Radioiodinated Exendin-4 Is Superior to the Radiometal-Labelled Glucagon-Like Peptide-1 Receptor Probes Overcoming Their High Kidney Uptake - Fig 2

<p><b>Internalization (A) and binding (B) curves for [Nle</b>^<b>14</b><b>,</b>^<b>125</b><b>I-Tyr</b>^<b>40</b><b>-NH</b>_<b>2</b><b>]Ex-4 agonist and [Nle</b>^<b>14</b><b>,</b>^<b>125</b><b>I-Tyr</b>^<b>40</b><b>-NH</b>_<b>2</b><b>]Ex(9–39) antagonist in Ins-1E cells.</b> The plots show the percentage of specifically internalized and specifically bound peptide versus time. Values are mean±standard deviation of triplicate measurements.</p

<i>In vitro</i> saturation binding data.

<p>The graphs show the percentage of specifically bound [Nle¹⁴,¹²⁵I-Tyr⁴⁰-NH₂]Ex-4 (A) or [Nle¹⁴,¹²⁵I-Tyr⁴⁰-NH₂]Ex(9–39) (B) per 1×10⁶ cells after incubation of Ins-1E cells with increasing amounts of the peptide. Values are mean±standard error of triplicate measurements.</p

Mass dependence of [Nle¹⁴,¹²⁵I-Tyr⁴⁰-NH₂]Ex-4 biodistribution in nude mice bearing Ins-1E xenografts 1 h p.i.

<p>Mass dependence of [Nle¹⁴,¹²⁵I-Tyr⁴⁰-NH₂]Ex-4 biodistribution in nude mice bearing Ins-1E xenografts 1 h p.i.</p

Radioiodinated Exendin-4 Is Superior to the Radiometal-Labelled Glucagon-Like Peptide-1 Receptor Probes Overcoming Their High Kidney Uptake - Fig 3

<p><b>Radio-HPLC showing the radiochemical purity of formulated [Nle</b>^<b>14</b><b>,</b>^<b>124</b><b>I-Tyr</b>^<b>40</b><b>-NH</b>_<b>2</b><b>]Ex-4 without (A) and with co-injection of cold reference [Nle</b>^<b>14</b><b>,</b>^<b>127</b><b>I-Tyr</b>^<b>40</b><b>-NH</b>_<b>2</b><b>]Ex-4 (B)</b>. UV-and radio-detectors were in series, resulting in a lag time of about 15 sec for the radiotrace. Numbers in the chromatograms refer to the peak retention time in minutes.</p

Biodistribution of [Nle¹⁴,¹²⁵I-Tyr⁴⁰-NH₂]Ex(9–39) in mice bearing Ins-1E xenografts.

<p>Biodistribution of [Nle¹⁴,¹²⁵I-Tyr⁴⁰-NH₂]Ex(9–39) in mice bearing Ins-1E xenografts.</p

[Nle¹⁴,¹²⁴I-Tyr⁴⁰-NH₂]Ex-4 tumor time-activity curves.

<p>The curves are derived from the PET image analysis and show the tumor uptake of [Nle¹⁴,¹²⁴I-Tyr⁴⁰-NH₂]Ex-4 versus time.</p