To evaluate the role of cGMP in vertebrate rod photoreceptors, two extracellular effectors of
cGMP were used (calcium and buffer), and both cGMP content and electrophysiological …

The rod photoreceptors in the vertebrate retina respond with enormous sensitivity and
reliability to light. In total darkness, rods can distinctly signal the arrival of a single photon.' …

In isolated, intact frog retinae high concentrations of cyclic 3′, 5′-guanosine
monophosphate were found. These levels decline rapidly upon flash-illumination. A …

A method is described which allows measurement of cyclic AMP and cyclic GMP in
histologically defined tissue samples containing as little as 0.6 fmol of either compound. This …

Dark-adapted cone-dominant ground squirrel retina has an average concentration of
guanosine 3′, 5′-monophosphate (cyclic GMP) of 9· 0 μmol/kg dry wt. The average …

Endogenous nucleotide levels of isolated intact ROS were analyzed by high pressure liquid
chromatography. Intact bovine ROS showed a total nucleotide concentration of 1.0 mM, ATP …

Cyclic nucleotides serve as intracellular second messengers for hormone or
neurotransmitter signals in most cell types across a wide phylogenetic spectrum. In the …

Publisher Summary This chapter discusses the effects of cyclic nucleotides and calcium ions
on the Bufo rods. In vertebrate rods, both calcium ions and cyclic nucleotides have been …

1. A cyclic nucleotide phosphodiesterase (EC 3.1. 4.16) has been partially purified from
bovine rod outer segments. The enzyme preparation obtained has a very high specific …

A model is described having the following features: Light induces Ca 2+ release from
vertebrate rod outer segments discs via pores composed of multimeric rhodopsin …