Nucleoside triphosphates and hydrolysis-resistant analogues: effects on PIII responses in the isolated skate retina.
Responses to test flashes were recorded extracellularly from the aspartate-treated, isolated retina of the skate, before and after topical application to the retina of solutions containing GTP, ATP, or certain hydrolysis-resistant analogues. When applied to strongly light-adapted retinas (greater than or equal to 87% bleached), the analogues p(CH2)ppG, p(NH)ppG and p(CH2)ppA induced sustained decreases in threshold of the PIII response. Similar treatment of light-adapted retinas with GTP or ATP also promoted decreases in threshold, but these changes appeared relatively transient. All of the test substances lacked significant activity when applied to dark-adapted (unbleached) retinas. The results are discussed in relation to other studies examining the effects of light on GTP- and ATP-dependent processes within the photoreceptors.
D000221:Adaptation, Ocular; D000255:Adenosine Triphosphate / Q000031:analogs & derivatives / Q000494:pharmacology*; D000818:Animals; D003623:Dark Adaptation; D005074:Evoked Potentials, Visual / Q000187:drug effects; D005399:Fishes; D006160:Guanosine Triphosphate / Q000031:analogs & derivatives / Q000494:pharmacology*; D006868:Hydrolysis; D066298:In Vitro Techniques; D012160:Retina / Q000502:physiology*; D012684:Sensory Thresholds / Q000187:drug effects
D006160:Guanosine Triphosphate; D000255:Adenosine Triphosphate