Nuclear uptake of sex steroid hormones in the cardiovascular system of the baboon

Hormone receptors of the baboon cardiovascular system. Biochemical characterization of aortic and myocardial cytoplasmic progesterone receptors

We used the synthetic progestin R5020 (17 alpha, 21-dimethyl-19-norpregna-4,9-diene-3,20-dione) to characterize cytoplasmic progesterone receptors in baboon (Papio sp.) aorta and myocardium. The relative ability of selected steroids to inhibit binding of radiolabeled R5020 to aortic cytoplasmic progesterone receptors was radioinert R5020, 1.0; progesterone, 0.31; triamcinolone acetonide, 0.06; testosterone, 0.002; estradiol-17 beta, 0.01; and cortisol. 0.001. The relative ability of these same steroids to inhibit binding of radiolabeled R5020 to myocardial cytoplasmic progesterone receptors was, respectively, 1.0, 0.58, 0.21, 0.01, 0.01, and 0.001. Both aortic and myocardial cytoplasmic progesterone receptors migrated as macromolecules with a sedimentation coefficient of 8-9S on low ionic strength linear sucrose gradients. Cytoplasmic binding of R5020 was inactivated by incubation of 37 degrees C. Saturation analysis at 2 degrees C showed aorta and myocardium, respectively, contained 41.6 +/- 16.1 (mean +/- SD) and was 14.0 +/- 2.8 fmol R5020 binding sites/mg cytosol protein. The dissociation constant for R5020 was 2.8 +/- 1.2 nM, aorta, and 2.0 +/- 1.1 nM, myocardium. The presence of progesterone receptors in baboon cardiovascular tissues suggests that progestins may directly influence cardiovascular tissue function.

Localization of 3H-estradiol in the reproductive organs of male and female baboons

The uptake and retention of radiolabeled estradiol by both the male and female reproductive organs were examined in the baboon. Two male and two female baboons were injected intracardially with 1 microgram/kg body weight of 3H-estradiol and two animals, one male and one female, were injected with both labeled and 100 micrograms/kg body weight of unlabeled estradiol. One and a half hours after the injections, the animals were sacrificed and the uterus, cervix, vagina, oviduct, seminal vesicles, and prostate gland were removed and processed for autoradiography. The stratified squamous epithelia of the cervix and vagina demonstrated a light uptake of the label in the germinative, but not in the superficial cell layers. The columnar cells lining the oviduct and uterine glands were labeled, whereas the luminal epithelium of the uterus and the glandular epithelia of the seminal vesicles and prostate gland did not sequester the tritiated steroid. The interstitial cells of all the organs studied demonstrated a moderate to heavy uptake of the radioactivity, whereas the smooth muscle cells were lightly labeled except in the vagina, in which these cells displayed a moderate number of silver grains.

Androgen receptor systems in the brain stem of the primate

The nuclear uptake and retention of [3H]dihydrotestosterone ([3H]DHT) or one of its metabolites was studied in the cerebellum and brain stem of the rhesus monkey. Three days before the injection of the tritiated hormone, we removed both ovaries and the right adrenal gland of 3 female rhesus monkeys under ketamine and halothane or fluothane anesthesia with aseptic surgical procedures. Two days later, we removed the left adrenal gland under similar conditions. Shortly after the second operation, each animal received 100 mg prednisolone sodium succinate. On the day of autopsy, we injected into a femoral vein of each animal 1 microgram of 5 alpha-dihydro[1,2,4,5,6,7-3H]-testosterone (107 Ci/mmol). One of these animals also received an i.v. injection of 100 micrograms/kg body weight of unlabeled DHT to serve as a control. One hour after injection, we rapidly exsanguinated each animal through a femoral venous catheter and perfused the vascular system with approximately 3 1 of Ringer's solution through a femoral arterial catheter. The cerebella and brain stems were removed and processed for autoradiography. Unlike in the rat, nuclear uptake and retention of [3H]DHT was found in both motor and sensory systems of these monkeys and in other areas less well defined. These data indicate that there are major species differences in the nuclear uptake and retention of androgen by the cerebellum and brain stem of rats and primates.

Hormone receptors of the baboon cardiovascular system. Biochemical characterization of myocardial cytoplasmic androgen receptors

Using the synthetic androgen R1881 (17 beta-hydroxy-17alpha-methyl-estra-4, 9, 11-trien-3-one) as probe, we identified cytoplasmic androgen receptors in baboon myocardium. The relative binding affinity of selected steroids for the androgen receptor was R1881, 100%; 5alpha-dihydrotestosterone, 32.6%; testosterone, 29.6%, progesterone, 7.2%; R5020, 1.0%; and estradiol-17beta, 5.8%. The androgen receptor migrated on low ionic strength linear sucrose density gradients as a macromolecule with a sedimentation coefficient of 8.5S. Saturation analysis performed at 2 degrees C (available sites) showed that the androgen receptor content of baboon myocardial cytoplasmic extracts was 5.9 +/- 1.4 fmol/mg protein and that the dissociation constant for R1881 was 1.16 +/- 0.30 nM. These cytoplasmic androgen receptors are indicated to be physiologically functional by previous autoradiographic studies (McGill et al., 1980; McGill and Sheridan, 1981) that showed localization of radioisotope in nuclei of myocardial fibers following injection of baboons with 5 alpha-dihydrotestosterone.

Nuclear uptake of sex steroids in gingiva of the baboon

Influences of sex steroid hormones on the periodontium are documented. Confirmation of the presence and location of receptors for these hormones is important in achieving a more complete understanding of their role in periodontal disease. Biochemical studies have provided evidence of sex steroid receptors in cytosols prepared from gingival tissues, however, no morphologic data are available on the location or specific cell types with receptors. For this study, three mature male and three female baboons received tritiated 5-alpha-dihydrotestosterone (3H-DHT) while three similar males and three females received tritiated estradiol-17 beta (3H-E2). A control animal from each group of three was given an excess of the corresponding unlabeled hormone in addition to the tritiated dose. Gingival specimens were obtained at necropsy as part of a total body study of receptor distribution, and autoradiographs were prepared on emulsion-coated slides. Heavy nuclear uptake was observed in periosteal fibroblasts and scattered fibroblasts of the lamina propria in male given 3H-E2. Females had moderate uptake of E2 in similar but fewer sites than males. There was minimal uptake of 3H-DHT in one male and two females. These data provide additional evidence of steroid receptors in the periodontium and contribute to our understanding of responses of the periodontium to sex steroids.