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PubMed1989

Activation of sexual behavior by implantation of testosterone propionate and estradiol benzoate into the preoptic area of the male Japanese quail (Coturnix japonica).

Intracranial implantation of minute pellets of gonadal steroids was performed to determine neuroanatomical loci at which steroids activate sexual behavior in the Japanese quail (Coturnix japonica). In this species, systemic treatment of castrated males with either testosterone propionate (TP) or estradiol benzoate (EB) restores male-typical copulatory behavior (head grabbing, mounting, and cloacal contact movements). In addition, EB activates female-typical receptive behavior (crouching). Adult male castrated quail were implanted intracranially with 300-micrograms pellets containing TP, EB, or cholesterol (CHOL) and behavior was tested with intact males and females. Either TP or EB pellets in the preoptic area (POA) activated male-typical copulatory behavior. Mounting was specifically activated without concomitant activation of other steroid-sensitive sexual and courtship behaviors. TP and EB implants in adjacent nuclei containing receptors for these steroids and CHOL implants in POA had no effect on male-typical copulatory behavior. Eighteen percent of all males tested for female-typical receptivity crouched, but no specific effect of EB was seen at any site. The similarity of the POA sites for activation of mounting by TP and EB is consistent with the hypothesis that cells within the POA aromatize testosterone to estrogens, which directly stimulate the cellular processes leading to behavioral activation.

Animals↗
PubMed1990

Blockade of lordosis by androst-1,4,6-triene-3,17-dione (ATD) and tamoxifen in female hamsters primed with testosterone propionate.

Normal female hamsters display lordosis after testosterone propionate (TP) plus progesterone (P) treatments. Such effect is probably mediated through aromatization of testosterone (T) into estradiol. If so, then an aromatase inhibitor (ATD) or an estrogen antagonist (tamoxifen, TAM) should be able to block the activational effect of T on lordosis. To test this hypothesis, 48 ovariectomized female hamsters were assigned into six groups which, according to treatments received, were ATD + TP, TAM + TP, OIL + TP, ATD + EB (estradiol benzoate), TAM + EB, and OIL + EB groups. The groups received assigned treatments for 2 days and were injected with P on the third day. Five minutes of behavior test was conducted 4 hr after P injection. The OIL + TP, OIL + EB, and ATD + EB groups all had averaged total lordosis duration (TLD) longer than 200 sec. The TLD of the TAM + EB group was only 117 sec. The ATD + TP and TAM + TP groups showed almost no lordosis. The results showed that the estrogen antagonist (TAM) impaired lordosis no matter whether the animals were primed with TP or EB, but the aromatase inhibitor (ATD) blocked lordosis only in TP primed females. It is concluded that the aromatization of T to estrogen is required for testosterone activation of lordosis in female hamsters.

Androstatrienes↗
PubMed1985

Determination of 2-(4-isobutylphenyl)propionic acid in bulk drug and compressed tablets by reversed-phase high-performance liquid chromatography.

A reversed-phase liquid chromatographic method was developed for 2-(4-isobutylphenyl)propionic acid (IBPP) in bulk drug and compressed tablets containing 100-600 mg of drug per tablet. The chromatographic system consists of a microparticulate octadecylsilica column and a mobile phase of aqueous acetonitrile buffered with chloroacetic acid. Whole tablets are disintegrated, and the IBPP dissolved in a solution of the internal standard in mobile phase. The resulting suspension is then centrifuged, and an aliquot of the supernatant chromatographed. This system separates IBPP from its analogues and degradation products in less than 10 min. Recovery of the drug from spiked placebo preparations was quantitative. Precision of the assay was 0.3 and 0.7%, relative standard deviation, for bulk drug and Motrin tablets, respectively.

Chemical Phenomena↗
PubMed1988

Direct determination of molecular ratios of peptides coupled via N-succinimidyl 3-(2-pyridyldithio)propionate to carrier proteins using high performance liquid chromatography.

