Role of dopamine in anterior pituitary tubulin pools in the lactating rat.
In lactating rats, suckling stimulated the in-vitro tubulin assembly of cold-labile pituitary tubulin fraction by about 70%. Domperidone and alpha methyl-p-tyrosine stimulated the pituitary tubulin assembly by 90% and 325%, respectively. In another experiment, pituitaries from a group of lactating rats (no reference to suckling) were processed to obtain cold-labile and cold-stable tubulin fractions; total tubulin fraction was obtained from another group. Tubulin assembly in the total and cold-stable tubulin fractions was 17-20 fold higher compared to cold-labile fraction. Since the cold-stable and total tubulin fractions were extracted with a Ca(2+)-containing buffer, these results suggest that dopamine-induced changes in cytosolic Ca2+ levels modulate pituitary microtubules.
Ravindra
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Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta 30912-2300.
Grosvenor
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CE
D000818:Animals; D002118:Calcium / Q000378:metabolism / Q000494:pharmacology; D004294:Domperidone / Q000494:pharmacology; D004298:Dopamine / Q000502:physiology*; D005260:Female; D007774:Lactation / Q000502:physiology*; D008781:Methyltyrosines / Q000494:pharmacology; D008870:Microtubules / Q000378:metabolism; D010903:Pituitary Gland, Anterior / Q000378:metabolism*; D011388:Prolactin / Q000097:blood; D051381:Rats; D013391:Sucking Behavior; D014404:Tubulin / Q000378:metabolism*; D014446:Tyrosine 3-Monooxygenase / Q000037:antagonists & inhibitors; D019805:alpha-Methyltyrosine
D008781:Methyltyrosines; D014404:Tubulin; D004294:Domperidone; D019805:alpha-Methyltyrosine; D011388:Prolactin; D014446:Tyrosine 3-Monooxygenase; D002118:Calcium; D004298:Dopamine