Ontogenesis and Sexual Dimorphism of Rat Growth Hormone Messenger Ribonucleic Acid as Studied by in situ Hybridization

Intake of caffeinated, carbonated, or citrus beverage types and development of lower urinary tract symptoms in men and women

Evidence to substantiate recommendations for restriction of caffeinated or acidic beverages as self-management for lower urinary tract symptoms (LUTS) is limited. We examined longitudinal and acute associations between beverage intake and LUTS in the Boston Area Community Health (BACH) cohort (n = 4,144) between 2002 and 2010. Multivariable models tested associations between baseline intakes and progression of LUTS at 5-year follow-up, between follow-up intakes and International Prostate Symptom Scores at follow-up, and between 5-year intake changes and LUTS progression. Greater coffee or total caffeine intake at baseline increased the odds of LUTS progression in men (coffee: >2 cups/day vs. none, odds ratio = 2.09, 95% confidence interval: 1.29, 3.40, P-trend = 0.01; caffeine: P-trend < 0.001), particularly storage symptoms. Women who increased coffee intake by at least 2 servings/day during follow-up (compared with categories of decreased or unchanged intakes) had 64% higher odds of progression of urgency (P = 0.003). Women with recently increased soda intake, particularly caffeinated diet soda, had higher symptom scores, urgency, and LUTS progression. Citrus juice intake was associated with 50% lower odds of LUTS progression in men (P = 0.02). Findings support recommendations to limit caffeinated beverage intake for LUTS, and in men, they suggest benefits of citrus juice consumption. Further clinical research is warranted, particularly of the precise role of sodas containing artificial sweeteners in bladder sensations and urological function.

Modulation of prolactin expression by xenoestrogens

Xenoestrogens are widely used environmental chemicals that have recently been under scrutiny because of their possible role as endocrine disrupters. Among them are endosulfan and chlordane, two persistent insecticides suspected to act as estrogens in living organisms. To test and better understand the potential estrogenic activity of these chemicals, we used a pituitary cell line (GH(3)) known to respond to estrogens by increasing its secretion of prolactin (PRL), a hormone that is well known for its many physiological functions, especially in fetal growth, development, and reproduction. We measured the levels of PRL secretion and PRL mRNA transcription using immunometric tests, Northern blots, and relative quantitative RT-PCR. We also employed the XTT proliferation assay to compare the growth of GH(3) cells stimulated with 17-beta estradiol and endosulfan or chlordane. Our results show that endosulfan and chlordane are able to induce a substantial increase of PRL expression while these two chemicals do not increase cell growth. Together, our results suggest that endosulfan and chlordane could indeed modulate an estrogen-inducible gene such as PRL, possibly acting via second messenger-mediated cellular mechanisms instead of solely competing with estrogens for the nuclear estrogen receptor sites.

Effects of pituitary adenylate cyclase-activating polypeptide (PACAP) on gonadotropin-releasing hormone and somatostatin gene expression in the rat brain

Pituitary adenylate cyclase-activating peptide (PACAP) is a 38-amino acid polypeptide, first isolated from ovine hypothalamus, which directly stimulates the release of several pituitary hormones, including GH, ACTH, and LH. The presence of PACAP receptors in several brain areas, including the hypothalamus, suggests that this peptide might play a role as neurotransmitter/neuromodulator. We have thus investigated the effects of intracerebroventricular (i.c.v.) and intravenous (i.v.) injections of PACAP and the potent PACAP antagonist PACAP(6-38) on gonadotropin-releasing hormone (GnRH) and somatostatin (SS) gene expression in the male rat hypothalamus. The levels of mRNA were measured at the cellular level by quantitative in-situ hybridization. The i.c.v. injection of PACAP produced a 12.5% increase in the GnRH mRNA levels, an effect which was completely prevented by the concomitant administration of the PACAP antagonist. The administration of the PACAP antagonist induced by itself a 12.9% decrease in the hybridization signal. The i.v. administration of the same peptides induced modifications in GnRH gene expression which were completely opposite to those produced by i.c.v. administration. In somatostatinergic neurons located in the periventricular nucleus, the i.c.v. injection of the peptides induced modification in SS gene expression which were very similar to those observed for GnRH gene expression, although the changes were less striking. The i.v. administration of PACAP or its antagonist did not induce any change in the levels of SS mRNA. These results then strongly suggest that PACAP might be involved in a positive regulation of two neuropeptides involved in the control of anterior pituitary secretion via central specific receptors. The inverse influence of PACAP on GnRH gene expression after the i.v. injection might be explained by the short feedback effect induced by the direct stimulation of gonadotropin hormone release following the systemic injection of the peptide.

Expression of growth hormone-responsive serpin mRNAs in perinatal rat liver

Hormonal mechanisms controlling growth of the fetus are poorly understood, and generally growth hormone (GH) is not thought to influence perinatal growth. To examine the influence of GH in the expression of genes in perinatal rat liver, we measured RNA levels of several GH responsive and growth axis genes. Spi 2.1, Spi 2.2, Spi 2.3, insulin-like growth factors (IGF) I and II, and GH receptor mRNAs were measured in rat liver total RNA from gestational days 19, 20, 21, and postnatal day 2. Spi 2.1 and 2.3 genes were faintly expressed on day 20, 6% and 13 +/- 1% of adult levels on gestation day 21, and 6% and 31 +/- 6% of adult levels on day 2. Deoxyribonuclease I (DNase I)-hypersensitive sites in the 5' flanking region of the Spi 2.1 gene, which are concordant with GH response, were not present in DNA extracted from livers at gestation day 19 but were present at days 20, 21, and 2, suggesting the gene is transcriptionally competent after day 19 and that the areas of chromatin vulnerable to DNase I digestion are the same in pre- and postnatal life. Low levels of GH receptor mRNAs (approximately 10% of adult) were present on all measured days. IGF-I mRNA was below quantitatable levels in day 19 or 20 fetal samples and was only 2.7 +/- 0.1% of adult levels on day 21. Levels on day 2 were 9.6 +/- 1.9% of adult. IGF-II mRNA was essentially constant throughout this period, with a minimal increase at day 21 of gestation.(ABSTRACT TRUNCATED AT 250 WORDS)