In vivo characteristics of IBZM in rat brains: An agent for quantitative SPECT imaging of D2 dopamine receptors - A basis for semiquantitative measurement of the receptor density using equilibrium analysis

H. Toyama, K. Matsumura, H. Nakashima, M. Ichise, M. Kurami, T. Nakagawa, H. Maeda, A. Takeuchi, S. Koga

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

To establish a basis for semiquantitative SPECT measurements of the D2 dopamine receptor density using equilibrium analysis, we evaluated in vivo kinetic properties of 125I-IBZM in rat brains. We measured percent uptakes (% dose/g) of 125I-IBZM in the striatum, frontal cortex, and cerebellum. We made these regional measurements at 15, 30, 45, 60, 90, and 120 minutes after injection, respectively. The specific striatal uptake, which is the uptake difference between striatum and frontal cortex or cerebellum, showed a transient equilibrium phase at 60 min. Theoretically, with these 'reversible' D2 receptor binding ligands, the tracer-uptake ratio of the striatum-to-frontal cortex or cerebellum during the equilibrium phase provides an estimate of binding potential (Bound/Free = B(max)/K(d)). Our experiment showed that these ratio increased with time after bolus injection of the tracer. Striatum to frontal cortex or cerebellum ratios which were calculated with pooled data (n = 12) at 60 minutes in equilibrium phase showed nearly constant values (C.V. = 12.3% and 13.5%, respectively). Although measuring the striatum to frontal cortex or cerebellum ratios near equilibrium phase by bolus injection of the tracer which are widely used in human SPECT study could not exactly signify the binding potential, those ratios at fixed time after injection would be reliable for semiquantitative index.

Original languageEnglish
Pages (from-to)1117-1120
Number of pages4
JournalKakuigaku
Volume31
Issue number9
Publication statusPublished - 01-01-1994

Fingerprint

Dopamine D2 Receptors
Frontal Lobe
Single-Photon Emission-Computed Tomography
Cerebellum
Brain
Injections
Corpus Striatum
3-iodo-2-hydroxy-6-methoxy-N-((1-ethyl-2-pyrrolidinyl)methyl)benzamide
Ligands

All Science Journal Classification (ASJC) codes

  • Radiology Nuclear Medicine and imaging

Cite this

Toyama, H. ; Matsumura, K. ; Nakashima, H. ; Ichise, M. ; Kurami, M. ; Nakagawa, T. ; Maeda, H. ; Takeuchi, A. ; Koga, S. / In vivo characteristics of IBZM in rat brains : An agent for quantitative SPECT imaging of D2 dopamine receptors - A basis for semiquantitative measurement of the receptor density using equilibrium analysis. In: Kakuigaku. 1994 ; Vol. 31, No. 9. pp. 1117-1120.
@article{c0b4281a7c90435ba7d64dd14cbad628,
title = "In vivo characteristics of IBZM in rat brains: An agent for quantitative SPECT imaging of D2 dopamine receptors - A basis for semiquantitative measurement of the receptor density using equilibrium analysis",
abstract = "To establish a basis for semiquantitative SPECT measurements of the D2 dopamine receptor density using equilibrium analysis, we evaluated in vivo kinetic properties of 125I-IBZM in rat brains. We measured percent uptakes ({\%} dose/g) of 125I-IBZM in the striatum, frontal cortex, and cerebellum. We made these regional measurements at 15, 30, 45, 60, 90, and 120 minutes after injection, respectively. The specific striatal uptake, which is the uptake difference between striatum and frontal cortex or cerebellum, showed a transient equilibrium phase at 60 min. Theoretically, with these 'reversible' D2 receptor binding ligands, the tracer-uptake ratio of the striatum-to-frontal cortex or cerebellum during the equilibrium phase provides an estimate of binding potential (Bound/Free = B(max)/K(d)). Our experiment showed that these ratio increased with time after bolus injection of the tracer. Striatum to frontal cortex or cerebellum ratios which were calculated with pooled data (n = 12) at 60 minutes in equilibrium phase showed nearly constant values (C.V. = 12.3{\%} and 13.5{\%}, respectively). Although measuring the striatum to frontal cortex or cerebellum ratios near equilibrium phase by bolus injection of the tracer which are widely used in human SPECT study could not exactly signify the binding potential, those ratios at fixed time after injection would be reliable for semiquantitative index.",
author = "H. Toyama and K. Matsumura and H. Nakashima and M. Ichise and M. Kurami and T. Nakagawa and H. Maeda and A. Takeuchi and S. Koga",
year = "1994",
month = "1",
day = "1",
language = "English",
volume = "31",
pages = "1117--1120",
journal = "Kaku igaku. The Japanese journal of nuclear medicine",
issn = "0022-7854",
publisher = "Japanese Society of Nuclear Medicine",
number = "9",

