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Biomedical subjects

W E Stumpf

Publications and source records attributed to W E Stumpf.

At least 235 records · Page 13Linked to original sources
PubMed1975

Autoradiographic localization of radioactivity from [3-H]oxytocin in the rat mammary gland and oviduct.

[3-H]Oxytocin was incubated in vitro with pieces of oviduct and mammary gland and the tissue were subjected to autoradiography. Radioactivity was localized only in smooth muscle cells of the oviduct and in regions of mammary tissue where myoepithelial cells are found. In contrast, radioactivity was not concentrated in any region of skeletal muscle, a nontarget tissue for oxytocin. The localization of radioactivity in oviduct and mammary cells was absent when the tissues were incubated with [3-H]oxytocin and an excess of unlabeled oxytocin. These findings provide evidence for the presence of specific and high affinity receptors for oxytocin in its target tissues.

Animals↗
PubMed1975

Synergism between prolactin and ovarian hormones of DNA synthesis in rats mammary gland.

Autoradiography with [30H] thymedine has been used to measure the rate of DNA synthesis in the mammary epithelium of hypophysectomized-ovariectomized rats under the influence of estradiol, progesterone, and prolactin. Controls and animals treated with estradiol did not increase [3-H] thymidine incorporation, while progesterone alone had a slight stimulatory effect. Prolactin alone stimulated some [3-H] thymidine uptake in ductal and alveolar epithelium, but when combined with either estradiol or progesterone synergistic effects were observed. Estradiol with prolactin stimulated incorporation primarily in the ductal epithelium, whereas progesterone with prolactin stimulated both ductal and alveolar epithelium.

Animals↗
PubMed1973

Neurons of the hypothalamus concentrate (3H)progesterone or its metabolites.

Selective concentration of [(1)H]progesterone or its metabolites is observed in nuclei of neurons in certain hypothalamic regions of the guinea pig 15 minutes after injection of [1,2,6,7-(3)H]progesterone, by use of dry-mount autoradiography. Highest concentrations of progestin target neurons exist in the nucleus arcuatus, the nucleus preopticus periventricularis, and the nucleus preopticus suprachiasmaticus. Previous administration of unlabeled progesterone inhibits the nuclear concentration of radioactivity, but cortisol has no effect. Estradiol priming enhances the nuclear uptake of radioactivity. The results demonstrate the existence of progestin target sites in the hypothalamus and suggest a direct action of progestin on certain hypothalamic structures.

Animals↗