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Biomedical subjects

D Grant

Publications and source records attributed to D Grant.

At least 325 records · Page 18Linked to original sources

Homing orientation by olfaction in newts (Taricha rivularis).

Newts displaced after perfusion of the olfactory epithelium with formaldehyde failed to orient toward home, whereas control animals subjected to oral perfusion with formaldehyde oriented as readily as did untreated controls. Newts with surgically extirpated olfactory nerves failed to home unless their nerves had regenerated. These results strongly suggest a critical role for olfaction in homing behavior.

Animals↗

Metabolism of mangafodipir trisodium (MnDPDP), a new contrast medium for magnetic resonance imaging, in beagle dogs.

The metabolism of MnDPDP (manganese(II) N,N'-dipyridoxylethylenediamine-N,N'-diacetate-5,5'-bis(phosphate) was studied in dogs after intravenous infusion for 12.5 min with either 10, 30 or 100 mumol MnDPDP/kg b.w. HPLC analyses of plasma samples obtained 1, 5 and 30 min after the end of infusion revealed that MnDPDP was rapidly dephosphorylated to MnDPMP (manganese(II) N,N'-dipyridoxylethylenediamine-N,N'-diacetate-5-phosphate) and MnPLED (manganese(II) N,N'-dipyridoxylethylenediamine-N,N'-diacetate), with simultaneous transmetallation to the corresponding zinc metabolites ZnDPDP, ZnDPMP and ZnPLED. In the low-dose group, the parent compound MnDPDP was present at the lowest concentration compared to the metabolites at the first sampling time point, 1 min after the end of infusion, whereas MnPLED was the main metabolic. At 30 min post-infusion ZnPLED was the main metabolite. The medium- and high-dose groups showed a similar metabolic pattern. In the high-dose group, MnPLED was the main metabolite at all sampling time points. The estimated plasma half-life of total ligand was 20 min, and it was dose-independent with an apparent volume of distribution of 0.2 l/kg. The rate of dephosphorylation was similar to the rate of transmetallation, and both were dose-independent. However, calculations of the total Mn and Zn ligands indicated that the apparent plasma elimination was dose-dependent. The half-life for total Mn ligands which is a combination of both metabolism and elimination, were 10 and 20 min at 10 and 100 mumol/kg, respectively. The half-life for total Zn ligands which is the half-life for rate of formation of Zn ligands, were 40 and 65 min at 10 and 100 mumol/kg, respectively. No sex differences in metabolic pattern were observed in any of the three dosage groups.

Animals↗