Randomized Trial of Motivational Interviewing to Prevent Early Childhood Caries in Public Housing.

INTRODUCTION: Caries experience among preschool-age children has remained relatively unchanged for the past 2 decades, despite recently documented decreases in untreated decay. OBJECTIVES: In a community-based cluster-randomized controlled trial, a motivational interviewing (MI) intervention administered to primary caregivers was hypothesized to reduce caries increment over 2 y as compared with controls, among children aged 0 to 5 y at baseline living in public housing. METHODS: Public housing residents, who served as interventionists, were trained in MI with a focus on early childhood caries prevention. All 26 eligible public housing developments were randomized to either control (quarterly clinical examinations, fluoride varnish applications, toothbrush/toothpaste, and educational brochures) or intervention (same procedures as control plus MI counseling). Quarterly MI sessions were delivered in English or Spanish over 2 y, audio recorded, and assessed for treatment fidelity. The primary outcome was the increment in dmfs (decayed, missing, and filled tooth surfaces) as assessed by clinical examination at baseline, 12 mo, and 24 mo. Secondary outcomes included caregiver oral health knowledge and child oral health behaviors (child toothbrushing and sugar-sweetened beverage intake). Baseline characteristics were compared between groups and adjusted for housing-site clusters. Longitudinal outcomes were analyzed with mixed models. RESULTS: A total of 1,065 children (49% female, 55% non-White, 61% Hispanic, 89% below poverty level, n = 686 control) and their caregivers were enrolled. During 2 y of follow-up, the mean dmfs increment increased in both groups; however, there were no statistically significant group differences at 24 mo or group × time interactions. The mean increase in intervention caregivers' knowledge was significantly greater than that of control, F(2, 1,593) = 3.48, P = 0.0310, but there were no significant intervention effects on caregiver-reported child sugar-sweetened beverage intake or child toothbrushing. CONCLUSION: MI counseling plus intensive caries prevention activities resulted in knowledge increases but did not improve oral health behaviors or caries increment (ClinicalTrials.gov NCT01205971). KNOWLEDGE TRANSFER STATEMENT: When viewed in light of the findings from the companion Pine Ridge study and other recent MI studies, the results of this study suggest that when the complex disease of early childhood caries is addressed in high-risk populations, MI is not effective, and alternative approaches are warranted.

Randomized Trial of Motivational Interviewing to Prevent Early Childhood Caries in American Indian Children.

INTRODUCTION: In a randomized controlled trial, the effectiveness of motivational interviewing (MI) combined with enhanced community services (MI + ECS) was compared with ECS alone for reducing dental caries in American Indian children on the Pine Ridge Reservation. The intervention was developed and delivered with extensive tribal collaboration. METHODS: A total 579 mother-newborn dyads were enrolled and randomized to the MI + ECS and ECS groups. They were followed for 36 mo. Four MI sessions were provided, the first shortly after childbirth and then 6, 12, and 18 mo later. Both groups were exposed to ECS, which included public service announcements through billboards and tribal radio, as well as broad distribution of brochures on behavioral risk factors for early childhood caries (ECC), toothbrushes, and toothpaste. MI impact was measured as decayed, missing, and filled tooth surfaces (dmfs). Secondary outcomes included decayed surfaces, caries prevalence, and maternal oral health knowledge and behaviors. Modified intention-to-treat analyses were conducted. Eighty-eight percent of mothers completed at least 3 of 4 MI sessions offered. RESULTS: After 3 y, dmfs was not significantly different for the 2 groups (MI + ECS = 10, ECS = 10.38, P = 0.68). In both groups, prevalence of caries experience was 7% to 9% after 1 y, 35% to 36% at 2 y, and 55% to 56% at 3 y. Mean knowledge scores increased by 5.0, 5.3, and 5.9 percentage points at years 1, 2, and 3 in the MI + ECS group and by 1.9, 3.3, and 5.0 percentage points in the ECS group (P = 0.03), respectively. Mean maternal oral health behavior scores were not statistically significantly different between the treatment arms. CONCLUSION: In summary, the MI intervention appeared to improve maternal knowledge but had no effect on oral health behaviors or on the progression of ECC (ClinicalTrials.gov NCT01116726). KNOWLEDGE TRANSFER STATEMENT: The findings of this study suggest that motivational interviewing focusing on parental behaviors may not be as effective as previously hoped for slowing the development of childhood caries in some high-risk groups. Furthermore, social factors may be even more salient determinants of oral health than what we previously supposed, perhaps interfering with the capacity to benefit from behavioral strategies that have been useful elsewhere. The improvement of children's oral health in high-risk populations characterized by poverty and multiple related life stresses may require more holistic approaches that address these formidable barriers.