A simple, rapid and reproducible method is presented for direct determination of the substitution ratio of a carrier protein with a synthetic nonradioactively labeled peptide. The peptide was covalently linked by a thiol group of a cysteine residue to the immunogenic carrier protein using the heterobifunctional reagent N-succinimidyl 3-(2-pyridyldithio)propionate. The substitution ratio was determined after reductive cleavage of the intermolecular disulfide bond between peptide and carrier and the amount of carrier and peptide quantitated directly by calibrated HPLC analysis within 15 min.

Animals↗
PubMed1985

A new inhibitor of the long-chain fatty acid transfer across the mitochondrial membrane: 2-(3-methylcinnamylhydrazono)-propionate (BM 42.304).

Using two different assay systems to distinguish between overt and inner forms of carnitine palmitoyl transferase (CPT, EC 2.3.1.21) of intact guinea-pig liver mitochondria, we have shown that the hypoglycemic agent 2-(3-methylcinnamylhydrazono)-propionate (BM 42.304) inhibits the activity of carnitine-acylcarnitine translocase of liver mitochondria. The results offer an explanation for the inhibitory effect of the compound on ketogenesis with oleate but not with octanoate in the perfused guinea-pig liver, previously reported by us (Biochem. Pharmacol. 32, 3405-3412, 1983).

Acyltransferases↗
PubMed1995

Effects of nandrolone propionate on experimental tumor growth and cancer cachexia.

We studied the tumor host response to excessive doses of an anabolic steroid (nandrolone propionate, 2.5 mg 20 g intraperitoneally every second day for 11 days) with respect to body composition and tumor cell kinetics in MCG 101 sarcoma-bearing mice (C57BL/6J) with progressive cachexia. Although survival and food intake were not affected, a significant weight gain was observed that was essentially attributed to water retention. Net protein content was increased only to a minor extent (15%), of which only the liver accounted for a significant part of the body compartments. Hepatic protein accumulation was obviously caused by decreased protein degradation, since hepatic RNA content was unchanged. After anabolic steroid administration, reduced histochemical staining of succinate dehydrogenase was observed in skeletal muscles rich in oxidative type 1 fibers, but it was not different from that of tumor-bearing control animals, which was also confirmed by measurements of citrate synthase and cytochrome c oxidase activities in skeletal muscle and liver tissue. The anabolic steroid had no significant effect on tumor growth in terms of weight progression, energy state, polyamine synthesis rate, cell division rate, and cell cycle cytocompartments. We conclude that anabolic steroid supplementation is not therapeutically beneficial in counteracting progressive weight loss in experimental cancer.

Anabolic Agents↗
PubMed1975

Lordosis behavior and mounting behavior in male rats: effects of castration and treatment with estradiol benzoate or testosterone propionate.

Male rats were selected for showing or not showing lordosis in response to manual stimulation. They were subsequently tested for mounting behavior with receptive females and for lordosis behavior in response to manual stimulation and to male mounting. Males showing lordosis as intacts displayed this behavior more readily following castration or castration and treatment with estradiol benzoate or testosterone propionate than males which did not show lordosis before castration. No group differences in mounting behavior could be detected under any of the endocrine conditions studied. It is suggested that the neural mechanisms mediated mounting and lordosis are dissociated and that individual differences in the occurrence of lordosis in male rats are due to differences in neural sensitivity to estrogen.

Animals↗
PubMed1987

Effects of prenatal testosterone propionate treatment on saccharin preference of adult rats exposed to ethanol in utero.

Prenatal exposure to alcohol feminizes saccharin consumption patterns in adult male rats. To study the involvement of testosterone in this effect, testosterone propionate (TP) was administered to pregnant dams in an attempt to reverse that feminized saccharin consumption pattern in the male offspring. Female offspring were also studied to determine the effect of TP on saccharin preference in normal males and females. During the last week of gestation, dams were administered a liquid diet containing 35% ethanol derived calories, an isocaloric liquid diet containing no ethanol, or Purina Lab Chow. Half of the dams in each group received twice daily injections of TP, the other half were injected with the oil vehicle. Saccharin consumption of adult fetal alcohol exposed (FAE) males from dams administered oil or TP was significantly greater than controls, indicating that the feminized pattern of saccharin consumption of FAE males cannot be overcome with TP administration during the prenatal period. In controls, prenatal TP exposure alone was found to increase adult saccharin consumption in both sexes. Prenatal administration of TP was also found to markedly depress body weight of offspring of dams receiving the liquid diets compared to offspring from dams receiving the same diets plus oil injections. Body weights of offspring from TP or oil injected dams receiving the chow fed diets during pregnancy did not differ.

