigment aggregation are dose dependent within a range of 10(-10) mol l(-1) to 10(-4) mol l(-1). The effect of red pigment-concentrating hormone is prevented by previous incubation with an anti- red pigment-concentrating hormone antibody; however, application of the antibody after the onset of the red pigment-concentrating hormone effect, does not prevent its full development. A similar effect to that elicited by red pigment-concentrating hormone is induced by the calcium ionophores ionomycin and A-23187. Red pigment-concentrating hormone evokes entry of 45Ca2+ to retinal cells. However, the red pigment-concentrating hormone-induced pigment aggregation persists in the presence of the calcium channel blocker verapamil and in Ca2+-free solutions. Caffeine and thapsigargin, known to release calcium from intracellular stores, elicit distal pigment aggregation, while ryanodine and dantrolene, blockers of intracellular calcium release, as well as the intracellular calcium chelator bapta-AM suppress the effect of red pigment-concentrating hormone. These results suggest that red pigment-concentrating hormone elicits distal retinal pigment aggregation by increasing intracellular calcium concentration, acting via a dual mechanism: (1) promoting calcium entry, and (2) releasing intracellular calcium.

Modulation of crayfish retinal function by red pigment concentrating hormone

The role of the crustacean octapeptide red pigment concentrating hormone (RPCH) in the control of crayfish retinal activity was explored. RPCH injection into intact animals resulted, after a latency of 10­30 min, in a dose-dependent enhancement of electroretinogram (ERG) amplitude lasting 60­120 min. RPCH was able to potentiate ERG amplitude in both light-adapted and dark-adapted animals. Following light-adaptation, responsiveness to RPCH was five times higher than following dark-adaptation. In conjunction with ERG enhancement, in light-adapted animals, RPCH injection elicited a dose-dependent retraction of distal retinal pigment, but did not affect proximal retinal pigment position. The effects of RPCH were blocked by a polyclonal antibody raised against a tyrosinated form of RPCH (A-tyr-RPCH). The antibody was also capable of partially blocking the nocturnal phase of the circadian rhythm of ERG amplitude and the darkness-induced retraction of distal retinal pigment. These results suggest that RPCH acts both on the retinal photoreceptors and on the distal pigment cells, playing a physiological role as a mediator of the effects induced by darkness and by the nocturnal phase of the circadian rhythm.

Release of black pigment-dispersing hormone and distal retinal pigment light-adapting hormone upon electrical stimulation of the isolated eyestalk neuroendocrine complex of the fiddler crab, Uca pugilator

1. Pretreatment of isolated eyestalk tissues of the fiddler crab, Uca pugilator, with drugs that interfere with norepinephrinergic neurotransmission, alpha-methyl- p-tyrosine, fusaric acid, 6-hydroxy-dopamine, and bretylium, prior to electrical stimulation resulted in the release of significantly less black pigment-dispersing hormone (BPDH) and light-adapting hormone (LAH) than from tissues that had been kept in saline alone prior to being electrically stimulated. 2. These data support the hypothesis that norepinephrine has a physiological role in stimulating release of BPDH and LAH in the fiddler crab.

Distal retinal pigment of the fiddler crab, Uca pugilator: release of the dark-adapting hormone by methionine enkephalin and FMRFamide.

The neuropeptides methionine enkephalin and FMRFamide, when injected into intact fiddler crabs, Uca pugilator, produce dark adaptation of the distal retinal pigment. Furthermore, both neuropeptides stimulate release of distal retinal pigment dark-adapting hormone activity from the isolated eyestalk neuroendocrine complex. It is hypothesized that both neuropeptides, when injected into intact fiddler crabs, act only indirectly on the distal retinal pigment, by stimulating release of this dark-adapting hormone.