Androgen receptor content of the normal and hyperplastic canine prostate.

A procedure was developed for measurement of androgen receptors in cytoplasmic extracts of prostates from intact dogs. The protocol utilized exchange saturation analysis at 15 degrees C employing the synthetic androgen R1881 (17beta-hydroxy-17alpha-methylestra-4,9,11-trien-3-one) as the ligand probe and quantitatively detected total cytoplasmic androgen receptor (R(c), androgen-free receptor, and R(c)A, androgen-occupied receptor) present at the initiation of the assay. This protocol was employed in conjunction with a tissue mince saturation analysis procedure (for quantitation of nuclear androgen receptor) to quantitate total androgen receptor content of normal and hyperplastic prostates obtained from young (2.5- or 4.6-yr old) and aged (12.5-yr old) purebred dogs of known birth date. The total cytoplasmic androgen receptor content (picomoles per prostate) of hyperplastic prostates was 4.6-fold greater than that of normal prostates. The total nuclear androgen receptor content of hyperplastic prostates (picomoles per prostate measured in crude nuclear preparations) was either 5.0- (4.6-yr-old dogs) or 7.8-fold (2.5-yr-old dogs) greater than that of normal prostates. However, androgen receptor content per cell was identical for hyperplastic and normal canine prostates, with the exception that nuclear androgen receptor was diminished in prostates from 2.5-yr-old dogs. The cell content per gram dry weight was identical for hyperplastic and normal canine prostates. We conclude that canine prostate hyperplasia is characterized by coordinate proliferation of androgen receptor-positive and androgen receptor-negative cells and is not a consequence of increased accumulation of 5alpha-dihydrotestosterone due to proliferation of androgen receptors per prostate cell.

Fluoride varnish efficacy in preventing early childhood caries.

To determine the efficacy of fluoride varnish (5% NaF, Duraphat, Colgate) added to caregiver counseling to prevent early childhood caries, we conducted a two-year randomized, dental-examiner-masked clinical trial. Initially, 376 caries-free children, from low-income Chinese or Hispanic San Francisco families, were enrolled (mean age +/- standard deviation, 1.8 +/- 0.6 yrs). All families received counseling, and children were randomized to the following groups: no fluoride varnish, fluoride varnish once/year, or fluoride varnish twice/year. An unexpected protocol deviation resulted in some children receiving less active fluoride varnish than assigned. Intent-to-treat analyses showed a fluoride varnish protective effect in caries incidence, p < 0.01. Analyzing the number of actual, active fluoride varnish applications received resulted in a dose-response effect, p < 0.01. Caries incidence was higher for 'counseling only' vs. 'counseling + fluoride varnish assigned once/year' (OR = 2.20, 95% CI 1.19-4.08) and 'twice/year' (OR = 3.77, 95% CI 1.88-7.58). No related adverse events were reported. Fluoride varnish added to caregiver counseling is efficacious in reducing early childhood caries incidence.

Spontaneous adenocarcinomas of the ventral prostate of aged A X C rats.

Spontaneous adenocarcinomas of the ventral prostate were present in 7 of 41 aged (34- to 37-month-old), virgin, untreated male A X C rats. The only consistent gross evidence of possible neoplastic involvement was intraprostate hemorrhage. The principally intraglandular neoplasms were composed of markedly anaplastic epithelial cells which retained a moderate propensity to form glandular patterns. The nuclei of the neoplastic cells were pleomorphic, vesiculated, enlarged, and hyperchromatic. Mitotic figures were frequent. Interglandular connective tissue was invaded in one rat; however, metastases were not demonstrated.

