Axoplasmic transport of substances in motoneuronal axons of the spinal cord in old age
| Autor: | O.K. Kulchitsky, V.I. Marcinko, Vladimir V. Frolkis, S.A. Tanin, A.V. Yasechko |
|---|---|
| Rok vydání: | 1985 |
| Předmět: |
Testosterone propionate
Male medicine.medical_specialty Aging Central nervous system Biology Axonal Transport chemistry.chemical_compound Internal medicine medicine Cyclic AMP Colchicine Animals Testosterone Motor Neurons Muscles Spinal cord Axons Rats Electrophysiology Endocrinology medicine.anatomical_structure chemistry Spinal Cord Axoplasmic transport biology.protein Sodium Fluoride Estradiol dipropionate 2 4-Dinitrophenol Energy Metabolism Spinal Nerve Roots Dinitrophenols Developmental Biology Neurotrophin |
| Zdroj: | Mechanisms of ageing and development. 29(1) |
| ISSN: | 0047-6374 |
| Popis: | Seven to eight microliters of aqueous solution of spl-[14C]Leucine (spec. act. 339 mCi/mmol) were introduced in the zone of ventral horn (L5—L6) of the spinal cord of adult (8–12 months) and old (26–28 months) rats. The radioactivity of various parts of the corresponding ventral roots was measured 1–2.5 h thereafter. Labelled substances (including protein) were found to migrate with fast flow in adult rats at the rate of 408 ± 10.9 and 380 ± 22 mm/24 h. respectively, as compared with 217 ± 11.3 and 200 ± 40 mm/24 h in old rats. The axoplasmic flow slows down in old rats with the increase of distance from the neuronal body. Uncoupling of oxidation and phosphorylation by the administration of 2,4-dinitrophenol, inhibition of glycolysis with NaF, hypoxemia produce more marked deceleration of axoplasmic flow in old rats, while small doses of NaF accelerate the flow, which correlates with the rise of cAMP in ventral roots. Sex steroids accelerate significantly the rate of axoplasmic flow. There is a marked increase in the rate due to the adminsitration of estradiol dipropionate in old rats and due to testosterone propionate in adult animals. Changes in resting membrane potential and direct excitability thresholds of some muscles following colchicine blockade of axoplasmic transport are less marked in old rats that evidences for the weakening of neurotrophic control in old age. |
| Databáze: | OpenAIRE |
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