Current knowledge of d-aspartate in glandular tissues
- 373 Downloads
Free d-aspartate (d-Asp) occurs in substantial amounts in glandular tissues. This paper reviews the existing work on d-Asp in vertebrate exocrine and endocrine glands, with emphasis on functional roles. Endogenous d-Asp was detected in salivary glands. High d-Asp levels in the parotid gland during development suggest an involvement of the amino acid in the regulation of early developmental phases and/or differentiation processes. d-Asp has a prominent role in the Harderian gland, where it elicits exocrine secretion through activation of the ERK1/2 pathway. Interestingly, the increase in NOS activity associated with d-Asp administration in the Harderian gland suggests a potential capability of d-Asp to induce vasodilatation. In mammals, an increase in local concentrations of d-Asp facilitates the secretion of anterior pituitary hormones, i.e., PRL, LH and GH, whereas it inhibits the secretion of POMC/α-MSH from the intermediate pituitary and of oxytocin from the posterior pituitary. d-Asp also acts as a negative regulator for melatonin synthesis in the pineal gland. Further, d-Asp can stereo-specifically modulate the production of sex steroids, thus taking part in the endocrine control of reproductive activity. Although d-Asp receptors remain to be characterized, gene expression of NR1 and NR2 subunits of NMDAr responds to d-Asp in the testis.
Keywordsd-Aspartate Salivary glands Harderian gland Endocrine glands d-Aspartate oxidase Aspartate racemase
Conflict of interest
The authors declare no conflict of interest.
- D’Aniello A, Di Fiore MM, Fisher GH, Milone A, Seleni A, D’Aniello S, Perna AF, Ingrosso D (2000a) Occurrence of d-aspartic acid and N-methyl-d-aspartic acid in rat neuroendocrine tissues and their role in the modulation of luteinizing hormone and growth hormone release. FASEB J 14:699–714PubMedGoogle Scholar
- D’Aniello G, Ronsini S, Notari T, Grieco N, Infante V, D’Angelo N, Mascia F, Di Fiore MM, Fisher G, D’Aniello A (2012) d-Aspartate, a key element for the improvement of sperm quality. Adv Sex Med 2:47–53Google Scholar
- Osamura S (2000) Studies on peroxisomal d-asparate oxidase in rat salivary glands. J Kyushu Dent Soc 54:86–94Google Scholar