Meta-iodobenzylguanidine derivatives containing a second guanidine moiety.

Published

Journal Article

Radioiodinated meta-iodobenzylguanidine (MIBG) is used in the diagnosis and therapy of various neuroendocrine tumors. To investigate whether an additional guanidine function in the structure of MIBG will yield analogues that may potentially enhance tumor-to-target ratios, two derivatives-one with a guanidine moiety and another with a guanidinomethyl group at the 4-position of MIBG-were prepared. In the absence of any uptake-1 inhibiting conditions, the uptake of 4-guanidinomethyl-3-[(131)I]iodobenzylguanidine ([(131)I]GMIBG) by SK-N-SH cells in vitro was 1.7+/-0.1% of input counts, compared to a value of 40.3+/-1.4% for [(125)I[MIBG suggesting that guanidinomethyl group at the 4-position negated the biological properties of MIBG. On the other hand, 4-guanidino-3-[(131)I]iodobenzylguanidine ([(131)I]GIBG) had an uptake (5.6+/-0.3%) that was 12-13% that of [(125)I]MIBG (46.1+/-2.7%), and the ratio of uptake by control over DMI-treated (nonspecific) cultures was higher for [(131)I]GIBG (20.9+/-0.3) than [(125)I]MIBG itself (15.0+/-2.7). The exocytosis of [(131)I]GIBG and [(125)I]MIBG from SK-N-SH cells was similar. The uptake of [(131)I]GIBG in the mouse target tissues, heart and adrenals, as well as in a number of other tissues was about half that of [(125)I]MIBG. These results suggest that substitution of guanidine functions, especially a guanidinomethyl group, in MIBG structure may not be advantageous.

Full Text

Duke Authors

Cited Authors

  • Vaidyanathan, G; Shankar, S; Affleck, DJ; Alston, K; Norman, J; Welsh, P; LeGrand, H; Zalutsky, MR

Published Date

  • April 2004

Published In

Volume / Issue

  • 12 / 7

Start / End Page

  • 1649 - 1656

PubMed ID

  • 15028258

Pubmed Central ID

  • 15028258

Electronic International Standard Serial Number (EISSN)

  • 1464-3391

International Standard Serial Number (ISSN)

  • 0968-0896

Digital Object Identifier (DOI)

  • 10.1016/j.bmc.2004.01.026

Language

  • eng