Search Results
Results 351 - 400 of 860
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Fort F L - - 1995
Lansoprazole is a substituted benzimidazole which inhibits gastric acid secretion by inhibiting the hydrogen-potassium ATPase (proton pump) in the parietal cell. The finding of Leydig cell hyperplasia and Leydig cell tumors in 2-year oral studies in Sprague-Dawley rats but not in CD-1 mice prompted investigative studies to determine the mechanism ...
Bosland M C - - 1995
This study determined the incidence of prostate adenocarcinoma following long-term treatment of NBL and Sprague-Dawley rats with estradiol-17 beta or diethylstilbestrol (DES) plus testosterone and it defined the origin of these tumors. NBL and Sprague-Dawley rats were treated with two Silastic tubing implants (i.d. 1.6 mm, o.d. 3.2 mm) containing ...
Lugg J A - - 1995
Androgens are essential for the expression of normal libido in the male, but their role in the maintenance of the erectile response in humans is controversial. It has been shown previously in the rat that castration induces 1) loss of penile reflexes; and 2) considerable reduction in the erectile response ...
Hirosumi J - - 1995
FK143 is a nonsteroidal new inhibitor of steroid 5 alpha-reductase, an enzyme which converts testosterone into 5 alpha-dihydrotestosterone (DHT). We studied in vivo effects of FK143 on rat and dog prostates. FK143 was orally administered to mature male rats for 14 days. At doses above 1 mg/kg, FK143 significantly reduced ...
Njar V C - - 1995
The crude methanol extract of the stem wood of Quassia amara L. inhibited both the basal and LH-stimulated testosterone secretion of rat Leydig cells in a dose-dependent fashion. Fractionation of the extract by chromatography gave quassin (1) and 2-methoxycanthin-6-one (2); compound 1 proved to be the bioactive agent.
Pienta K J - - 1995
BACKGROUND: Prostate cancer is the most common cancer diagnosed in U.S. men and remains incurable once it has metastasized. Many stages of the metastatic cascade involve cellular interactions mediated by cell surface components, such as carbohydrate-binding proteins, including galactoside-binding lectins (galectins). Modified citrus pectin (pH-modified), a soluble component of plant ...
Ho S M - - 1995
We previously demonstrated that simultaneous treatment of Noble (NBL) rats with estradiol (E2) and testosterone (T) for 16 weeks induces a proliferative response selectively in the dorsolateral prostates (DLP) of all treated animals [1, 2]. The unique sensitivity of rat DLP to the conjoint androgen-estrogen-induced mitogenic action may be attributable ...
Verhoeven G - - 1995
To study the effect of androgens on somatic testicular cells, rats were rendered germ cell depleted by prenatal irradiation (RX). Adult RX rats were treated with a desensitizing dose of a GnRH agonist (GnRHa; Zoladex), combined with an antiandrogen (Nilutamide) to preclude all androgen effects, or combined with testosterone or ...
Berg T - - 1995
The rat kallikrein family consists of multiple closely related proteins. Most of these proteins have been purified from rat submandibular gland (SMG), among them rK9, an enzyme that has a direct vasoconstrictory effect on isolated aortic rings. Recently, two members of the kallikrein family, rK8 and rK9, were also purified ...
Alenfall J - - 1995
Effect of orchiectomy on peripheral benzodiazepine receptors (PBZr) density in hormone sensitive, poorly differentiated Dunning G rat prostatic tumors were studied. A significant increase in PBZr density (1.4-fold) was observed in both mitochondrial fractions (m-fractions) and microsomal fractions (p-fractions) of tumors from orchiectomized rats as compared to tumors from sham ...
Kus L - - 1995
This study examines NMDAR1 receptor subunit mRNA expression and [125I]MK-801 binding in hypothalamic and limbic nuclei of intact, castrate and castrate-dihydrotestosterone propionate (DHTP)-treated male rats. In intact rats, the highest levels of NMDAR1 mRNA were observed in the supraoptic, suprachiasmatic, ventromedial and arcuate nuclei. Low levels of hybridization were observed ...
Pizzichini M - - 1995
Purine nucleotide metabolism was studied in rat liver by following the incorporation of 14C-formate into soluble nucleotides, uric acid and RNA ribonucleotides. After castration, GMP formation was less than that of AMP, and purine nucleotide catabolism and RNA synthesis decreased. Testosterone administration did not modify GMP or AMP synthesis, but ...