C19-steroid metabolism by spontaneous adenocarcinoma of the A X C rat ventral prostate.

Specimens of ventral prostate from 37- to 46-month-old Andradurin-treated A X C rats demonstrated three primary morphologic patterns, each being divisible into two sub-groups based upon the extent of glandular alteration. The principal groups were: group 1, hyperplasia; group 2, atypical hyperplasia; and group 3, adenocarcinoma. The secondary classifications were: subgroup (+), few glands involved; and subgroup (++), most glands involved. Multiple parameters of ventral prostate testosterone metabolic potential failed to distinguish the morphologically diverse prostate specimens of groups (1+). 1(++), 2(+), 2(++), and 3(+) which predominantly metabolized testosterone to 5alpha-reduced 17beta-hydroxysteroids. By contrast, testosterone metabolism by ventral prostate specimens predominantly composed of neoplastic epithelium, group 3(++), was distinct from all other prostate specimens. The distinguishing feature was a shift to more prominent elaboration of 17-ketosteroids, principally delta4-androstenedione, and a cteroids. The change in this biochemical parameter of prostate epithelial cell function was indicated to be an early manifestation of the neoplastic transformation.

A x C rat prostate adenocarcinoma: initial characterization of testosterone regulation of hormone receptors of cultured cancer cells and derived tumors.

A x C rat prostate cancer cells were established in continuous culture. The polygonal epithelial cells had granular cytoplasm and well-defined cell margins, contained round to oval nuclei with prominent nucleoli, and were tumorigenic when inoculated into A x C male rats. The tumors produced by the injected prostate cancer cells grew as well-vascularized, solid, cribriform adenocarcinomas. The rat prostate cancer cells and derived tumors contained cytoplasmic and nuclear androgen receptors and prolactin receptors. Androgen regulation of prolactin receptor content and androgen receptor distribution in A x C rat prostate cancer cells were comparable to those of the normal ventral prostate gland. These studies suggest that the A x C rat prostate cancer cells and tumors may represent a unique model for studies of hormonal regulation of prostate cancer cell behavior.

Oncorna-like viruses in baboon prostate tissue.

Oncorna-like virus particles were observed in prostate tissue of 2 of 11 baboons inoculated 3 years previously with a chemical carcinogen. There were no indications, however, of any relationship between the carcinogen and the development of virus particles. Biopsy specimens from the animals showed no evidence of neoplasia, and electron microscopic examination suggested that this virus should be categorized as a B-type oncornavirus.

Differential androgen modulation of AXC/SSh rat prostate cancer cell proliferation in vitro and its antagonism by antiandrogen.

We examined androgen modulation of proliferation of clonally derived AXC/SSh rat prostate cancer cells. C-family cells were maintained on medium without addition of androgens. D-family cells were maintained on medium containing 10(-7) M 5 alpha-dihydrotestosterone and T-family cells were maintained on medium containing 10(-7) M testosterone. Proliferation of all AXC/SSh prostate cancer cell lines during propagation on media containing fetal bovine serum was not altered by changes in media testosterone concentration through the range 10(-6) to 10(-9) M. Similarly, proliferation of C- or D-family cell lines, during propagation on media containing steroid depleted, charcoal stripped fetal bovine serum, was not altered by changes in media testosterone concentration through the range 10(-6) to 10(-9) M. By contrast, proliferation of T-family cell lines during propagation on charcoal stripped fetal bovine serum was modulated by androgens; effects were androgen concentration dependent and maximum at 10(-8) to 10(-7) M. Androgens decreased T5 cell proliferation rate and diminished achievable saturation density, whereas T1 cell proliferation rate was increased by androgens. In contrast, T6 cell proliferation rate was unaffected by androgens; however, saturation density was increased. Effects were antagonized by the antiandrogen RU 23908, Anandron, establishing androgen specificity of testosterone or 5 alpha-dihydrotestosterone mediated changes in proliferation.