Distal retinal pigment of the fiddler crab, Uca pugilator: Evidence for stimulation of release of light adapting and dark adapting hormones by neurotransmitters

1. 1. In intact fiddler crabs, Uca pugilator, norepinephrine (NE) produced light adaptation of the distal retinal pigment whereas dopamine (DA) produced dark adaptation of this pigment. 2. 2. Presumably, NE stimulated release of distal retinal pigment light adapting hormone whereas DA released distal retinal pigment dark adapting hormone. 3. 3. NE appeared to produce its effect by activation of alpha 1 postsynaptic adrenoceptors. 4. 4. Pandalus red pigment concentrating hormone produced dark adaptation of the distal retinal pigment.

C-terminal deletion analogs of a crustacean pigment-dispersing hormone

This study deals with the effect of deamidation and C-terminal truncation on the potency of an octadecapeptide pigment-dispersing hormone (PDH: Asn- Ser-Gly-Met-Ile-Asn-Ser-Ile-Leu-Gly-Ile-Pro-Arg-Val-Met-Thr-Glu-Ala-NH 2), first described as light-adapting distal retinal pigment hormone (DRPH) from Pandalus borealis. Bioassay of synthetic analogs for melanophore pigment dispersion in destalked fiddler crabs ( Uca pugilator) showed that deamidation causes a 300-fold decrease in potency. The analogs 1–17-NH 2 and 1–16-NH 2 were about 3 times more potent than 1–18-OH. Further truncation led to decreases in potency, with the peptide 1–9-NH 2 being the smallest C-terminal deletion analog to display activity (0.001% potency). Smaller analogs (1–8-NH 2, 1–6-NH 2 and 1–4-NH 2) were inactive when tested in doses as high as 500 nmoles/crab. On the basis of our earlier work on N-terminal deletion analogs and the present findings the residues 6 to 9 seem to be important for PDH action.

Substitution of norleucine for methionine residues in a crustacean pigment-dispersing hormone

In order to evaluate the structural/functional roles of Met residues in an octadecapeptide pigment-dispersing hormone (PDH: Asn-Ser-Gly-Met-Ile-Asn-Ser-Ile-Leu-Gly-Ile-Pro-Arg-Val-Met-Thr-Glu-Ala-NH 2), first described as light-adapting distal retinal pigment hormone (DRPH) from Pandalus, three analogs were synthesized: Nle 4-PDH, Nle 15-PDH, and Nle 4,15-PDH. When tested for melanophore pigment-dispersing activity in destalked Uca, all three Nle-analogs were more potent than unsubstituted PDH. Performic acid oxidation caused a marked loss of potency of PDH, Nle 4-PDH, and Nle 15-PDH. The analog Nle 4,15-PDH was resistant to oxidation and displayed 6-fold higher potency than PDH. Thus Met 4 and Met 15 are not essential for the PDH activity. The oxidation-induced loss of activity of unsubstituted PDH may result from introduction of oxygen (in methionine sulfone) and a consequent conformational change in the octadecapeptide.

Chemical Properties and Physiological Actions of Crustacean Chromatophorotropins

The crustacean pigment-translocating hormones, the red pigment-concentrating hormone (RPCH), an octapeptide, and the light-adapting distal retinal pigment hormone (DRPH), an octadecapeptide, are the first invertebrate neurohormones to be fully characterized. Studies with both purified and synthetic hormones show that, in certain decapods, RPCH is a general pigment-concentrating hormone (PCH), affecting the pigments of all kinds of chromatophores (erythrophores, xanthophores, leucophores and melanophores); the DRPH seems to serve not only light-adapting function, but also act as a general chromatophore pigment-dispersing hormone (PDH). The two hormones thus function as antagonists when regulating the color-adaptation of the decapod crustaceans. PCH activity is widely distributed within the arthropod endocrine systems. The first characterized insect neurohormones, the locust adipokinetic hormones (AKH I and AKH II), show close structural similarities to the crustacean hormone, indicating a common evolution of some of the arthropod neurohormones. Physiological studies of the three hormones (RPCH, AKH I, and AKH II) and their synthetic analogs show that they crossreact, i.e., they all exhibit pigment-concentrating activity when tested on decapod crustaceans, adipokinetic activity when tested on locusts, and hyperglycemic activity when tested on cockroaches, although each of the hormones is more potent in its own system. Structure-function studies show, however, that quite different binding-site requirements exist for the hormones in activating their receptors on the various target tissues. The physiological specificity in their action therefore seems to depend on a differential evolution of the hormone receptors.

