Abstract
The role of microtubules in the thyrotropin- or adenosine 3',5' cyclic monophosphate (cyclic AMP)-stimulated accumulation of cytoplasmic colloid droplets and secretion of iodine from the mouse thyroid gland has been investigated by means of different classes of agents that affect the stability of microtubules. The onset of inhibition of secretion by colchicine, the uptake of colchicine-3H by thyroid lobes, and the binding of colchicine-3H to thyroidal soluble protein are shown to have similar time courses Colloid droplet accumulation is also inhibited and does not readily resume upon removal of colchicine from the medium. This appears to be due to the slow washout of the drug (t ½ ∼ hr). Thyroids contain a soluble colchicine-binding protein that resembles microtubule proteins of other tissues with respect to apparent Km for colchicine, pH optimum, and stability characteristics Colchicine analogues inhibit iodine secretion and colchicine binding in a parallel manner and as a function of their antimitotic potencies. Microtubule-stabilizing agents such as hexylene glycol and D2O also inhibit secretion. Thus, inhibition of thyroid secretion by antimitotic agents appears to be mediated by an effect on microtubules. The inhibitory locus of colchicine inhibition occurs after the generation of cyclic AMP, since stimulation of secretion by this nucleotide is blocked by colchicine, whereas thyroid-stimulating hormone—induced accumulation of cyclic AMP is not affected. Thus, the functioning microtubule appears to play a role in the induction of colloid endocytosis.
Full Text
The Full Text of this article is available as a PDF (727.1 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Borisy G. G., Taylor E. W. The mechanism of action of colchicine. Binding of colchincine-3H to cellular protein. J Cell Biol. 1967 Aug;34(2):525–533. doi: 10.1083/jcb.34.2.525. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Borisy G. G., Taylor E. W. The mechanism of action of colchicine. Colchicine binding to sea urchin eggs and the mitotic apparatus. J Cell Biol. 1967 Aug;34(2):535–548. doi: 10.1083/jcb.34.2.535. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ensor J. M., Munro D. S. A comparison of the in-vitro actions of thyroid-stimulating hormone and cyclic 3',5'-adenosine monophosphate on the mouse thyroid gland. J Endocrinol. 1969 Mar;43(3):477–485. doi: 10.1677/joe.0.0430477. [DOI] [PubMed] [Google Scholar]
- Gillespie E., Levine R. J., Malawista S. E. Histamine release from rat peritoneal mast cells: inhibition by colchicine and potentiation by deuterium oxide. J Pharmacol Exp Ther. 1968 Nov;164(1):158–165. [PubMed] [Google Scholar]
- Gilman A. G. A protein binding assay for adenosine 3':5'-cyclic monophosphate. Proc Natl Acad Sci U S A. 1970 Sep;67(1):305–312. doi: 10.1073/pnas.67.1.305. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gilman A. G., Rall T. W. Factors influencing adenosine 3',5'-phosphate accumulation in bovine thyroid slices. J Biol Chem. 1968 Nov 25;243(22):5867–5871. [PubMed] [Google Scholar]
- Heersche J. N., Fedak S. A., Aurbach G. D. The mode of action of dibutyryl adenosine 3',5'-monophosphate on bone tissue in vitro. J Biol Chem. 1971 Nov 25;246(22):6770–6775. [PubMed] [Google Scholar]
- Inoué S., Sato H. Cell motility by labile association of molecules. The nature of mitotic spindle fibers and their role in chromosome movement. J Gen Physiol. 1967 Jul;50(6 Suppl):259–292. [PMC free article] [PubMed] [Google Scholar]
- Kirkpatrick J. B., Hyams L., Thomas V. L., Howley P. M. Purification of intact microtubules from brain. J Cell Biol. 1970 Nov 1;47(2):384–394. doi: 10.1083/jcb.47.2.384. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nagayama A., Dales S. Rapid purification and the immunological specificity of mammalian microtubular paracrystals possessing an ATPase activity. Proc Natl Acad Sci U S A. 1970 Jun;66(2):464–471. doi: 10.1073/pnas.66.2.464. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Olmsted J. B., Carlson K., Klebe R., Ruddle F., Rosenbaum J. Isolation of microtubule protein from cultured mouse neuroblastoma cells. Proc Natl Acad Sci U S A. 1970 Jan;65(1):129–136. doi: 10.1073/pnas.65.1.129. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Pastan I., Roth J., Macchia V. Binding of hormone to tissue: the first step in polypeptide hormone action. Proc Natl Acad Sci U S A. 1966 Dec;56(6):1802–1809. doi: 10.1073/pnas.56.6.1802. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Williams J. A., Berens S. C., Wolff J. Thyroid secretion in vitro: inhibition of TSH and dibutyryl cyclic-AMP stimulated 131-I release by Li+1. Endocrinology. 1971 Jun;88(6):1385–1388. doi: 10.1210/endo-88-6-1385. [DOI] [PubMed] [Google Scholar]
- Wolff J., Jones A. B. Inhibition of hormone-sensitive adenyl cyclase by phenothiazines. Proc Natl Acad Sci U S A. 1970 Feb;65(2):454–459. doi: 10.1073/pnas.65.2.454. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Zor U., Kaneko T., Lowe I. P., Bloom G., Field J. B. Effect of thyroid-stimulating hormone and prostaglandins on thyroid adenyl cyclase activation and cyclic adenosine 3',5',-monophosphate. J Biol Chem. 1969 Oct 10;244(19):5189–5195. [PubMed] [Google Scholar]