Uptake of ³H-labelled Toluidine Blue and Neutral Red in the Parathyroids of the Dog

Abstract

The parathyroid uptake of ³H-labelled toluidine blue and neutral red following i. v. injection in dogs has been studied. At different time intervals, the external parathyroids and samples from reference organs were removed for radioactivity determination. The mean uptake ratio per gram parathyroid/ thyroid of toluidine blue was approximately 3. The mean ratio of para thyroid concentration to that of blood and muscles was 10:1. For neutral red, the mean parathyroid/thyroid ratio was 1.3:1. It is suggested that ⁷⁵Se-labelled toluidine blue may prove useful as a scanning agent for the parathyroids.

Key Words:

• Neutral red
• parathyroids
• toluidine blue
• tritium labelling
• scintigraphy