Impact of sex, androgens, and prostate size on C57BL/6J mouse urinary physiology: functional assessment

Laboratory mice are used to identify causes of urinary dysfunction including prostate-related mechanisms of lower urinary tract symptoms. Effective use of mice for this purpose requires a clear understanding of molecular, cellular, anatomic, and endocrine contributions to voiding function. Whether the prostate influences baseline voiding function has not been specifically evaluated, in part because most methods that alter prostate mass also change circulating testosterone concentrations. We performed void spot assay and cystometry to establish a multiparameter “baseline” of voiding function in intact male and female 9-wk-old (adult) C57BL/6J mice. We then compared voiding function in intact male mice to that of castrated male mice, male (and female) mice treated with the steroid 5α-reductase inhibitor finasteride, or male mice harboring alleles ( Pbsn4cre/+; R26RDta/+) that significantly reduce prostate lobe mass by depleting prostatic luminal epithelial cells. We evaluated aging-related changes in male urinary voiding. We also treated intact male, castrate male, and female mice with exogenous testosterone to determine the influence of androgen on voiding function. The three methods used to reduce prostate mass (castration, finasteride, and Pbsn4cre/+; R26RDta/+) changed voiding function from baseline but in a nonuniform manner. Castration feminized some aspects of male urinary physiology (making them more like intact female mice) while exogenous testosterone masculinized some aspects of female urinary physiology (making them more like intact male mice). Our results provide evidence that circulating testosterone is responsible in part for baseline sex differences in C57BL/6J mouse voiding function while prostate lobe mass in young, healthy adult mice has a lesser influence.

Factors Driving Unique Urination Phenotypes of Male and Female 9-week-old C57BL/6J Mice

ABSTRACTLaboratory mice are used to identify causes of urinary dysfunction including prostate-related mechanisms of Lower Urinary Tract Symptoms (LUTS). Effective use of mice for this purpose requires a clear understanding of molecular, cellular, anatomical, and endocrine contributions to voiding function. Whether the prostate influences baseline voiding function has not been specifically evaluated, in part because most methods that alter prostate mass also change circulating testosterone concentrations. We performed void spot assay and cystometry to establish a multi-parameter “baseline” of voiding function in intact male and female 9-week-old (adult) C57BL/6J mice. We then compared voiding function in intact male mice to that of castrate males, males (and females) treated with the steroid five alpha reductase inhibitor finasteride, or males harboring alleles (Pbsn4cre/+;R26RDta/+) that significantly reduce prostate lobe mass by depleting prostatic luminal epithelial cells. We evaluated aging-related changes in male urinary voiding. We also treated intact male, castrate male, and female mice with exogenous testosterone to determine the influence of androgen on voiding function. The three methods used to reduce prostate mass (castration, finasteride, Pbsn4cre/+; R26RDta/+) changed voiding function from baseline but in a nonuniform manner. Castration feminized some aspects of male urinary physiology (making them more like intact female) while exogenous testosterone masculinized some aspects of female urinary physiology (making them more like intact male). Our results provide evidence that circulating testosterone is responsible in part for baseline sex differences in C57BL/6J mouse voiding function while prostate lobe mass in young, healthy adult mice has a lesser influence.

EFFECT OF REPLACING RICE BRAN OR FISH MEAL BY FRESH OR DRIED MULBERRY LEAVES ON DIGESTIBILITY AND NITROGEN RETENTION OF PIGS