Differences in responsiveness of clonally derived AXC/SSh rat prostate cancer cells to secreted or prototypic mitogens.

AXC/SSh rat prostate cancer cells elaborate heat-sensitive, heparin-binding mitogens which include members of the fibroblast growth factor (FGF)-like family of growth factors. The quantity of FGF-like growth factors, relative to total growth factor production, was cell line specific as was prostate cancer cell response to secreted or the prototypic mitogens basic FGF (bFGF), acidic FGF (aFGF), or epidermal growth factor (EGF). C3 cell proliferation, assayed either by cell counting or thymidine incorporation, was not affected by mitogens secreted by C3, D1, T1, or T5 prostate cancer cells or by bFGF, aFGF, or EGF. In contrast, C3, D1, T1, or T5 cell-secreted mitogens enhanced proliferation of T1 and T5 cells, and proliferation of D1, T1, and T5 cells was enhanced by bFGF, aFGF, and EGF. D1 cell response to prototypic mitogens was 3- to 12-fold less than that of T1 or T5 cells. By comparison, the NRKF cell response to prototypic mitogens was qualitatively comparable but quantitatively greater than that of rat prostate cancer cells. The relative and absolute bFGF or aFGF concentrations necessary for half-maximum stimulation of prostate cancer or normal rat kidney fibroblast cell thymidine incorporation were comparable to that known to effect half-maximum increase in proliferation of mesoderm-derived cells. Similarly, the EGF concentration required for half-maximum prostate cancer or normal rat kidney fibroblast cell thymidine incorporation was comparable to that known to effect half-maximum fibroblast thymidine incorporation or granulosa cell proliferation. Our data establish that prostate cancer cell response to prototypic mitogens is representative of that of nonneoplastic cells and imply that C3 cell insensitivity to prostate cancer cell or prototypic mitogens represents defects in cellular response mechanisms. The basis for C3 cell unresponsiveness or D1 cell-diminished responsiveness remains to be elaborated.

Biochemical and morphological characterization of clonal AXC rat prostate cancer cells.

We used three heterogeneous parental cultures of LSC-AXC rat prostate cancer cells: LSC-AXC-C/O, cells maintained on culture medium; LSC-AXC-D/O, cells maintained on culture medium containing 10(-7) M 5 alpha-dihydrotestosterone; and LSC-AXC-T/O, cells maintained on culture medium containing 10(-7) M testosterone, to isolate clonally derived cell lines. Eleven of 15 clonal cell lines were tumorigenic when inoculated into intact male AXC rats. Eight tumorigenic clonal cell lines were selected for further evaluation, and all were found to possess features characteristic of secretory epithelium, as judged by light and electron microscopy. All parental cell lines and the eight selected clonal cell lines contained cytoplasmic and nuclear androgen receptors. Total receptor content was 131 +/- 61 (S.D.), 43 +/- 32, and 274 +/- 96 fmol/100 micrograms of DNA, respectively, for C-, D-, and T-cells. The differences were significant (p less than 0.05). Androgen receptor content of young mature or senescent AXC rat ventral prostate, respectively, is 518 +/- 58 and 266 +/- 40 fmol/100 micrograms of DNA. Since chromosomal analysis established that LSC-AXC prostate cancer cells are hypotriploid, androgen receptor content per cell in C- and T-cells is indicated to be either greater than or equal to that of senescent AXC rat ventral prostate, the tissue in which the original adenocarcinoma arose. Parental and clonal cell lines contained 5 alpha-reductase activity. There were significant differences (p less than 0.05) in both total reductase activity and metabolite distribution. Consequently, the intracellular content of testosterone metabolites was cell line specific. All characterized cell lines contained a higher concentration (p less than 0.05) of APase activity than did young mature or senescent AXC rat ventral prostate. In 6 of 11 cell lines, prostate-secretory APase concentration exceeded (p less than 0.05) that of AXC rat ventral prostate. However, the relative content of secretory APase compared to total APase in carcinoma cells consistently was less (p less than 0.05) than that of AXC rat ventral prostate. These studies document the establishment of clonal AXC rat prostate adenocarcinoma cell lines which have retained important morphological and phenotypic markers characteristic of differentiated prostate epithelium. Since these cells are tumorigenic and represent a spectrum of retained differentiated phenotypic markers, they should be particularly useful for in vivo and in vitro studies of hormonal regulation of prostate cancer cell behavior.