Invertebrate neuropeptide hormones.

The development of a long-term research program on the neurosecretory hormones of arthropods is described. The purification and full characterization of the first invertebrate neurohormones, the red pigment-concentrating hormone (RPCH) and the distal retinal pigment hormone (DRPH) demonstrated that they are peptides, an octapeptide and an octadecapeptide, respectively. Physiological function studies with the pure hormones and their synthetic preparations showed that the RPCH acts as a general pigment-concentrating hormone (PCH), and that the DRPH, in addition to its light-adaptive function, also constitutes a general pigment-dispersing hormone (PDH). In the regulation of the color-adaptation of the animals, the two hormones act as antagonists. The chromatophorotropic activities are widely distributed within the arthropod neuroendocrine systems. Purification of the pigment-concentrating activities from the locust corpora cardiaca lead to the isolation and characterization of the first insect neurohormones, the adipokinetic hormones (AKH I and AKH II). These two hormones, AKH I being a decapeptide and AKH II being an octapeptide, are close structural analogs to the crustacean PCH, demonstrating a common evolution of arthropod neurohormones. The hormones of this PCH-family all cross-react, but structure-function studies of the hormones show that quite different parts of their structure are involved in their binding to the various receptors.

Structure of a light-adapting hormone from the shrimp, Pandalus borealis

The structure of a light-adapting hormone of the shrimp, Pandalus borealis, has been determined. The hormone, which had been isolated from Pandalus eyestalks and which adapts the shrimp to brighter light conditions by causing the pigment in the distal retinal pigment cells of the eye to move into a more proximal position, is the peptide: Asn-Ser-Gly-Met-Ile-Asn-Ser-Ile-Leu-Gly-Ile-Pro-Arg-Val-Met-Thr-Glu-Ala-NH 2. The structure was obtained by sequence analysis by the dansyl-Edman method of the intact hormone and of isolated tryptic and thermolytic peptides.

Crustacean Neurosecretory Hormones and Physiological Specificity

Physiological effects of neurosecretory factors from crustaceans are examined for their hormonal specificity. Hyperglycemic hormone (HGH) from the eyestalk is a polypeptide, molecular weight about 7,000; it may activate phosphorylase and inhibit glycogen synthetase. Four pigmentary effectors (distal retinal pigment, melanophores, erythrophores and leucophores) respond to a peptide hormone (DRPH) having a molecular weight of 2,000. An earlier suggestion (Kleinholz, 1970) that light-adaptation of the distal retinal pigment and dispersion of pigment granules in chromatophores may be regulated by the same hormonal molecule is confirmed by test with synthetic hormone. Concentrators oferythrophore (ECH) and leucophore (LCH) pigments are peptides with respective molecular weights of 1,000 and about 1,500 daltons. Three factors which affect succinate oxidation by mitochondria appear in the three chromatographic zones eluted from G-25 Sephadex which contain DRPH, LCH and ECH, and therefore presumably are of about the same molecular size as the pigment hormones. The second and third of these factors have been shown to be distinctly different from the hormones with which they are initially eluted. Factors influencing hydromineral regulation, molt- and gonad-inhibition, cardiac activity, respiratory rates and lipid metabolism are reviewed.

