Concentration of Striatal Tyramine and Dopamine Metabolism in Diabetic Rats and Effect of Insulin Administration
Bibliographic record
Abstract
Earlier work has shown that diabetic rats possess lower concentrations of brain p-tyrosine; these animals also show a decrease in the rate of accumulation of striatal DOPA after decarboxylase inhibition and an increase in striatal binding sites for dopamine. These findings suggested that diabetic rats show a reduction in the metabolism of brain dopamine. This is an investigation of the effects of streptozotocin-induced (65 mg/kg, intracardially) diabetes on rat striatal concentrations of p-tyrosine, p-tyramine, m-tyramine, dopamine, 3,4-dihydroxyphenylacetic acid and homovanillic acid. Also, the effects of insulin administration (0.5-4 IU/kg, intraperitoneally) to normal and diabetic rats were studied. The onset of diabetes or effect of insulin treatment was determined by the changes produced in blood glucose. Streptozotocin produced a significant reduction in the striatal concentration of p-tyrosine, 3,4-dihydroxyphenylacetic acid and homovanillic acid observed 7 or 14 days after injection. The treatment produced a reduction in p-tyramine and an increase in m-tyramine. Insulin administration significantly increased rat striatal p-tyrosine, p-tyramine, 3,4-dihydroxyphenylacetic acid and homovanillic acid while m-tyramine was decreased. The concentrations of p-tyrosine, dopamine, 3,4-dihydroxyphenylacetic acid and homovanillic acid in the striatum of insulin-treated diabetic rats were within the range of control values. The results indicate that streptozotocin-diabetic rats possess a reduced striatal dopamine metabolism and that this is counteracted by insulin administration. These changes are probably the consequence of changes in the availability of some amino acid precursors and in tyrosine hydroxylase activity.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".