Barthold J S - - 1994
Androgens may control rat testicular descent via effects on the genitofemoral nerve or cranial gonadal ligaments. Androgen-mediated release of calcitonin gene-related peptide from the genito-femoral nerve (whose motoneuron cell bodies reside in the sexually dimorphic cremaster nucleus) may stimulate cremaster sac formation and testicular descent. Alternatively, androgens may cause regression ...
Itoh N - - 1994
To investigate the relation between testicular transferrin and insulin-like growth factor-1 (IGF-1) secreted by Sertoli cells and the differentiation of germ cells in the rat, testosterone and/or purified FSH was administered to rats medically hypophysectomized by an LH-RH agonist. Spermatogenesis was quantitatively analyzed and concentrations of intratesticular transferrin and IGF-1 ...
Imamura Y - - 1994
The influence of testosterone treatment on acetohexamide reductase activities in liver microsomes and cytosol of female rats was examined. Acetohexamide reductase activity in liver microsomes was much lower in female rats than in male rats. Combined testosterone treatment in pubertal and adult periods induced male-specific acetohexamide reductase activity in liver ...
Banerjee P P - - 1994
We examined the effects of age and of increasing concentrations of testosterone on the wet weight, protein content, cell number, and cell size of the ventral, dorsal, and lateral lobes of the Brown Norway rat prostate. Young (3 mo of age) and aged (15, 17, and 21 mo of age) ...
Ho S M - - 1994
To date, few studies have been reported on any aspect of DNA damage in organs of intact animals. We and others demonstrated induction of high incidences of dysplasia, a precancerous proliferative lesion, and adenocarcinoma selectively in the dorsolateral prostates (DLPs) of Noble rats exposed to a long-term combined testosterone and ...
Tavares M C - - 1994
Male Wistar rats were injected i.p. with 2 x 10(5) trypomastigotes of the Bolivia strain. Fifteen days later, few parasite nests were observed in the fibromuscular layer surrounding the seminal vesicle acini of chagasic animals and no parasites were detected in the testis and ventral prostate. A significant decrease was ...
Scolnik M D - - 1994
The induction of prostatic lesions in the rat by hormonal manipulation and/or chemical carcinogens in different strains is well documented in literature. However, the selection of a strain for such studies was merely based on the laboratory husbandry facilities rather than on the animal genotype. It is well accepted that ...
Goldstein L A - - 1994
The rat lumbar spinal cord contains a sexually dimorphic motor nucleus, the spinal nucleus of the bulbocavernosus (SNB), whose motoneurons innervate perineal muscles involved in copulatory reflexes. Dendritic development of SNB motoneurons is biphasic and androgen dependent. During the first 4 postnatal weeks, SNB dendrites grow exuberantly, and subsequently retract ...
Scolnik M - - 1994
The vasoactive effect of a fragrance compound, citral, on rat ventral prostate is presented. A combined method of Indian-ink perfusion and postfixation transparency was used. One single dose of citral applied on the back skin of the rat induced an immediate triple response-like effect on the prostatic vascular bed. A ...
Hatier R - - 1994
The aim of the present study was to follow the gamma-GT activity changes in the rat epididymis after withdrawal of androgens. Treatment of adult rats with the LHRH agonist D-Trp 6-LHRH led to reduce serum testosterone concentrations below the limit of detection of the assay. In the treated rats, specific ...
Goh D W - - 1994
Prenatal androgen blockade with the antiandrogen flutamide inhibits the inguinoscrotal phase of testicular descent. The evidence suggests that androgens may act indirectly via the sexually dimorphic genitofemoral nerve (GFN) to control this phase. Rats were exposed to flutamide on gestational days 16 through 19. Seven-day-old rats were subjected to retrograde ...
Yamada K - - 1994
The effects of 2,5-dimethylpyrazine (DMP) on plasma testosterone and levels of polyamines and acid phosphatase in the prostate of rat were studied. A high dose of DMP administered once daily for two weeks to juvenile male rats significantly decreased plasma testosterone and levels of polyamines and acid phosphatase in the ...