}

In vivo characteristics of IBZM in rat brains : An agent for quantitative SPECT imaging of D2 dopamine receptors - A basis for semiquantitative measurement of the receptor density using equilibrium analysis. / Toyama, H.; Matsumura, K.; Nakashima, H.; Ichise, M.; Kurami, M.; Nakagawa, T.; Maeda, H.; Takeuchi, A.; Koga, S.

In: Kakuigaku, Vol. 31, No. 9, 01.01.1994, p. 1117-1120.

Research output: Contribution to journalArticle

TY - JOUR

T1 - In vivo characteristics of IBZM in rat brains

T2 - An agent for quantitative SPECT imaging of D2 dopamine receptors - A basis for semiquantitative measurement of the receptor density using equilibrium analysis

AU - Toyama, H.

AU - Matsumura, K.

AU - Nakashima, H.

AU - Ichise, M.

AU - Kurami, M.

AU - Nakagawa, T.

AU - Maeda, H.

AU - Takeuchi, A.

AU - Koga, S.

PY - 1994/1/1

Y1 - 1994/1/1

N2 - To establish a basis for semiquantitative SPECT measurements of the D2 dopamine receptor density using equilibrium analysis, we evaluated in vivo kinetic properties of 125I-IBZM in rat brains. We measured percent uptakes (% dose/g) of 125I-IBZM in the striatum, frontal cortex, and cerebellum. We made these regional measurements at 15, 30, 45, 60, 90, and 120 minutes after injection, respectively. The specific striatal uptake, which is the uptake difference between striatum and frontal cortex or cerebellum, showed a transient equilibrium phase at 60 min. Theoretically, with these 'reversible' D2 receptor binding ligands, the tracer-uptake ratio of the striatum-to-frontal cortex or cerebellum during the equilibrium phase provides an estimate of binding potential (Bound/Free = B(max)/K(d)). Our experiment showed that these ratio increased with time after bolus injection of the tracer. Striatum to frontal cortex or cerebellum ratios which were calculated with pooled data (n = 12) at 60 minutes in equilibrium phase showed nearly constant values (C.V. = 12.3% and 13.5%, respectively). Although measuring the striatum to frontal cortex or cerebellum ratios near equilibrium phase by bolus injection of the tracer which are widely used in human SPECT study could not exactly signify the binding potential, those ratios at fixed time after injection would be reliable for semiquantitative index.

AB - To establish a basis for semiquantitative SPECT measurements of the D2 dopamine receptor density using equilibrium analysis, we evaluated in vivo kinetic properties of 125I-IBZM in rat brains. We measured percent uptakes (% dose/g) of 125I-IBZM in the striatum, frontal cortex, and cerebellum. We made these regional measurements at 15, 30, 45, 60, 90, and 120 minutes after injection, respectively. The specific striatal uptake, which is the uptake difference between striatum and frontal cortex or cerebellum, showed a transient equilibrium phase at 60 min. Theoretically, with these 'reversible' D2 receptor binding ligands, the tracer-uptake ratio of the striatum-to-frontal cortex or cerebellum during the equilibrium phase provides an estimate of binding potential (Bound/Free = B(max)/K(d)). Our experiment showed that these ratio increased with time after bolus injection of the tracer. Striatum to frontal cortex or cerebellum ratios which were calculated with pooled data (n = 12) at 60 minutes in equilibrium phase showed nearly constant values (C.V. = 12.3% and 13.5%, respectively). Although measuring the striatum to frontal cortex or cerebellum ratios near equilibrium phase by bolus injection of the tracer which are widely used in human SPECT study could not exactly signify the binding potential, those ratios at fixed time after injection would be reliable for semiquantitative index.

UR - http://www.scopus.com/inward/record.url?scp=0028148755&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0028148755&partnerID=8YFLogxK

M3 - Article

C2 - 7967197

AN - SCOPUS:0028148755

VL - 31

SP - 1117

EP - 1120

JO - Kaku igaku. The Japanese journal of nuclear medicine

JF - Kaku igaku. The Japanese journal of nuclear medicine

SN - 0022-7854

IS - 9

ER -