Relationship Between Cycles in Level of Serotonin <i>N</i>‐Acetyltransferase Activity and Cyclic GMP Content of Cultured Chick Pineal Glands

Wainwright, S. D.; Wainwright, Lillian K.

doi:10.1111/j.1471-4159.1984.tb00908.x

Cited by 15 publications

(8 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Less information is available on pineal GC despite the fact that pineal cyclic GMP, like cyclic AMP, also changes with photoperiod (Wainwright and Wainwright, 1984;Quenzer and Volle, 1983).…”

Section: Discussionmentioning

confidence: 97%

“…Recent studies suggest the adrenergic regulation may vary with species; a-adrenergic effects may be more important in sheep (Sugden et al, 1985a) and in chickens (Voisin and Collin, 1986). There are also cyclical changes in pineal cyclic GMP similar to those in cyclic AMP (Wainwright and Wainwright, 1984;Quenzer and Volle, 1983), but GC from pineal has not been characterized. Differences and similarities between results obtained with intact cells and with broken-cell homogenates are discussed here; our results suggest that pineal AC and GC can be selectively and independently regulated by NE.…”

Section: Introductionmentioning

confidence: 96%

See 1 more Smart Citation

Cyclic Nucleotide Metabolism in Pineal Homogenates

Sweat

Carmack

Jewell

1988

Journal of Pineal Research

View full text Add to dashboard Cite

Adenylate cyclase (AC) in pineal particulate fractions from rabbit, rat, cow, and the vole Microtus montanus was stimulated by L-norepinephrine (NE) and L-isoproterenol (ISO). NE stimulation of rabbit and bovine pineal AC was biphasic, with a plateau between 0.01 microM and 1.0 microM and additional stimulation by NE above 1.0 microM. Stimulation by different ISO concentrations gave a typical hyperbolic curve, and optimal stimulation by ISO exceeded that by NE. Melatonin decreased ISO and NE stimulation of AC 10-20%. Although, alpha-adrenergic agonists increase beta-agonist-mediated adenosine-3',5'-cyclic monophosphate (cyclic AMP) accumulation in intact pinealocytes, similar amplification of AC stimulation was not seen with broken-cell preparations. Most (60-70%) pineal guanylate cyclase (GC) was recovered in supernatant fractions after centrifugation of homogenates at 110,000 x g; this soluble GC was unaffected by potential agonists. Low concentrations (0.01-1 nM) of NE, ISO, and phenylephrine (PE) stimulated GC in impure and purified membrane fractions, but each inhibited at concentrations above 10 microM. All concentrations of ISO and NE inhibited GC in the presence of the alpha-agonist PE. Melatonin alone did not affect particulate GC, but L-ISO stimulation was not seen in the presence of equivalent concentrations of melatonin. The in vitro data are consistent with both alpha- and beta-receptor regulation of cyclic nucleotide metabolism in pinealocytes. Endogenous NE may differentially regulate cyclic AMP and guanosine-3',5'-cyclic monophosphate (cyclic GMP) in pineal; low NE concentrations that stimulate GC have only a slight effect on AC, but higher NE concentrations that inhibit GC maximally stimulate AC. Particulate GC and AC also were resolved by equilibrium centrifugation, to give several discrete peaks of enzyme activity. The results support the existence of several forms of AC and GC, which have different responses to adrenergic agonists.

show abstract

Section: Discussionmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 96%

Cyclic Nucleotide Metabolism in Pineal Homogenates

Sweat

Carmack

Jewell

1988

Journal of Pineal Research

View full text Add to dashboard Cite

show abstract

“…Both tissues are high in cGMP (35), and they both synthesize melatonin, the pineal hormone (36). Both tissues are light responsive, although the response is indirect for the pineal (4).…”

Section: Discussionmentioning

confidence: 99%

The major gangliosides of the bovine pineal body

Whalen

Wild

1987

Lipids

View full text Add to dashboard Cite

Acetone powders of fresh-frozen pineals were extracted with chloroform/methanol mixtures. By column chromatography on silicic acid, mild alkaline methanolysis, ion-exchange high performance liquid chromatography and a final thin layer chromatography on silicic acid, the major glycosphingolipids were purified from the extracts of a total of 300 bovine pineal bodies. Chromatographically purified fractions were characterized by gas chromatographic analysis. The most prominent glycosphingolipid appeared to be cerebroside. In addition, five different gangliosides were found in detectable levels. The two major gangliosides have the chromatographic and component characteristics of GD3 and GM3, with disialoganglioside predominating. Gangliosides indistinguishable from purchased standards of GM1 and GD1a were third and fourth, respectively, in amount. The fatty acid profiles of the two lactosyl gangliosides are similar and significantly different from those of the two gangliotetraose gangliosides. The fifth most prominent ganglioside, present at a level of 1.09% of total recovered ganglioside sialic acid, appears to be a novel trisialoganglioside, called GTx. This new molecule has a component ratio of gal:glc:sialic acid:amino sugar of approximately 1:2:3:1. Similarities between bovine pineal and rod outer segments are discussed.

show abstract

“…The contribution of a "normal" serum to our medium is of the order of 5 % of the total calcium. However, neither addition of a large supplement of calcium ions, nor of 1 mM of the chelator ethylene-glycolbis(P-aminoethy1 ether)N,N,N',N'-tetraacetic acid (EGTA), had any effect upon the NAT activities of glands cultured with medium containing "old serum in the dark or under diurnal illumination [Wainwright and Wainwright, 1984a]. * Finally, we chose to examine the effects of ionophore A23187 because of its properties as an ionophore fairly specific for calcium ions.…”

Section: Discussionmentioning

confidence: 99%

Interdependent Effects of the Ionophore A23187 and Serum on the Serotonin N‐Acetyltransferase Activity of Cultured Chick Pineal Glands

Wainwright¹,

Wainwright²

1985

Journal of Pineal Research

Self Cite

View full text Add to dashboard Cite

Marked effects of the ionophore A23187 on the cycle of N-acetyltransferase (NAT) activity in cultured chick pineal glands were observed under three conditions of illumination. However, the effects were qualitatively and quantitatively dependent on the batch of fetal calf serum used in the medium and time of explanation into culture. Ionophore increased the level of NAT activity remaining in glands exposed prematurely to light regardless of the serum used. The ionophore suppressed the "spike" in cyclic GMP content of glands cultured in the dark, and extended the period of maximum cyclic GMP content of glands under diurnal illumination.

show abstract

Relationship Between Cycles in Level of Serotonin N‐Acetyltransferase Activity and Cyclic GMP Content of Cultured Chick Pineal Glands

Cited by 15 publications

References 23 publications

Cyclic Nucleotide Metabolism in Pineal Homogenates

Cyclic Nucleotide Metabolism in Pineal Homogenates

The major gangliosides of the bovine pineal body

Interdependent Effects of the Ionophore A23187 and Serum on the Serotonin N‐Acetyltransferase Activity of Cultured Chick Pineal Glands

Contact Info

Product

Resources

About