+ Resolve Article
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter

+ Translate
+ Subscribe to Site Feed
GeoScience Most Shared ContentMost Shared Content

Inhibitory modulation of photoreceptor melatonin synthesis via a nitric oxide-mediated mechanism

, : Inhibitory modulation of photoreceptor melatonin synthesis via a nitric oxide-mediated mechanism. Neurochemistry International 45(8): 1143-1153

Nitric oxide (NO) has been suggested to have many physiological functions in the vertebrate retina, including a role in light-adaptive processes. The aim of this study was to examine the influence of the NO-donor sodium nitroprusside (SNP) on the activity of arylalkylamine-N-acetyltransferase (AA-NAT; EC., the activity of which responds to light and reflects the changes in retinal melatonin synthesis-a key feature of light-adaptive responses in photoreceptors. Incubation of dark-adapted and dark-maintained retinas with SNP lead to the NO-specific suppression of AA-NAT activity, with NO suppressing AA-NAT activity to a level similar to that seen in the presence of dopaminergic agonists or light. Increased levels of cGMP appeared to be causally involved in the suppression of AA-NAT activity by SNP, as non-hydrolysable analogues of cGMP and the cGMP-specific phosphodiesterase (PDE) inhibitor zaprinast also significantly suppressed AA-NAT activity, while an inhibitor of soluble guanylate cyclase blocked the effect of SNP. While this chain of events may not be part of the normal physiology of the retina, it could be important in pathological circumstances that are associated with marked increase in levels of cGMP, as is found to be the case in certain forms photoreceptor degeneration, which are produced by defects in cGMP phosphodiesterase activity. Copyright 2004 Elsevier Ltd. All rights reserved.


PMID: 15380624

DOI: 10.1016/j.neuint.2004.06.014

Other references

Schaller Waldemar Theodore, 1957: Memorial of William Frederick Foshag. American Mineralogist 42(3-4): 249-255

Yamane, Y.; Maejima, J.; Yazaki, S.; Fukumoto, S., 1977: Additional 11 cases of diplogonoporiasis in Sanin districts. Epidemiological surveys in Tottori and Shimane Prefectures, Japan, in 1972 and 1976 revealed 11 new cases of human infection with Diplogonoporus grandis, bringing the total in Japan to 73 cases. All the patients were male and all had eaten raw fis...

Medeiros, L.D., 1973: The Mozambique Provincial Institute of Public Health--annual report 1971. Anais do Instituto de Higiene E Medicina Tropical 1(1-4): 317-345

Boris Khesin; Shimon Feinstein; Yevgeny Vapnik; Sophia Itkis; Roman Leonhardt, 2005: Magnetic study of metamorphosed sedimentary rocks of the Hatrurim Formation, Israel. Geophysical Journal International 162(1): 49-63

Keyte, B.; Gershon, H., 1998: Developing a successful product line strategy. By looking beyond traditional organizational boundaries and integrating the clinical and administrative activities from a system perspective, providers and their partners will improve their ability to compete by providing better, more effective ca...

Krach, W., 1986: The Eocene mollusc fauna from Koniusza near Przemysl (Polish eastern Carpathians). Annales Societatis Geologorum Poloniae. 1985 ; 551-2: 139-190

British Ornithologists Union Records Committee., 1995: British Ornithologists' Union. Records Committee: twenty-second report (May 1995). Ibis. October; 1374: 590-591

Anonymous, 1974: The South Trondelag Forest Society; 75 years. Landbrukstidende 0, 80 (29) 672-673

Sarkany, S., Mrs., 1965: The active principle of chamomile (M. chamomilla L.) and a survey of the literature on breeding. This review of Hungarian and other work, with more than 100 references, includes a short section on breeding for improved content of azulene and essential oils.

Hilton, Wm, 1941: Nervous system and sense organs of Cephalopods. The nervous system of the Tetra-branchia resembles that of Chiton. The cerebral, pedal, and visceral ganglia form 3 half loops. The cerebral center supplies the eyes, octocysts, lips, etc.; the visceral the mantle, gills, and viscera; and the peda...