Monosodium Glutamate Reduces 68Ga-PSMA-11 Uptake in Salivary Glands and Kidneys in a Preclinical Prostate Cancer Model

J Nucl Med. 2018 Dec;59(12):1865-1868. doi: 10.2967/jnumed.118.215350. Epub 2018 Aug 10.

Abstract

We evaluated the ability of monosodium glutamate (MSG) to reduce salivary and kidney uptake of a prostate-specific membrane antigen (PSMA) radioligand without affecting tumor uptake. Methods: LNCaP tumor-bearing mice were intraperitoneally injected with MSG (657, 329, or 164 mg/kg) or phosphate-buffered saline (PBS). Fifteen minutes later, the mice were intravenously administered 68Ga-PSMA-11. PET/CT imaging and biodistribution studies were performed 1 h after administration. Results: Tumor uptake (percentage injected dose per gram [%ID]) was not statistically different between groups, at 8.42 ± 1.40 %ID in the 657 mg/kg group, 7.19 ± 0.86 %ID in the 329 mg/kg group, 8.20 ± 2.44 %ID in the 164 mg/kg group, and 8.67 ± 1.97 %ID in the PBS group. Kidney uptake was significantly lower in the 657 mg/kg group (85.8 ± 24.2 %ID) than in the 329 mg/kg (159 ± 26.2 %ID), 164 mg/kg (211 ± 27.4 %ID), and PBS groups (182 ± 33.5 %ID) (P < 0.001). Salivary gland uptake was lower in the 657 mg/kg (3.72 ± 2.12 %ID) and 329 mg/kg (5.74 ± 0.62 %ID) groups than in the PBS group (10.04 ± 2.52 %ID) (P < 0.01). Conclusion: MSG decreased salivary and kidney uptake of 68Ga-PSMA-11 in a dose-dependent manner, whereas tumor uptake was unaffected.

Keywords: 68Ga-PSMA-11; kidney; monosodium glutamate; prostate-specific membrane antigen; salivary glands.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens, Surface / metabolism
  • Biological Transport, Active / drug effects
  • Cell Line, Tumor
  • Edetic Acid / adverse effects
  • Edetic Acid / analogs & derivatives*
  • Edetic Acid / pharmacokinetics
  • Edetic Acid / therapeutic use
  • Gallium Isotopes
  • Gallium Radioisotopes / adverse effects
  • Gallium Radioisotopes / pharmacokinetics*
  • Gallium Radioisotopes / therapeutic use*
  • Glutamate Carboxypeptidase II / metabolism
  • Humans
  • Kidney / drug effects
  • Kidney / metabolism
  • Kidney / radiation effects
  • Male
  • Mice
  • Mice, Inbred NOD
  • Mice, SCID
  • Oligopeptides / adverse effects
  • Oligopeptides / pharmacokinetics*
  • Oligopeptides / therapeutic use*
  • Positron Emission Tomography Computed Tomography
  • Prostatic Neoplasms / drug therapy
  • Prostatic Neoplasms / metabolism
  • Prostatic Neoplasms / radiotherapy*
  • Radiation-Protective Agents / pharmacology
  • Radiopharmaceuticals / adverse effects
  • Radiopharmaceuticals / pharmacokinetics*
  • Radiopharmaceuticals / therapeutic use*
  • Salivary Glands / drug effects
  • Salivary Glands / metabolism
  • Salivary Glands / radiation effects
  • Sodium Glutamate / pharmacology*
  • Theranostic Nanomedicine / methods
  • Tissue Distribution

Substances

  • Antigens, Surface
  • Gallium Isotopes
  • Gallium Radioisotopes
  • Oligopeptides
  • Radiation-Protective Agents
  • Radiopharmaceuticals
  • gallium 68 PSMA-11
  • Edetic Acid
  • FOLH1 protein, human
  • Glutamate Carboxypeptidase II
  • Sodium Glutamate

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