Human prostate androgen receptor quantitation: effects of temperature on assay parameters.

When cytoplasmic extracts of human prostatic tissues were split to permit quantitation of total androgen receptor (RCT) content by saturation analysis at 15 degrees and 2 degrees, we observed that 30% (10 of 32) of the specimens yielded statistically increased values for RCT following incubation at 15 degrees as compared to 2 degrees. Considering only those specimens (13 of 32) showing statistically differentiated RCT yield, 77% (10 of 13) yielded greater RCT content following incubation at 15 degrees. The families of association constants (Ka) obtained for RCT determinations at 2 degrees and 15 degrees were not statistically differentiated. The increased yield of RCT content determined at 15 degrees was 95% (mean) and 20 to 350% (range). Nuclear androgen receptor content determined at 15 degrees was greater for 25% (2 of 8) of the patient specimens when compared to split determinations performed at 2 degrees. Incubation of nuclear extracts at 15 degrees resulted in a significant 3-fold reduction in receptor Ka for methyltrienolone (R1881). This did not appear to affect assay precision. These studies showed that incubation at 15 degrees is preferable to incubation at 2 degrees for quantitation of RCT and nuclear androgen receptor content by saturation analysis. Single saturating dose determinations of RCT consistently yielded underestimates. The extent of underestimate was variable from specimen to specimen and was both ligand concentration and assay temperature dependent. Our data suggest that results of single saturating dose determinations of RCT require cautious interpretation.

Inability of cytoplasmic or nuclear androgen receptor content or distribution to distinguish benign from carcinomatous human prostate.

We used exchange saturation analysis at 15 degrees to quantitate total cytoplasmic and nuclear androgen receptor content of 70 patient specimens. Cytoplasmic androgen receptor contents (fmol/mg DNA) for eight specimens of clinically benign hyperplasia, 14 specimens of histologically hyperplastic prostate obtained at cystoprostatectomy, and carcinomatous and noncarcinomatous prostate obtained at radical prostatectomy for prostatic carcinoma, 48 specimens, respectively, were 830 +/- 165 (mean +/- S.E.), 890 +/- 445, 955 +/- 240, and 750 +/- 95. Nuclear androgen receptor contents of these same specimens, respectively, were 275 +/- 40, 235 +/- 30, 345 +/- 25, and 350 +/- 30; whereas, the values of the cytoplasmic/nuclear receptor content, respectively, were 3.25 +/- 0.55, 3.05 +/- 0.80, 2.50 +/- 0.50, and 2.80 +/- 0.40. Multiway analyses of variance of these cross-sectional data showed that there was no significant difference (p greater than 0.05) between group mean values. This result principally reflects the fact that the families of values for the four tissue groups were highly heterogenous with broad overlap. The results would not appear to be unduly influenced by carcinomatous epithelial cell content of the specimens, because cytoplasmic and nuclear androgen receptor content were not related to specimen carcinomatous epithelial cell content. Paired analyses of receptor content in carcinomatous and noncarcinomatous prostate specimens from the same prostate showed enhanced or unchanged receptor content in 58% (cytoplasmic) and 62% (nuclear) of specimens. Our studies show that cross-sectional analyses of androgen receptor content fail to distinguish carcinomatous prostate from noncarcinomatous prostate. However, paired analyses of these tissues from the same gland identify distinguishing differences. The clinical relevance of these observations remains to be examined.

A Cluster-Randomized, Community-Based, Tribally Delivered Oral Health Promotion Trial in Navajo Head Start Children.