Color changes induced by certain indole alkaloids in the fiddler crab, UCA

1. 1. Lysergic acid diethylamide (LSD) evokes distal retinal pigment light adaptation and erythrophoric pigment concentration. 2. 2. The erythrophoric responses to LSD are not dependent on the amount of light striking the rhabdoms in the eyes. 3. 3. Isolysergic acid amide and psilocin evoke erythrophoric pigment concentration in intact fiddler crabs but not in eyestalkless crabs nor in vitro in isolated legs. It was already known that LSD evokes such pigment concentration in intact crabs only. 4. 4. Of the three alkaloids used, LSD was the most potent while psilocin was the least potent in evoking the observed effects on the erythrophores. 5. 5. These indole alkaloids do not stimulate the erythrophores directly. Their actions appear to be mediated by the neuroendocrine system.

The eye and some effects of light on locomotor activity in Nephrops norvegicus

The compound eye of Nephrops norvegicus (L.) is of the “superposition” type, well-adapted to the low levels of light prevailing at the sea bed during the activity periods of the species. Only the proximal retinal shielding pigment responds to light, the distal retinal shielding pigment being in the dark-adapted position at all times. The response of the proximal pigment appears to vary seasonally. Field observations compared light intensity at the sea bed with the numbers of N. norvegicus caught by trawl at various times of day in the Irish Sea in summer and winter. Laboratory experiments were combined with these field data to indicate that light is an important modulator of locomotor activity in this species.

COMPARISON OF THE PIGMENTARY EFFECTOR TROPINS IN THE EYESTALKS AND ABDOMINAL NERVE CORD OF THE PRAWNPALAEMONETES VULGARIS

1. Extracts of the eyestalks and abdominal nerve cords of the prawn Palaemonetes vulgaris were chromatographed on Bio-Gel P-6. The fractions of both extracts revealed melanin-dispersing activity in the fiddler crab Uca pugilator and red and white pigment-dispersing activities and distal retinal pigment light-adapting activity in the prawn. In addition, the eyestalk fractions contained red and white pigment-concentrating activities whereas only the red pigment-concentrating activity was found in the fractions of the abdominal nerve cords.2. The pigment-dispersing and distal retinal pigment light-adapting activities were eluted from the column ahead of the pigment-concentrating activities and were consequently separated from them. However, the pigment-dispersing and distal retinal pigment light-adapting activities did not separate from each other. The pigment-concentrating activities likewise did not separate from each other.3. The substance from the prawn which evokes melanin dispersion in the fiddler crab is not the substance that causes red pigment dispersion and perhaps white pigment dispersion as well in the prawn itself.4. Furthermore, dispersion of the red and white chromatophoric pigments in the prawn is not caused by the substance that evokes light adaptation of its distal retinal pigment.5. Evidence is presented to support the hypothesis that light-adaptation of the distal retinal pigment in Palaemonetes is caused by the substance found in the prawn that causes melanin dispersion in the fiddler crab. Palaemonetes itself lacks melanophores.

Separation, Assay, and Properties of the Distal Retinal Pigment Light-Adapting and Dark-Adapting Hormones in the Eyestalks of the Prawn Palaemonetes vulgaris

