Possible role of dopamine in the growth inhibitory effect of pentazocine.
Growth inhibitory effect of pentazocine was studied in young rats for a duration of 4 weeks. The animals were subjected to various drug treatments, namely (1) distilled water 0.5 ml/kg s.c.; (2) pentazocine 10 mg/kg s.c.; (3) pentazocine 10 mg/kg s.c. plus metoclopramide 10 mg/kg s.c., and (4) pentazocine 10 mg/kg s.c. plus l-dopa 100 mg/kg s.c. Body weight was taken as a measure for the assessment of growth rate. The results of group 2 were compared with group 1 and that of groups 3 and 4 were compared with group 2. Pentazocine alone markedly inhibited the growth from the second to fourth weeks of treatment. Dopamine antagonist metoclopramide has almost completely prevented the growth inhibitory effect of pentazocine. Combination of l-dopa with pentazocine produced a significant growth inhibition in the first week but subsequently this effect was significantly less marked as compared to that of pentazocine alone. The growth inhibitory effect of pentazocine may possibly be mediated through alterations in dopaminergic mechanisms which are known to exert controlling influence on the release of several of the pituitary hormones.
D000818:Animals; D001835:Body Weight / Q000187:drug effects; D004298:Dopamine / Q000494:pharmacology / Q000502:physiology*; D018492:Dopamine Antagonists; D004357:Drug Synergism; D006128:Growth / Q000187:drug effects*; D007980:Levodopa / Q000009:adverse effects / Q000494:pharmacology; D008787:Metoclopramide / Q000494:pharmacology; D010423:Pentazocine / Q000009:adverse effects* / Q000037:antagonists & inhibitors; D051381:Rats; D011919:Rats, Inbred Strains; D011957:Receptors, Opioid / Q000187:drug effects
D018492:Dopamine Antagonists; D011957:Receptors, Opioid; D007980:Levodopa; D008787:Metoclopramide; D010423:Pentazocine; D004298:Dopamine