The authors tested the effectiveness of a community-based, tribally delivered oral health promotion (OHP) intervention (INT) at reducing caries increment in Navajo children attending Head Start. In a 3-y cluster-randomized trial, we developed an OHP INT with Navajo input that was delivered by trained Navajo lay health workers to children attending 52 Navajo Head Start classrooms (26 INT, 26 usual care [UC]). The INT was designed as a highly personalized set of oral health-focused interactions (5 for children and 4 for parents), along with 4 fluoride varnish applications delivered in Head Start during academic years of 2011 to 2012 and 2012 to 2013. The authors evaluated INT impact on decayed, missing, and filled tooth surfaces (dmfs) increment compared with UC. Other outcomes included caries prevalence and caregiver oral health-related knowledge and behaviors. Modified intention-to-treat and per-protocol analyses were conducted. The authors enrolled 1,016 caregiver-child dyads. Baseline mean dmfs/caries prevalence equaled 19.9/86.5% for the INT group and 22.8/90.1% for the UC group, respectively. INT adherence was 53% (i.e., ≥3 child OHP events, ≥1 caregiver OHP events, and ≥3 fluoride varnish). After 3 y, dmfs increased in both groups (+12.9 INT vs. +10.8 UC; P = 0.216), as did caries prevalence (86.5% to 96.6% INT vs. 90.1% to 98.2% UC; P = 0.808) in a modified intention-to-treat analysis of 897 caregiver-child dyads receiving 1 y of INT. Caregiver oral health knowledge scores improved in both groups (75.1% to 81.2% INT vs. 73.6% to 79.5% UC; P = 0.369). Caregiver oral health behavior scores improved more rapidly in the INT group versus the UC group (P = 0.006). The dmfs increment was smaller among adherent INT children (+8.9) than among UC children (+10.8; P = 0.028) in a per-protocol analysis. In conclusion, the severity of dental disease in Navajo Head Start children is extreme and difficult to improve. The authors argue that successful approaches to prevention may require even more highly personalized approaches shaped by cultural perspectives and attentive to the social determinants of oral health (ClinicalTrials.gov NCT01116739).

Aging in the AXC rat: differential effects of chronic testosterone treatment on restoration of diminished prostate L-ornithine decarboxylase and S-adenosyl-L-methionine decarboxylase activities.

L-Ornithine decarboxylase (ODC) activity per 100 mg prostate was diminished 88% and S-adenosyl-L-methionine decarboxylase (AMDC) activity similarly ws diminished 57% in the ventral prostate of aged (26-month-old) as compared to that of young (3.8-month-old) AXC rats. Dorsolateral prostate ODC activity was too low to be reliably quantitated. Dorsolateral prostate AMDC activity per 100 mg prostate was diminished 55% in aged AXC rats. The age-related declines in prostate ODC and AMDC were not attributable to changes in the properties of the enzymes in aged AXC rats compared to young rats. There also was no evidence for an age-related production of inhibitors or inactivators of these prostate enzymes. The sensitivities of prostate ODC and AMDC to orchiectomy were comparable in young and aged AXC rats. Treatment of aged AXC rats with exogenous testosterone did not enhance ventral prostate AMDC activity per 100 micrograms DNA, but it did elevate dorsolateral prostate AMDC activity per 100 micrograms DNA to levels indistinguishable from those characteristic of untreated young AXC rats and caused a 303% increase in ventral prostate ODC activity per 100 micrograms DNA. However, ODC activity per 100 micrograms DNA in the ventral prostate of testosterone-treated aged rats was only 49% of that characteristic of untreated young AXC rats. We have identified three categories of age-related changes in prostatic enzyme activity: 1) decline fully reversible by exogenous testosterone, 2) decline partially reversible by exogenous testosterone, and 3) decline not reversible by exogenous testosterone. These alterations may reflect age-related changes in androgen-regulated prostate gene function.

Aging in the AXC rat: equivalence of the rates of inactivation of l-ornithine decarboxylase and S-adenosyl-L-methionine decarboxylase in prostate of young and aged rats.