Next article No AccessSeparation, Assay, and Properties of the Distal Retinal Pigment Light-Adapting and Dark-Adapting Hormones in the Eyestalks of the Prawn Palaemonetes vulgarisMilton Fingerman, Robert A. Krasnow, and Sue W. FingermanMilton Fingerman Search for more articles by this author , Robert A. Krasnow Search for more articles by this author , and Sue W. Fingerman Search for more articles by this author PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by Volume 44, Number 3Jul., 1971 Article DOIhttps://doi.org/10.1086/physzool.44.3.30155564 Views: 2Total views on this site Citations: 15Citations are reported from Crossref Journal History This article was published in Physiological Zoology (1928-1998), which is continued by Physiological and Biochemical Zoology (1999-present). PDF download Crossref reports the following articles citing this article:Bernard R. Landau, Joseph Katz Pathways of glucose metabolism, (Jan 2011).https://doi.org/10.1002/cphy.cp050125Matthew Landau, William J. Biggers, Hans Laufer Invertebrate Endocrinology, (Jan 2011): 1291–1390.https://doi.org/10.1002/cphy.cp130218K. Ranga Rao, John P. Riehm Pigment-dispersing hormones: A novel family of neuropeptides from arthropods, Peptides 9 (Jan 1988): 153–159.https://doi.org/10.1016/0196-9781(88)90239-2GUNDERAO K. KULKARNI, MILTON FINGERMAN Distal Retinal Pigment of the Fiddler Crab, Uca pugilator: Release of the Dark-Adapting Hormone by Methionine Enkephalin and FMRFamide, Pigment Cell Research 1, no.11 (Jul 1987): 51–56.https://doi.org/10.1111/j.1600-0749.1987.tb00534.xGunderao K. Kulkarni, Milton Fingerman Distal retinal pigment of the fiddler crab, Uca pugilator: Evidence for stimulation of release of light adapting and dark adapting hormones by neurotransmitters, Comparative Biochemistry and Physiology Part C: Comparative Pharmacology 84, no.22 (Jan 1986): 219–224.https://doi.org/10.1016/0742-8413(86)90086-1K. RANGA RAO Pigmentary Effectors, (Jan 1985): 395–462.https://doi.org/10.1016/B978-0-12-106409-9.50017-8L.H. KLEINHOLZ Biochemistry of Crustacean Hormones, (Jan 1985): 463–522.https://doi.org/10.1016/B978-0-12-106409-9.50018-XBeatriz Fuentes-Pardo, M.C García Effect of the light-deprivation on the neurohumoral activity of the visual system of the crayfish, Comparative Biochemistry and Physiology Part A: Physiology 64, no.44 (Jan 1979): 549–555.https://doi.org/10.1016/0300-9629(79)90582-6Baltazar Barrera-Mera Neural coupling between left and right electroretinographic circadian oscillations in the crayfish p. bouvieri, Comparative Biochemistry and Physiology Part A: Physiology 61, no.33 (Jan 1978): 427–432.https://doi.org/10.1016/0300-9629(78)90060-9Hugo Aréchiga, Alberto Huberman, Adolfo Martínez-Palomo Release of a neurodepressing hormone from the crustacean sinus gland, Brain Research 128, no.11 (Jun 1977): 93–108.https://doi.org/10.1016/0006-8993(77)90238-4Nora Frontali, Harold Gainer Peptides in Invertebrate Nervous Systems, (Jan 1977): 259–294.https://doi.org/10.1007/978-1-4613-4130-7_10Hugo Aréchiga, Flavio Mena Circadian variations of hormonal content in the nervous system of the crayfish, Comparative Biochemistry and Physiology Part A: Physiology 52, no.44 (Jan 1975): 581–584.https://doi.org/10.1016/S0300-9629(75)80003-XMilton Fingerman Endocrine mechanisms in marine invertebrates, Life Sciences 14, no.66 (Mar 1974): 1007–1018.https://doi.org/10.1016/0024-3205(74)90227-6Milton Fingerman Comparative Endocrinology, (Jan 1974): 165–223.https://doi.org/10.1016/B978-0-12-472450-1.50010-5Milton Fingerman, Sue W. Fingerman Evidence for a substance in the eyestalks of brachyurans that darkens the shrimpCrangon septemspinosa, Comparative Biochemistry and Physiology Part A: Physiology 43, no.11 (Sep 1972): 37–46.https://doi.org/10.1016/0300-9629(72)90466-5

Control of distal retinal pigment migration in the fiddler crab Uca pugilator

Several concentrations of extracts prepared from the eyestalks of a specimen of Uca pugilator were injected into other U. pugilator individuals. The distal pigment of the eyes first became light adapted and then dark adapted, the whole process lasting 6 h. The mean integrated response for light adaptation increased progressively up to the highest tested extract (3 eyestalk equivalents/dose), but with the darkadapting response the maximal effect was produced by the extract containing 2 eyestalk equivalents/dose. Gel filtration of eyestalk extracts in Sephadex G-50 showed that the fractions associated with greatest light adaptation were also associated with greatest pigment dispersion in the melanophores. Almost no light or dark adaptation of the retinal pigment resulted from injections of eyestalk extracts treated with α-chymotrypsin which supports the interpretation that these substances are polypeptides of neurosecretory origin.

