Distribution of radioisotopic beryllium in mice after administration by various routes of injection

Abstract

A 7BeCl2 solution containing 0.5 micrograms Be per mouse was injected subcutaneously, intraperitoneally, intramuscularly, intrathoracically, and intravenously, and distribution was observed for periods up to 1 wk. 7Be was excreted more rapidly following intravenous injection than by the other routes of injection. The amount of Be found in the liver or the spleen was substantial at 1 d after intraperitoneal injection. It increased more in the spleen at 7 d after either intraperitoneal or intrathoracic injection. On the other hand, the amounts of Be stayed almost constant in the kidneys, by the various routes of injection. When injected intrathoracically, the amounts of Be in the heart and the lung were greater than when administered by the other routes of injection. The amounts of Be in the femurs of mice administered by these routes of injection, except with intravenous injection, were greater than in the other organs. The percentage of 7Be in the mineralized bone was 90% of that of 7Be in the femurs when injected intraperitoneally or intrathoracically. However, the ratio of Be in the mineralized bone to that in the bone marrow was 3 to 2. Beryllium had thus a closer affinity for the femurs than for the other organs investigated, with the different modes of administration used. The amount of Be in the entire skeleton was estimated to be substantial. Within the limitations of 1 wk of exposure, the skeleton would appear to be a critical organ. This would suggest that osteosarcomas may occur following administration of Be to laboratory animals for a long-term period.

Measurement of Beryllium in Biological Samples by Accelerator Mass Spectrometry: Applications for Studying Chronic Beryllium Disease

“…Distribution of Be in Biological Tissues. The distribution of 10 Be in tissues dosed with 0.5 µg of 9 Be was similar to that measured by Sakaguchi (14). Total body Be recovered from mice by the AMS method and the 7 Be method was also similar (76 ( 5% as compared to the corresponding Sakaguchi results of 63 ( 2%).…”

“…The 12% intrasample CV of biological samples by AMS is similar to the 9% CV determined in another AMS study for measuring 3 H in biological samples but higher than 2% reported for a new high throughput method for quantifying 14 C by AMS (13,24). In addition, the larger intersample CV as seen in the liver tissue demonstrates the inherent variability that exists between mice in addition to the variability in the sample preparation procedure and the AMS measurements.…”

“…In fact, compounds are absorbed primarily through the portal circulation and therefore pass through the spleen and then the liver before reaching other organs (24). Sakaguchi (14) speculated that 7 Be administered by intraperitoneal injection is attached to the faces of the liver and spleen in the abdomen of the mice and then incorporated. They, therefore, suggest that concentration differences measured in the tissues are due to differences in Be attachment to the organs besides differences in metabolism of Be.…”

“…This sensitivity will allow future studies on the cellular and molecular mechanisms responsible for CBD in humans and is useful for tracing Be in a biological system with the purpose of defining the molecular targets of Be at very low doses. The experiments were designed as a comparison to a 7 Be study in mouse tissues conducted by Sakaguchi (14) to validate our AMS method and determine a Be doseresponse in mouse tissues.…”

Effect of Beryllium Chloride on Porphyrin Metabolism in Pregnant Mice Administered by Subcutaneous Injection

“…An increase in the production of erythroblast cells was observed i n the bone marrow after Be treatment. l O /~ was at 7 d. The percentages of Be retained were at very low levels in the spleen of mice at 1 and 7 d (Sakaguchi et al, 1993). Sakaguchi et al (1 988) previously reported that when 0.5 pg Be was injected into mice subcutaneously, only 0.30h of the administered amount of Be was detected in the blood 30 min after administration, and O .…”