The incorporation of leucine into proteins of ventral and dorsolateral prostates of young (3- to 4-month-old) and aged (24- to 26-month-old) AXC rats was examined in vivo. We established that a single injection of cycloheximide (500 micrograms/100 g BW) maintained 91% (ventral) or 86% (dorsolateral) inhibition of protein synthesis in prostates of young AXC rats and 90% (ventral) or 88% (dorsolateral) inhibition of protein synthesis in prostates of aged AXC rats through at least 120 min post injection. During cycloheximide-maintained inhibition of protein synthesis, the rate of inactivation of ventral prostate L-ornithine decarboxylase (ODC) or S-adenosyl-L-methionine decarboxylase (AMDC) activity and dorsolateral prostate AMDC activity was comparable in the prostates of young and aged AXC rats. The absence of an age-related change in the rate of inactivation of prostatic ODC or AMDC activity provides additional evidence that the age-related decrease in prostatic ODC and AMDC activities reported in the companion article may reflect altered androgen regulation of prostatic gene activity.

Sexual dimorphism characterizes steroid hormone modulation of rat aortic steroid hormone receptors.

Quantification of aortic androgen and estrogen receptor content and distribution in AXC/SSh rats established that the total androgen receptor content in intact young mature males (mean +/- SD, 55 +/- 13 fmol/mg DNA) was indistinguishable (P greater than 0.05) from that in proestrous females (50 +/- 3 fmol/mg DNA). However, 60% of male aortic androgen receptors were in the nuclear fraction, whereas all proestrous female aortic androgen receptors were in the cytoplasmic fraction. The total aortic estrogen receptor content of intact young mature males (70 +/- 16 fmol/mg DNA) was indistinguishable (P greater than 0.05) from that of proestrous (92 +/- 12) or diestrous (77 +/- 4) females. However, 50% of proestrous female aortic estrogen receptors were in the nuclear fraction, whereas male or diestrous female aortic estrogen receptors were restricted to the cytoplasmic fraction. To assess estrogen receptor function, we characterized aortic cytoplasmic progesterone receptors and established that the receptor content of intact male aortae (101 +/- 3 fmol/mg DNA) was not significantly different (P greater than 0.05) from that of diestrous female aortae (100 +/- 11). 17 beta-Estradiol injection of intact males failed to affect aortic progesterone receptor content (93 +/- 17 fmol/mg DNA). However, injection of orchiectomized males with 17 beta-estradiol significantly (P less than 0.05) increased progesterone receptor content to 208 +/- 24 fmol/mg DNA. This value is twice that of intact males and is not significantly different (P greater than 0.05) from the aortic cytoplasmic progesterone receptor content (190 +/- 32 fmol/mg DNA) of 17 beta-estradiol-injected oophorectomized females. These studies establish that intracellular distribution of aortic androgen and estrogen receptors of male or female AXC/SSh rats is regulated by endogenous hormones. The observation that 17 beta-estradiol modulates aortic progesterone receptor content indicates that rat aortic estrogen receptors are physiologically functional. Our data imply that steroid hormones directly regulate aspects of rat cardiovascular cell function and that sexually dimorphic differential regulation may characterize male and female aortic metabolism.

Effect of aging on AXC/SSh rat ventral and dorsolateral prostate S-adenosyl-L-methionine decarboxylase and L-ornithine decarboxylase messenger ribonucleic acid content.

