We examined the effects of parathyroid hormone (PTH) applied in physiological doses on the entry of 45Ca2+, release of 3H-GABA, and also on the contents of 1,2-diacylglycerol (DAG) and cAMP in preparations of synaptosomes obtained from the brain cortex of mongrel albino rats. It was found that PTH intensified 45Ca2+ entry in the synaptosomes. Potassium depolarization of the synaptosomal membranes did not considerably influence the entry of these ions under the influence of PTH. At the same time, evoked 45Ca2+ entry was greater than the spontaneous one in control preparations. Spontaneous release of 3H-GABA increased under the influence of PTH. At the same time, there was no additional release of 3H-GABA under depolarization conditions. Applications of PTH increased the contents of cAMP and DAG in the examined nerve terminals. It is supposed that increases in the levels of the above messengers predetermine activation of the corresponding protein kinases and phosphorylation of membrane proteins. This, finally, leads to realization of the hormonal signal, namely intensified release of the neurotransmitter.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
D. N. Khudaverdyan and A. S. Ter-Markosyan, “Parathyroid hormone, a modulator of the functional activity of neurons,” Biokhimiya, 65, No. 2, 207–212 (2000).
D. N. Khudaverdyan, Mechanisms of parathyroprival motor disorders, Abstract of dissertation for Dr. Med. degree, Yerevan (1984).
F. Hajos, “An improved method for the preparation of synaptosomal fraction of high purity,” Brain Res., 93, No. 5, 485–489 (1975).
D. N. Khudaverdyan, A. S. Ter-Markosyan, and Yu. V. Tadevosyan, “Initiation of the phosphoinositide cycle in synaptosomes by parathyroid hormone,” Biokhimiya, 62, No. 10, 1295–1299 (1997).
G. M. Ajay, K. M. Amitsu, and H. A. Keit, “Regulation of cytosolic calcium by parathyroid hormone and oscillation of cytosolic calcium in fibroblasts from normal and pseudohypoparathyroid patients,” Endocrinol., 128, No. 6, 2825–2836 (1991).
G. M. Dolson, M. K. Hise, and E. J. Weinman, “Relationship among parathyroid hormone, cAMP, and calcium on proximal tubule sodium transport,” Am. J. Renal Physiol., 249, No. 3, F409–F416 (1985).
D. N. Khudaverdyan, A. S. Ter-Markosyan, and A. R. Sargsyan, “On the mechanism of action of parathyroid hormone on the functional activity of the nerve cells,” Neirokhimiya, 8, No. 2, 210–215 (1989).
P. G. Kostyuk, Ye. A. Lukyanetz, A. S. Ter-Markosyan, and D. N. Khudaverdyan, “Stimulation of the calcium conductance in nerve cells by parathyroid hormone,” Neirofiziologiya, 22, No. 3, 373–380 (1990).
P. G. Kostyuk, E. A. Lukyanetz, and A. S. Ter-Markosyan, “Parathyroid hormone enhances calcium current in snail neurones; stimulation of the effect by phorbol esters,” Pflügers Arch., 420, 146–152 (1992).
Ye. S. Severin and M. N. Kochetkova, Role of phosphorylation in the regulation of cell activity, Nauka, Moskow (1985).
J. Lin, M. Sugimori, R. R. Linas, and P. Greengard, “Effect of synapsin I and calcium-calmodulin-dependent protein kinase II on spontaneous neurotransmitter release in the squid giant synapse,” Proc. Natl. Acad. Sci. USA, 87, No. 21, 8257–8261 (1990).
P. V. Nguyen and N. H. Woo1, “Regulation of hippocampal synaptic plasticity by cyclic AMP dependent proteinkinases,” Prog. Neurobiol., 71, No. 6, 401–437 (2003).
F. Fiumara, S. Giovedì, A. Menegon, et al., “Phosphorylation by cAMP-dependent protein kinase is essential for synapsin-induced enhancement of neurotransmitter release in invertebrate neurons,” J. Cell Sci., 117, No. 21, 5145–5154 (2004).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Ter-Markosyan, A.S. Effects of Parathyroid Hormone on Functional Activity of the Synaptosomes. Neurophysiology 44, 493–495 (2012). https://doi.org/10.1007/s11062-012-9325-6
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11062-012-9325-6