Cytochemical demonstration of guanylate cyclase activity in retinal photoreceptors with special reference to changes under light and dark adaptation.

Histochemical study on guanylate cyclase activity in the retina of developing rat.

“…2). Thereafter, the reaction was found in the tip of the outer segments and retinal pigment epithelium as previously observed in the adult rats (6).…”

“…An invagination of the outer segment plasma membranes was reported (7), but, on the other hand, it was counterclaimed that these lamellar membranes could be traced to the small vesicles or smooth endoplasmic reticulum (5). In the cytochemical studies of guanylate cyclase activity, however, remarkable reactions could be observed, not on the small vesicles or endoplasmic reticulum but on the plasmalemma of the outer segments during the initial postnatal weeks and also in the adult stage (6). This might be an interesting result, when we consider the origin of the disk membranes.…”

“…The sites of guanylate cylcase (6) and cyclic nucleotidephosphodiesterase (9) have already been studied utilizing newly developed cytochemical methods (2,8). Histochemically, uniquely rich guanylate cyclase activity was found to be restricted to the tip of the outer segments and the microvilli of the retinal pigment epithelium (6). The aim of the present study is to elucidate the localization of this enzyme activity in the developing rat retina with special emphasis on the formation of outer segments.…”

Lead citrate method of guanylate cyclase and its application to tissue receiving rapid freeze substitution fixation.

“…In 1975, the first attempt on GCase demonstration was reported (53,54). GCase activity was reported in the rat retina and some other tissues (19,20,29,40,63,69). However, LeMay and Jarett (1975) claimed that in the use of the lead ion as capture agent in ACase histochemistry, the lead ion not only brings about a complete inhibition of the enzyme activity, at the concentration in the reaction medium, but it further acts to catalize the non enzymatic degradation of the substrate (31).…”

Localization of cyclase and cyclic nucleotide phosphodiesterase activities in retinal pigment epithelial cells of the guinea pig.

“…Recently, to avoid several fundamental drawbacks of the conventional methods, new histo-and cytochemical methods for these enzyme activities were introduced for cyclases by Fujimoto et al (14) and for cyclic nucleotide phosphodiesterase by Ueno et al (33,34). Several studies utilizing these methods have successfully demonstrated the fine structural localizations of the enzyme activities in various tissues (14,30,33,34). The aim of the present study is to ultracytochemically examine the localization of these cyclic nucleotides synthesizing and degrading enzyme activities in situ utilizing the newly developed methods.…”