Fraction of lactotrophs that proliferate during oestrus

Range ≈2.5 %
Organism Rat Rattus norvegicus
Reference Seilicovich A. Cell life and death in the anterior pituitary gland: role of oestrogens. J Neuroendocrinol. 2010 Jul22(7):758-64. doi: 10.1111/j.1365-2826.2010.02010.x p.760 right column 2nd paragraphPubMed ID20456596
Primary Source [43] Hashi A, Mazawa S, Kato J, Arita J. Pentobarbital anesthesia during the proestrous afternoon blocks lactotroph proliferation occurring on estrus in female rats. Endocrinology. 1995 Oct136(10):4665-71 DOI: 10.1210/endo.136.10.7664687PubMed ID7664687
Method Primary source abstract: "Female rats revealing regular 4-day estrous cycles were injected ip with the thymidine analog 5-bromo-2'-deoxyuridine (BrdU) 3 h before decapitation to label DNA-replicating cells. Dispersed anterior pituitary cells obtained from these rats were stained for PRL [Lactotroph] and BrdU with a double labeling immunofluorescence technique. The rate of lactotroph proliferation was represented by the BrdU-labeling index (BrdU-labeled lactotrophs as a percentage of total lactotrophs counted). Lactotrophs from rats injected with BrdU at 1000 h showed a high BrdU-labeling index of 2.6% on estrus, whereas they showed almost undetectable levels of the BrdU-labeling index during the other stages of the estrous cycle."
Comments P.760 right column 2nd paragraph: "Lactotrophs are the anterior pituitary cell subpopulation with the highest rate of proliferation followed by somatotrophs, corticotrophs and gonadotrophs (ref 11). During the oestrous cycle, proliferative activity in anterior pituitary cells occurs only during oestrus and requires stimulation by hypothalamic factors and/or the sensitising action of E2 (refs 2, 8, 39). Approximately 2.5% of lactotrophs proliferate at this stage of the oestrous cycle (primary source) and therefore a similar number of these cells might die to maintain the size of the lactotroph subpopulation."
Entered by Uri M
ID 115289