Occurrence and neuroendocrine role of <scp>D</scp>‐aspartic acid and <i>N</i>‐methyl‐<scp>D</scp>‐aspartic acid in <i>Ciona intestinalis</i>

D’Aniello, Antimo; Spinelli, Patrizia; Simone, Antonietta; D’Aniello, Salvatore; Branno, Margherita; Aniello, Francesco; Fisher, G. H.; Fiore, Maria Maddalena Di; Rastogi, Rakesh K.

doi:10.1016/s0014-5793(03)00921-9

Cited by 46 publications

(44 citation statements)

References 44 publications

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“…Conversely, the source of D-aspartate may come from endogenous synthesis by an unidentified aspartate racemase, because Ddo Ϫ/Ϫ testes show increased D-aspartate concomitant to decreased L-aspartate. Conversion of L-aspartate to D-aspartate has been reported in rat cerebral cortical cultures (Wolosker et al, 2000) and invertebrates (D'Aniello et al, 2003).…”

Section: Discussionmentioning

confidence: 97%

d-Aspartate Regulates Melanocortin Formation and Function: Behavioral Alterations in d-Aspartate Oxidase-Deficient Mice

et al. 2006

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Section: Discussionmentioning

confidence: 97%

d-Aspartate Regulates Melanocortin Formation and Function: Behavioral Alterations in d-Aspartate Oxidase-Deficient Mice

et al. 2006

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“…The high level of -Asp detected in the testis of the lizard during the sexual cycle implies the presence of an aspartate racemase activity, which requires conversion of -Asp to -Asp . On the other hand, in the cerebrospinal ganglion of the protocordate Ciona intestinalis, -Asp has been synthesized from -Asp by an aspartate racemase (D'Aniello et al 2003). However, indirect evidence of -Asp biosynthesis in mammalian cells was first demonstrated by Long and co-workers (1998).…”

Section: Discussionmentioning

confidence: 99%

Endocrine roles of d-aspartic acid in the testis of lizard Podarcis s. sicula

Raucci¹,

D’Aniello²,

Fiore³

2005

Journal of Endocrinology

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In the lizard Podarcis s. sicula, a substantial amount of -aspartate (-Asp) is endogenous to the testis and shows cyclic changes of activity connected with sex hormone profiles during the annual reproductive phases. Testicular -Asp content shows a direct correlation with testosterone titres and a reverse correlation with 17 -estradiol titres.In vivo experiments, consisting of i.p. injections of 2·0 µmol/g body weight of -Asp or other amino acids, in lizards collected during the three main phases of the reproductive cycle (pre-reproductive, reproductive and post-reproductive period), revealed that the testis can specifically take up and accumulate -Asp alone. Moreover, this amino acid influences the synthesis of testosterone and 17 -estradiol in all phases of the cycle. This phenomenon is particularly evident during the pre-and post-reproductive period, when endogenous testosterone levels observed in both testis and plasma were the lowest and 17 -estradiol concentrations were the highest. -Asp rapidly induces a fall in 17 -estradiol and a rise in testosterone at 3 h post-injection in the testis and at 6 h post-injection in the blood. In vitro experiments show that testicular tissue converted -Asp into -Asp through an aspartate racemase. -Asp synthesis was measured in all phases of the cycle, but was significantly higher during the reproductive period with a peak at pH 6·0. The exogenous -Asp also induces a significant increase in the mitotic activity of the testis at 3 h (P<0·05) and at 6 h (P<0·01). Induction of spermatogenesis by -Asp is recognized by an intense immunoreactivity of the germinal epithelium (spermatogonia and spermatids) for proliferation cell nuclear antigen (PCNA). The effects of -Asp on the testis appear to be specific since they were not seen in lizards injected with other -or -forms of amino acids with known excitatory effects on neurosecretion. Our results suggest a regulatory role for -Asp in the steroidogenesis and spermatogenesis of the testis of the lizard Podarcis s. sicula.

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“…Interestingly, NMDA receptors in mammals are important for reproductive control through their effects on the release of the gonadotropinreleasing hormone required for the initiation of puberty, the maintenance of reproductive capability and reproductive behaviour (Mahesh and Brann, 2005). Similar effects have been described in other vertebrates (Flynn et al, 2002), and also in a protochordate species, Ciona intestinalis, suggesting a highly conserved reproductive function in chordates (D'Aniello et al, 2003;Di Fiore et al, 2000).…”

Section: Introductionmentioning

confidence: 74%

Effects of the NMDA receptor antagonist MK-801 on female reproduction and juvenile hormone biosynthesis in the cricketGryllus bimaculatusand the butterflyBicyclus anynana

Geister

Lorenz

Hoffmann

et al. 2008

Journal of Experimental Biology

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SUMMARYApart from regulating insect development, juvenile hormones (JHs) play an important role in insect reproduction, where they initiate vitellogenin synthesis and regulate the uptake of yolk by the ovary. JH synthesis is a tightly regulated process controlled by neurons and peptidergic neurosecretory cells. One of the known stimulatory regulators of JH biosynthesis is glutamate, and its N-methyl-D-aspartate (NMDA) receptor has been recently found in the cockroach Diploptera punctata. In this study we demonstrate a strong reduction in reproductive output in the tropical butterfly Bicyclus anynana and the Mediterranean field cricket Gryllus bimaculatus caused by the NMDA receptor antagonist MK-801. Such inhibiting effects on reproduction could be overruled by the application of JH mimics. In G. bimaculatus, MK-801 inhibits in vitro JH biosynthesis in the corpora allata and reduces in vivo JH haemolymph titres in a dose-dependent manner. These results suggest that JH biosynthesis in the corpora allata is at least in part controlled by an NMDA receptor with Ca 2+ as a second level messenger. Based on our findings we consider NMDA receptor antagonists as important tools for manipulating juvenile hormone biosynthesis and therefore for gaining a better understanding of the mechanistic basis of reproduction.

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Occurrence and neuroendocrine role of D‐aspartic acid and N‐methyl‐D‐aspartic acid in Ciona intestinalis

Cited by 46 publications

References 44 publications

d-Aspartate Regulates Melanocortin Formation and Function: Behavioral Alterations in d-Aspartate Oxidase-Deficient Mice

d-Aspartate Regulates Melanocortin Formation and Function: Behavioral Alterations in d-Aspartate Oxidase-Deficient Mice

Endocrine roles of d-aspartic acid in the testis of lizard Podarcis s. sicula

Effects of the NMDA receptor antagonist MK-801 on female reproduction and juvenile hormone biosynthesis in the cricketGryllus bimaculatusand the butterflyBicyclus anynana

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