Circadian rhythm of distal retinal pigment migration in the fiddler crab,Uca Pugilator, maintained in constant darkness and its endocrine control∗∗

Abstract The distal retinal pigment in the fiddler crab, Uca pugilator, displays a circadian rhythm in constant darkness. The pigment approaches the fully light adapted position by day and the fully dark adapted position by night. This rhythm is presumably due at least to rhythmical release by day of a distal retinal pigment light‐adapting hormone. Extracts of eyestalks from Uca produce a light‐adaptational response in the crab, but extracts of eyestalks from the prawn, Palaemonetes vulgaris, do not produce a light‐adaptational response in the crab, but a dark‐adaptational response instead. In contrast, both types of extract produce a light‐adaptational response of the distal retinal pigment in Palaemonetes. The possibility of a species specificity in the action of distal retinal pigment light‐adapting hormones in crustaceans is discussed.

A progress report on the separation and purification of crustacean neurosecretory pigmentary-effector hormones

An earlier report described separation of crustacean eyestalk extract by gel filtration on G-25 Sephadex into two groups of pigmentary-effector hormones. One contains distal retinal pigment light-adapting hormone (DRPH) and melanophore dispersing hormone (MDH) in Peak 1B and the other an erythrophore concentrating hormone (ECH) in Peak 4. This is a report of progress in further purification of such hormones. Peak 1B material also disperses the pigment in leucophores and erythrophores. Further chromatography of Peak 1B material on two ion-exchangers shows the separation of several different molecular versions of a particular pigmentary-effector hormone. In addition, each active peak is effective on all four pigmentary effectors, causing light-adaptation of distal retinal pigment and dispersing the pigments in melanophores, leucophores, and erythrophores. Homogeneity of these preparations has not yet been thoroughly examined, so that it is not yet possible to state whether each active peak contains one or several pigmentary effector hormones.

Chromactivating hormones of Pandalus borealis isolation and purification of the ‘red-pigment-concentrating hormone’

1. 1. ‘Red-pigment-concentrating hormone’ and distal retinal pigment hormone from aqueous extract of lyophilized eyestalks of Pandalus borealis have been separated on Sephadex G-25. 2. 2. Low activity yields (30%) of the distal retinal pigment hormone were increased by combining the active material with separated inactive material. 3. 3. Final purification of the ‘red-pigment-concentrating hormone’ has been achieved by repeated chromatography on Sephadex LH-20 using different mixtures of water and butanol as solvent. 4. 4. The purified ‘red-pigment-concentrating hormone’ has a specific activity of 1.7·10 6 times that of dry eyestalks. The total recovery of hormone activity was about 35%. 5. 5. A reference standard for the ‘red-pigment-concentrating hormone’ is described and a unit of ‘red-pigment-concentrating hormone’ is defined. 6. 6. The hormone is a peptide containing the eight amino acids, aspartic acid, glutamic acid, glycine, leucine, phenylalanine, proline, serine and tryptophan. 7. 7. No N-terminal amino group has been found. 8. 8. Large and small erythrophores in Palaemon adspersus are both affected by this hormone.

Separation and purification of distal retinal pigment hormone and red pigment concentrating hormone of the crustacean eyestalk

Separation and purification of distal retinal pigment hormone and red pigment concentrating hormone of the crustacean eyestalk