Juarranz M G - - 1994
1. The stimulatory effect of VIP on rat prostatic adenylyl cyclase changes during postnatal development. It peaks at 2 months (peripubertal period), remains in a plateau between 3 and 12 months (adult period), and decreases at 24 months (old period). 2. The stimulation of rat prostatic adenylyl cyclase by the ...
Hernandez L - - 1994
Male rats were castrated before puberty. When they were adult, the activity of their mesolimbic dopamine system was tested by ventral striatum microdialysis. Amphetamine injections increased dopamine more in castrated rats than in normal rats. This exaggerated response was attenuated by testosterone replacement therapy. The mechanism by which androgens modulate ...
Kuhnz W - - 1994
The androgenic and the progestational activity of norgestimate (NORG) and levonorgestrel (LNG) were compared in two animal studies. During a Hershberger test in immature castrated male rats and a pregnancy maintenance test in pregnant rats, NORG and LNG were administered subcutaneously at several doses, serum samples were collected from each ...
Winderickx J - - 1994
Cystatin-related protein (CRP), also known as 20 (22)-kDa glycoprotein is expressed not only in the ventral prostate, but also in the lacrimal gland of adult male rats. In this study the expression of CRP in androgen-treated female animals is studied. CRP mRNA is absent in the lacrimal gland of untreated ...
Paul H S - - 1994
Hepatic peroxisome proliferation is induced by a number of agents, including clofibrate. Sustained proliferation of peroxisomes is associated with the development of hepatocellular carcinoma. In the present study, we have investigated the role of testosterone in peroxisome proliferation induced by clofibrate. Three groups of male rats (intact, castrated, and castrated ...
Giuliano F - - 1993
The role of testosterone on peripheral autonomic control of penile erection was studied in rats. Erectile response to cavernous nerve stimulation was measured by intracavernous pressure associated with arterial blood pressure monitoring in anesthetized adult males. Comparison was performed between control (Co), castrated (Ox) and castrated, testosterone-replaced (OxT) rats. Ox ...
Muffly K E - - 1993
Testosterone is the principal hormone necessary for insuring the completion of normal spermatogenesis. However, its precise role in spermatid maturation is not clear. In hypophysectomized rats, testosterone can maintain spermiogenesis if replaced soon after surgery. Delaying treatment results in a reduction in the number of mature spermatids. In culture, testosterone ...
Szot P - - 1993
Previous studies from this and other laboratories have shown that levels of vasopressin (VP) mRNA are reduced in both hypothalamic magnocellular and extrahypothalamic nuclei of the homozygous Brattleboro rat (HOM) when compared to the normal Long-Evans (LE) and heterozygous Brattleboro rats (HET). Since extrahypothalamic VP gene expression is dependent on ...
Pereira O C - - 1993
The development of testes and genital accessory organs, the plasma testosterone concentration and the reactivity of seminal vesicles to catecholamines were studied in rats rendered cryptorchid at the time of prepubertal growth. The wet weights of the accessory organs and the testosterone concentrations were reduced and corresponded to those observed ...
Chieffi-Baccari G - - 1993
The effects of gonadectomy and testosterone treatment on the fine structure of the Harderian gland in male and female green frogs were investigated in different periods of the year. Gonadectomy, carried out when the glands are in the lowest secretory phase (September), causes degenerative changes consisting of a reduction of ...
Gerendai I - - 1993
The possible physiological role of testicular corticotropin-releasing factor (CRF) in the regulation of testicular functions was studied in neonatal rats. Two microlitres of anti-CRF-antiserum (dilution: 1:10 or 1:100) was injected intratesticularly to 5 d-old rats with two testes and to hemicastrates. Five days after hemicastration and treatment of the remaining ...
Murakoshi M - - 1993
Immunohistochemical localization of the cytoskeleton components alpha tubulin and actin in the rat prostate was achieved. Formalin-fixed paraffin sections were prepared and examined by the avidin-biotin-peroxidase-complex method (ABC method). We observed that the cytoplasm of the glandular epithelial cells were stained by alpha tubulin and actin antibodies. The staining intensity ...
Mundle S D - - 1993
In vivo administration of HSPI (10.7 kDa FSH suppressing peptide of prostate) to intact adult male rats was found to suppress the basal levels of incorporation of 3H-thymidine into DNA of ventral and dorsolateral lobes of the prostate, in a dose-dependent manner. Interestingly, microscopic examination of the prostate histology of ...
