| | 1 | Author
| Stylianos Tsakiris3, Panagiota Kouniniotou-Krontiri3, KleopatraH. Schulpisb, JohnC. Stavridis3 | Requires cookie* | | | Title
| L-Phenylalanine Effect on Rat Brain Acetylcholinesterase and Na+,K+-ATPase  | | | | Abstract
| The effect of different L-phenylalanine (Phe) concentrations (0 .1 -1 2 .1 m M) , on acetylcho linesterase (A C h E) and N a+,K +-ATPase activities of brain homogenate and pure enzymes, was investigated at 37 °C. A C h E and Na+,K +-ATPase activities were determined according to Ellman G. -6 1 3) respectively, after preincubation with Phe. A C h E activity in brain homogenate or in pure eel E.electricus enzyme showed a decrease, which reached up to 18% with concentrations of 0 .9 -1 2 .1 m M . Brain homogenate N a+,K +-A TPase activity showed an increase 1 6 -6 5 % with 0 .2 4 -0 .9 mM of Phe, while an activity increase of 6 0 -6 5 % appeared with 0 .9 -1 2 .1 mM of Phe. Pure en zyme activity (from porcine cerebral cortex) was not affected by high Phe concentrations, while it was increased by low concentrations. The above results suggest: a) A direct effect of Phe on A C h E , b) A direct effect of low Phe concentrations and an indirect effect of high ones on Na+,K +-ATPase. | | | |
Reference
| Z. Naturforsch. 53c, 163 (1998); received September 22/D ecem ber 15 1997 | | | |
Published
| 1998 | | | |
Keywords
| L-Phenylalanine, R at Brain, Acetylcholinesterase, N a+, K +-ATPase, Mg2+-ATPase | | | |
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| default:Reihe_C/53/ZNC-1998-53c-0163.pdf | | | | Identifier
| ZNC-1998-53c-0163 | | | | Volume
| 53 | |
| 2 | Author
| Stylianos Tsakiris, Panagoula Angelogianni, JohnC. Stavridis | Requires cookie* | | | Title
| Effect of Aging on the Activities of Acetylcholinesterase, Na+, K+-ATPase and Mg2+-ATPase in Rat Pituitary and Hypothalamus | | | | Abstract
| Acetylcholinesterase (A C h E), N a+, K +-ATPase and Mg2+-A TPase activities were esti mated in homogenised rat pituitary and hypothalamus of 4-and 22-month-old rats. A C hE activity was not altered in the pituitary of aged com pared to adult rats, while it was found decreased by about 40% in the hypothalamus. N a+,K +-A TPase activity remained stable in the hypothalamus, while it was decreased by about 38% in the pituitary. Mg2+-A TPase activ ity remained unchanged in the hypothalamus, but was increased by about 83% in the pitu itary. This pituitary N a+, K +-ATPase inactivation may result in pathological mood and de creased neural excitability and metabolic energy production in aged animals.The age-related alterations of A C h E , Na+, K +-ATPase and Mg2+-A TPase activities may reflect changes in secretion and responses of some hormones of pituitary and hypothalamus. | | | |
Reference
| Z. Naturforsch. 53c, 168 (1998); received O ctober 13/O ctober 31 1997 | | | |
Published
| 1998 | | | |
Keywords
| Aging, R at Pituitary, Rat Hypothalamus, Acetylcholinesterase, N a+, K +-ATPase, Mg2+-ATPase | | | |
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| default:Reihe_C/53/ZNC-1998-53c-0168.pdf | | | | Identifier
| ZNC-1998-53c-0168 | | | | Volume
| 53 | |
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