The Mammalian Pineal Expresses the Cone but Not the Rod Cyclic GMP Phosphodiesterase

Abstract

To determine the presence of cone or rod cyclic GMP phosphodiesterase (EC 3 .1 .4 .17) in the mammalian pineal, extracts from adult rat and bovine pineals were injected onto a Mono Q anion-exchange HPLC column and eluted with an NaCl linear gradient . Fractions were immunoadsorbed with monoclonal antibodies specific to rod and cone phosphodiesterases (ROS-1) and to calmodulin-phosphodiesterase complexes (ACC) . Profiles were assayed with 10 pmol/L [ 3 H]cyclic GMP in the presence of calcium -calmodulin, histone, or trypsin . Rat and bovine pineals displayed a single peak of activity recognized by ROS-1, which corresponded to the activity of the cone but not to the rod in bovine retina . ROS-1 immunoadsorbed -80% of the activity in the 60-day-old rat pineal but only 26% of the activity in bovine pineal . ACC immunoadsorbed the remaining activity in both species . Western blot analysis of rat pineal extracts revealed three polypeptides of -87, 15, and 10 kDa when probed with a rod/cone phosphodiesterase-specific antiserum . The specific activity of the cone-like phosphodiesterase in 10-day-old rat pineals was twice that of this isozyme in the bovine retina and 150 times that in the bovine pineal . The specific activity of phosphodiesterase in rat pineals decreased with age . We conclude that an enzyme with biochemical and antigenic characteristics similar to cone, but distinct from rod phosphodiesterase, is present in bovine and rat pineals .

Expression and role of phosphodiesterase 6 in the chicken pineal gland

“…2000). These recent findings are in agreement with previous studies indicating that a large number of phototransduction markers can be detected by in situ hybridization in the neonatal rat pineal (Blackshaw and Snyder 1997), that PDE6 activity can be detected in this organ (Carcamo et al . 1995) and that norepinephrine decreases opsin immunoreactivity in cultured rat pinealocytes (Araki and Tokunaga 1990; Araki 1992).…”

“…This response could be observed in a narrow developmental window and was obliterated by noradrenergic input to the pineal gland (Tosini et al 2000). These recent ®ndings are in agreement with previous studies indicating that a large number of phototransduction markers can be detected by in situ hybridization in the neonatal rat pineal (Blackshaw and Snyder 1997), that PDE6 activity can be detected in this organ (Carcamo et al 1995) and that norepinephrine decreases opsin immunoreactivity in cultured rat pinealocytes (Araki and Tokunaga 1990;Araki 1992). Therefore, elucidating the mechanism of pineal photosensitivity may not only improve our knowledge of pineal physiology in non mammals, but also our understanding of the development of pineal function in the mammalian embryo.…”

Expression of C‐Type Natriuretic Peptide in the Bovine Pineal Gland

“…CNP does not appear to influence melatonin secretion. In combination with the lack of effect of 8-Br-cGMP on melatonin release (Maronde et a!., 1995), it is obvious that CNP-mediated cGMP may subserve other intracellular activities, e.g., an influence on synaptic ribbon turnover (Spessert et al, 1992), cGMP phosphodiesterases (Carcamo et a!., 1995), or cGMPdependent ion channels (Dryer and Henderson, 1991;Distler et al, 1994;Chik et al, 1995;Schaad et a!., 1995). Otherwise, it is conceivable that a cross-talk between the CNP and the recently described nitric oxide pathway (Spessert, 1993;Spessert et a!., 1993;Klein, 1993, 1995;Lin et a!., 1994) may exist in the pinea!…”

Induction of photosensitivity in neonatal rat pineal gland

“…Rhodopsin immunoreactivity and rhodopsin mRNAs have been demonstrated in several mammalian species (11)(12)(13)(14)(15)(16). Other data suggest the presence of cone cGMP phosphodiesterase in neonatal rat pineals (17), and a recent paper using in situ hybridization techniques has reported the presence in newborn rats and mice of many components necessary for functional phototransduction (18).…”