Two experiments were conducted to study the effect of replacing rice bran or fishmeal by fresh or dried mulberry leaves on digestibility and nitrogen retention of pigs. Inexperiment 1, a double 4x4 Latin square design in a 2x4 factorial arrangement was used tostudy the effect of graded levels of mulberry leaf meal (0, 15, 30 and 50% on a dry basis,respectively) in diets based on rice brans and broken rice on the N balance of eight youngcastrate male Mong Cai pigs with a mean weight of 15 kg. Mulberry leaf meal (MLM)contained DM 30.4% and in the dry matter: ash 16.9, crude fibre 20.1 and crude protein(Nx6.25) 25.4%, respectively. Feed intake was calculated to be 50 g DM/kg body weight.Although not significant, DM and organic matter digestibility appeared to increase withincreasing levels of dietary MLM. Organic matter digestibility was significantly better(P<0.05); N balance indices improved with the inclusion of MLM in the diet, and this effectwas significant for N retention (P<0.05) when expressed as proportion of the digested N. Inexperiment 2, six Large White castrate male pigs, weighing on average 15 kg, wereallocated according to a balanced change-over design, to two diets where mulberry leaves,either in milled of sun-dried or chopped off fresh, contributed about 45% of the total dailyN intake in iso-nitrogenous diets (Nx6.25, 13.7% on a dry basis). There were no significanteffects of treatment on DM, organic matter and N digestibility but dry leaves wereassociated with slightly lower digestibility values. N balance tended to be better in pigs fedwith fresh mulberry leaves compared to mulberry leaf meal. It can be concluded that inrice-based diets, it is possible to use mulberry leaves as the main protein source.Keywords: Digestibility, leaves, mulberry, pigs, protein.

VT-464: A novel, selective inhibitor of P450c17(CYP17)-17,20 lyase for castration-refractory prostate cancer (CRPC).

e15167 Background: CYP17 is a single protein with two distinct enzyme activities, 17 α-hydroxylase (hydroxylase) and 17,20-lyase (lyase). Reduction of extra-gonadal androgen production through CYP17 inhibition is a validated CRPC treatment paradigm. While treatment with the recently-approved CYP17 inhibitor, abiraterone acetate (AA), increases overall survival in post-docetaxel CRPC patients (de Bono et al, N Engl J Med 2011; 364:1995-2005), it is also associated with cortisol (F) suppression and increased steroid concentrations up-stream of CYP17 hydroxylase. The clinical candidate VT-464 is an oral, non-steroidal, lyase-selective CYP17 inhibitor. The study objectives were to compare VT-464 to abiraterone in regards to in vitro selectivity and to compare VT-464 to AA in regards to in vivo primate endocrine response. Methods: Human CYP17 hydroxylase and lyase IC50 values were determined for VT-464 and abiraterone in vitro. Plasma progesterone (P), F, and testosterone (T) responses were measured 0-24 hours after single subcutaneous doses of AA (12.5 mg/kg), VT-464 (6.25 and 12.5 mg/kg), or vehicle in adult, castrate, male rhesus monkeys. Results: Human lyase and hydroxylase IC50 values were 69nM and 670nM for VT-464 and 15nM and 2.5nM for abiraterone, respectively. AA and both dose levels of VT-464 produced a similar overall reduction in plasma T, compared to vehicle (p ≤ 0.009). AA treatment resulted in an elevated plasma P (peak increase >9,000%; p ≤ 0.05), compared to both VT-464 treatments and vehicle. F was not affected by either VT-464 dose, whereas AA resulted in F suppression (p ≤ 0.005) compared to vehicle. Conclusions: VT-464 was 10-fold more selective for human CYP17 lyase vs. hydroxylase inhibition. This selectivity was associated with androgen suppression, but not increases of up-stream steroids or F suppression in male monkeys. In contrast, abiraterone was 6-fold more selective for hydroxylase vs. lyase inhibition resulting in associations with increased up-stream steroids and F suppression in AA-treated male monkeys, consistent with clinical observations in CRPC. VT-464 may thus provide a more lyase-selective alternative to AA for extra-gonadal androgen suppression in CRPC.

VT-464: A novel, selective inhibitor of P450c17(CYP17)-17,20 lyase for castration-refractory prostate cancer (CRPC).