Costello L C - - 1993
A major and unique function of the prostate is the production of extremely high levels of citrate. Testosterone is an important regulator of this function. This regulation is achieved by hormonal stimulation of citrate synthesis by prostate secretory epithelial cells. Previous studies have established that testosterone stimulates the mitochondrial transamination ...
Roof R L - - 1993
In a morphological examination of the hippocampal formation of pre-pubescent rats, a testosterone-related sexual dimorphism was observed. The dentate gyrus granule cell layer was greater (8-9%) in width and length and laterally asymmetrical in males and in testosterone-treated females. This dimorphism was previously observed in adult rats. These data demonstrate ...
Hayashi N - - 1993
Adult rodent (rat and mouse) prostatic ducts (PR) were recombined heterospecifically with fetal urogenital sinus mesenchyme (UGM) (mouse UGM plus rat PR or rat UGM plus mouse PR), and the resultant tissue recombinants were grafted under the renal capsule of male athymic mice. For recombination with mouse UGM the ductal ...
Yazawa H - - 1993
Muscarinic cholinoceptor subtypes in the rat prostatic membrane were characterized by using [3H]-methyl-quinuclidinyl benzilate (QNB) in ligand binding studies. [3H]-Methyl-QNB saturation experiments showed the existence of a homogeneous population of binding sites with a high affinity (KD value) of 0.24 +/- 0.04 nM and a maximum binding site number (Bmax) ...
Foresta C - - 1993
The aim of this study was to clarify whether calcium ions play a role in the mechanisms by which rat atriopeptin II exerts its stimulatory effects on rat Leydig cell steroidogenesis. The absence of calcium in the medium and the calcium channel-blocker drug, verapamil, both significantly inhibited testosterone production in ...
Weisman Y - - 1993
We have found previously that rat diaphyseal bone in vivo, as well as rat embryo calvaria cells in culture, show a sex-specific response to gonadal steroids in stimulation of creatine kinase (CK)-specific activity, and the rate of [3H]thymidine incorporation into DNA; male-derived cells responded only to testosterone or to dihydrotestosterone ...
Bluthé R M - - 1993
To assess the role of the vomeronasal organ (VNO) in the dependence of social recognition on vasopressinergic transmission, vomerectomized rats were compared to intact and castrated male rats. Removal of the VNO significantly decreased the duration of social investigation and temporarily impaired social recognition. In contrast to sham-operated animals and ...
Ho S M - - 1993
We demonstrated previously that simultaneous treatment of intact Noble (NBL) rats with testosterone and estradiol-17 beta (E2) for 16 weeks consistently induced a putative precancerous lesion, termed dysplasia, in the dorsolateral prostate (DLP) of all animals. Since treatment of rats with androgen alone did not elicit the same response, we ...
Pirog E C - - 1993
UDP-glucuronyl transferase (UDPGT) activity was determined for androgens in tissue minces and microsomal fractions from the liver and extrahepatic tissues (kidney, skin, prostate, and preputial glands) of the male rat. Liver microsomes showed the highest UDPGT activity with each of the androgens tested (Vmax = 7, 3, and 10 nmol/minute/mg ...
Hwu C M - - 1993
The effects of orchiectomy and testosterone replacement on the plasma concentration and the atrial stores of atrial natriuretic peptide (ANP) were studied in the rats. Male rats were orchiectomized (Orc) three weeks before replacement with testosterone propionate (TP, 20 mg/ml/kg body weight) or sesame oil for five days. Immunoreactive ANP ...
Maggi R - - 1993
Recent evidence supports the hypothesis of a direct action of LHRH at the level of the prostate. Since peptidases able to degrade the hormone are present in several LHRH target structures, it was deemed of interest to investigate whether the prostate of adult normal male rats might possess LHRH degrading ...
Prins G S - - 1993
Autoregulation of androgen receptors (AR) in the rat prostate gland has previously been shown to be lobe specific. Saturation ligand-binding assays revealed that AR fell to very low levels in the ventral and dorsal prostate within 7 days after castration, whereas lateral lobe AR were present at intact levels at ...
Sharma O P - - 1992
This study examined the effects of diet on the development of prostatitis in male rats. Adult male rats were placed on either of two specially formulated diets which differed from one another by the presence or absence of soy as the protein source. A third group of rats (control) was ...
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