Ventral prostate S-adenosyl-L-methionine decarboxylase (AMDC) and L-ornithine decarboxylase (ODC) transcript content decreased 5-fold as males aged from 6 to 26 months. In contrast, dorsolateral prostate AMDC and ODC transcript content in these individuals was age invariant. The differential effect of aging on tissue transcript levels reflected respective 3.5- and 5-fold decreases in ventral prostate total and poly(A)+ RNA content in aging males, whereas dorsolateral prostate RNA levels essentially were age invariant. Testosterone injection of 26-month-old males increased ventral and dorsolateral prostate content of AMDC and ODC transcripts 4- and 2.5-fold, respectively. Changes in ventral prostate ODC transcript levels correlated well with previously reported age- and testosterone-mediated changes in prostate ODC protein content; however, the relation between ventral or dorsolateral prostate AMDC mRNA levels and previously determined AMDC protein content was less stringent. Our observation that ventral prostate ODC transcript content was 7-fold greater than that of dorsolateral prostate was insufficient to account for the established 200-fold difference in ODC activity in these tissues. Our data imply that transcript content is a principal determinant of ventral prostate ODC activity in aging AXC/SSh rats. However, this relationship does not appear to characterize either ventral or dorsolateral prostate AMDC activity or relative ventral and dorsolateral prostate ODC activity and transcript content. The cause of the age-related preferential loss of ventral prostate RNA remains to be evaluated.

Aging in the AXC/SSh rat: diminished prostate L-ornithine decarboxylase (ODC) activity reflects diminished prostate ODC protein and transcript content.

Immunotitration of L-ornithine decarboxylase (ODC) activity in ventral prostates of young mature (6-month-old) and aged (26-month-old) AXC/SSh rats established that the relation between enzyme activity and prostate ODC mass content was age invariant, demonstrating that the 4-fold diminution in prostate ODC activity in aged subjects represents decreased ODC protein content. Testosterone treatment of aged rats increased prostate ODC activity 2-fold and did not affect prostate ODC half-life. These latter findings and the preceding observation established that the testosterone-mediated increase in prostate ODC activity in aged individuals reflected increased ODC mass content. The half-life of prostate S-adenosyl-L-methionine decarboxylase, another prominent enzyme of polyamine biosynthesis, also was not altered by testosterone treatment of 26-month-old animals. The age-related diminution and testosterone-mediated increase in ventral prostate ODC activity occurred in concert with comparable quantitative changes in ventral prostate ODC transcript content. Because plasma testosterone content was age invariant between 3 and 18 months, the age span during which much of the reduction in prostate ODC activity occurs, and then declined by 50% at 26 months, our studies suggest that age-related diminutions in prostate ODC activity and transcript content reflect altered prostate sensitivity to androgen rather than response to diminished plasma testosterone content. Our data imply that age-related alterations in androgen regulation of androgen-responsive genes may be characteristic of the prostate during aging.

Aging in the AXC rat: diminished prostatic S-adenosyl-L-methionine decarboxylase (AMDC) activity appears to reflect altered expression of the AMDC gene.

We purified AXC rat hepatic S-adenosyl-L-methionine decarboxylase (AMDC) 4900-fold and obtained a preparation that was 75% AMDC. This material caused elaboration of rabbit antirat AMDC antibodies that essentially were monoprecipitating. Antibody from one rabbit was highly effective as an inactivator of prostatic AMDC activity and was used to evaluate the quantitative relationship between antigenic mass and AMDC activity in ventral and dorsolateral prostates of young mature (185-day-old) and aged (776-day-old) AXC rats. Although AMDC activity of aged AXC rat prostates was diminished (ventral, 68%; dorsolateral, 50%), the quantities of antibody required to inactivate 1 U AMDC activity in prostates of young mature and aged rats were identical. This antibody effectively recognized enzymatically inactive AMDC, which is antigenically similar to active AMDC. Therefore, the age-related reductions in prostatic AMDC activity are not due to the production of so-called altered AMDC. Four days of exogenous testosterone treatment of aged AXC rats failed to enhance ventral prostate AMDC activity, whereas AMDC activity in dorsolateral prostates was elevated 2.3-fold. New AMDC activity was antigenically identical to that in dorsolateral prostates of untreated young mature or aged AXC rats. Because we previously established that age-related reductions in AXC rat prostatic AMDC activity are due to neither trivial causes nor enhanced inactivation, our present studies imply that reductions in AMDC activity are due to decreased prostatic AMDC content. These studies are an initial demonstration of senescence-related quantitative reductions in the prostatic content of AMDC molecules, which appear to represent altered expression of a specific androgen-responsive prostatic gene.