198 Background: CYP17 is a single protein with two distinct enzyme activities, 17 α-hydroxylase (hydroxylase) and 17,20-lyase (lyase). Reduction of extragonadal androgen production through CYP17 inhibition is a validated CRPC treatment paradigm. While treatment with the recently-approved CYP17 inhibitor, abiraterone acetate (AA), increases overall survival in post-docetaxel CRPC patients (de Bono et al, N Engl J Med 2011; 364:1995–2005), it is also associated with cortisol (F) suppression and increased steroid concentrations up-stream of CYP17 hydroxylase. The clinical candidate VT-464 is an oral, non-steroidal, lyase-selective CYP17 inhibitor. The study objectives were to compare VT-464 to abiraterone in regards to in vitro selectivity and to compare VT-464 to AA in regards to in vivo primate endocrine response. Methods: Human CYP17 hydroxylase and lyase IC50 values were determined for VT-464 and abiraterone in vitro. Plasma progesterone (P), F, and testosterone (T) responses were measured 0-24 hours after single subcutaneous doses of AA (12.5 mg/kg), VT-464 (6.25 and 12.5 mg/kg), or vehicle in adult, castrate, male rhesus monkeys. Results: Human lyase and hydroxylase IC50 values were 69nM and 670nM for VT-464 and 15nM and 2.5nM for abiraterone, respectively. AA and both dose levels of VT-464 produced a similar overall reduction in plasma T, compared to vehicle (p ≤ 0.009). AA treatment resulted in an elevated plasma P (peak increase >9,000%; p ≤ 0.05), compared to both VT-464 treatments and vehicle. F was not affected by either VT-464 dose, whereas AA resulted in F suppression (p ≤ 0.005) compared to vehicle. Conclusions: VT-464 was 10-fold more selective for human CYP17 lyase vs. hydroxylase inhibition. This selectivity was associated with androgen suppression, but not increases of up-stream steroids or F suppression in male monkeys. In contrast, abiraterone was 6-fold more selective for hydroxylase vs. lyase inhibition resulting in associations with increased up-stream steroids and F suppression in AA-treated male monkeys, consistent with clinical observations in CRPC. VT-464 may thus provide a more lyase-selective alternative to AA for extra-gonadal androgen suppression in CRPC.

Epicardial fat gene expression after aerobic exercise training in pigs with coronary atherosclerosis: relationship to visceral and subcutaneous fat

Epicardial adipose tissue (EAT) is contiguous with coronary arteries and myocardium and potentially may play a role in coronary atherosclerosis (CAD). Exercise is known to improve cardiovascular disease risk factors. The purpose of this study was to investigate the effect of aerobic exercise training on the expression of 18 genes, measured by RT-PCR and selected for their role in chronic inflammation, oxidative stress, and adipocyte metabolism, in peri-coronary epicardial (cEAT), peri-myocardial epicardial (mEAT), visceral abdominal (VAT), and subcutaneous (SAT) adipose tissues from a castrate male pig model of familial hypercholesterolemia with CAD. We tested the hypothesis that aerobic exercise training for 16 wk would reduce the inflammatory profile of mRNAs in both components of EAT and VAT but would have little effect on SAT. Exercise increased mEAT and total heart weights. EAT and heart weights were directly correlated. Compared with sedentary pigs matched for body weight to exercised animals, aerobic exercise training reduced the inflammatory response in mEAT but not cEAT, had no effect on inflammatory genes but preferentially decreased expression of adiponectin and other adipocyte-specific genes in VAT, and had no effect in SAT except that IL-6 mRNA went down and VEGFa mRNA went up. We conclude that 1) EAT is not homogeneous in its inflammatory response to aerobic exercise training, 2) cEAT around CAD remains proinflammatory after chronic exercise, 3) cEAT and VAT share similar inflammatory expression profiles but different metabolic mRNA responses to exercise, and 4) gene expression in SAT cannot be extrapolated to VAT and heart adipose tissues in exercise intervention studies.