Topic
Pinealocyte
About: Pinealocyte is a research topic. Over the lifetime, 1605 publications have been published within this topic receiving 55609 citations.
Papers published on a yearly basis
Papers
More filters
TL;DR: In vitro transient transfections of retinoblastoma and neuroblastoma cells and in vivo experiments with transgenic Xenopus laevis indicate that −1783/+101 and −156/+101 IRBP gene fragments directed expression predominantly to the retina and pineal, with minor neuronal expression elsewhere.
19 citations
TL;DR: It is concluded that basal phosphat enzyme activity, probably phosphoprotein phosphatase‐1, plays an important role in the regulation of L‐type Ca2+ channel currents in rat pinealocytes by counteracting protein kinase C‐mediated phosphorylation.
Abstract: In the present study, the role of phosphoprotein phosphatase in the regulation of L-type Ca2+ channel currents in rat pinealocytes was investigated using the whole-cell version of the patch-clamp technique. The effects of three phosphatase inhibitors, calyculin A, tautomycin, and okadaic acid, were compared. Although all three inhibitors were effective in inhibiting the L-type Ca2+ channel current, calyculin A was more potent than either tautomycin or okadaic acid, suggesting the involvement of phosphoprotein phosphatase-1. To determine the kinase involved in the regulation of these channels, cells were pretreated with H7 (a nonspecific kinase inhibitor), H89 (a specific inhibitor of cyclic AMP-dependent kinase), KT5823 (a specific inhibitor of cyclic GMP-dependent kinase), or calphostin C (a specific inhibitor of protein kinase C). Pretreatment with either H7 or calphostin C decreased the inhibitory effect of calyculin A on the L-type Ca2+ channel current. In contrast, pretreatment with H89 or KT5823 had no effect on the inhibition caused by calyculin A. Based on these observations, we conclude that basal phosphatase activity, probably phosphoprotein phosphatase-1, plays an important role in the regulation of L-type Ca2+ channel currents in rat pinealocytes by counteracting protein kinase C-mediated phosphorylation.
19 citations
TL;DR: The results of these studies suggest that opioidergic receptors exist on pinealocytes and they are involved in stimulating the activity of N‐acetyltransferase and the synthesis of melatonin, thereby regulating the physiology of mammalian pineal gland.
Abstract: Previous studies in our laboratories have identified a single population of opioid receptors in bovine pineal gland, which we have chosen to characterize further on pinealocytes isolated from the cow and rat pineal gland. The bovine pinealocytes isolated by trypsinization or mechanical manipulation revealed receptor density (Bmax) values of 206.95 +/- 131.15 and 220.34 +/- 11.80 fmol/mg protein, respectively, and dissociation equilibrium constant (Kd) values of 1.93 +/- 0.48 and 1.96 +/- 0.21 nM, respectively. The rat pinealocytes cultured for 7 days exhibited a [3H]diprenorphine binding site of 56 fmol/10(6) cells. Morphine (100 microM) enhanced the activity of N-acetyltransferase and the level of melatonin in rat pineal gland in culture incubated for 21 hr. The results of these studies suggest that opioidergic receptors exist on pinealocytes and they are involved in stimulating the activity of N-acetyltransferase and the synthesis of melatonin, thereby regulating the physiology of mammalian pineal gland.
19 citations
01 Jan 1980
TL;DR: Physiological investigations suggest the presence of light receptors, thermoreceptors, as well as sodium and glucose receptors in the wall of the diencephalon, and Morphological data likewise indicate the occurrence of sensory cells in the hypothalamus.
Abstract: Physiological investigations suggest the presence of light receptors, thermoreceptors, as well as sodium and glucose receptors in the wall of the diencephalon (22). Morphological data likewise indicate the occurrence of sensory cells in the hypothalamus (12); for instance, the so-called liquor-contacting neurons (13, 14, 19) and the coronet cells of the vascular sac of fishes (16). The photoreceptor cells of the retina and the similarly built pinealocytes develop from the diencephalon as well.
19 citations
TL;DR: The location of VIP‐containing fibers in the capsule of the pineal gland indicates that the fibers originate from perikarya located in a peripheral ganglion.
Abstract: Vasoactive intestinal peptide (VIP)-like immunoreactive nerve fibers were demonstrated by peroxidase antiperoxidase (PAP) inmmunohistochemistry to be distributed throughout the entire pineal gland of the sheep. VIP-containing fibers were observed along the blood vessels, penetrating into the gland from the pial capsule and also in the capsule itself. Some fibers left the perivascular position and entered the pineal parenchyma, where they were located among pinealocytes. This suggested that the VIPergic fibers might influence both pinealocytes and blood vessels of the gland. The location of VIP-containing fibers in the capsule of the pineal gland indicates that the fibers originate from perikarya located in a peripheral ganglion.
19 citations