Animals↗
PubMed1988

Sexual interactions between estrous female rats and castrated male rats treated with testosterone propionate or estradiol benzoate.

Estrous female rats display 'precopulatory behaviors' such as ear wiggling and hopping/darting when castrated males treated with testosterone propionate (TP) are placed in their vicinity and before copulatory interactions have taken place. Castrated males treated with estradiol benzoate (EB) do not elicit these precopulatory behaviors in advance of copulatory interactions. It therefore seemed of interest to study females' sexual behavior with castrated males treated with TP or EB when males or females had primary control over the temporal patterning of the behavior. Unrestrained sexual behavior (= male control) with EB-treated males was characterized by large numbers of intromissions and long periods of time preceding ejaculation, as compared with interactions with TP-treated males. The temporal pattern of sexual behavior did not change importantly when the males were tethered (= sexual behavior controlled by females). When given a choice between two sexually active castrated and tethered males, one treated with TP and the other with EB, estrous females 'preferred' EB-treated animals in various respects. Fewer interactions occurred with, and less time was spent in the vicinity of, TP-treated males over prolonged observation periods (115-135 min). The preference for EB-treated males disappeared, and TP- and EB-treated animals became equally attractive, when the vaginal opening of the female animals was covered with adhesive tape to prevent the occurrence of penile intromissions during mounting. It is concluded that female control over copulatory behavior does not necessarily change the females' sexual behavior.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

High dosage testosterone propionate induces copulatory behavior in the obese male Zucker rat.

Genetically obese male Zucker rats sire few litters compared with lean males. High dosage testosterone propionate (TP) dramatically improves their litter production. Here we report the effect of high dosage TP on the copulatory behavior of obese males. Subjects were placed with ovariectomized, hormonally-primed females 24 hr after receiving a subcutaneous injection of vehicle or 20 mg TP. Other obese males received three consecutive daily TP injections or TP once every three days for up to 30 days prior to being tested. While 90% of sham-injected lean males became sexually active, only 18.2% of sham-injected obese males did so. In contrast 50% to 62.5% of TP-injected obese males became active depending on TP exposure. The proportion of obese males which ejaculated was high for sham-injected males which copulated, but varied with TP exposure for TP-injected males. In other respects the copulatory performance of obese and lean males was similar. High dosage TP increases fertility by correcting a behavioral deficit. Three possible mechanisms of TP action are proposed.

Animals↗
PubMed1979

Effects of various doses of testosterone propionate on intratesticular and plasma testosterone levels and maintenance of spermatogenesis in adult hypophysectomized rats.

Adult hypophysectomized rats were maintained on different regimens of testosterone propionate (TP) treatment for 27 days (0.2, 0.4, 0.6 and 1 mg/day) and autopsied 16 hours after the last injection. Blood samples were taken, sex organs were weighed and one testis from each animal was fixed in Bouins fluid for histologic analysis. The other testis and blood were used for testosterone (T) determinations. Both testicular and plasma T were below detectable levels in hypophysectomized control rats. The plasma T level showed a dose response relationship with increasing dose of TP but such was not the case for intratesticular T concentrations. Qualitative and quantitative evaluation of testis sections showed that spermatogenesis was incomplete in rats receiving 0.2 mg TP/day characterized by the absence of step 15 to 19 spermatids, degeneration of some pachytene spermatocytes and a significantly lower yield of B type spermatogonia. Analysis of testis sections from animals treated with 0.4 to 1 mg TP/day showed complete maintenance and maturation of pachytene spermatocytes, meiosis and spermiogenesis. However, even with the highest dose of TP (1 mg/day) the total yield of B type spermatogonia was only about 58% of the intact controls. It is concluded that at least 0.4 mg/day of exogenous TP is essential for qualitative maintenance of spermatogenesis in hypophysectomized rats with an intratesticular T concentration of 17 to 18 ng/gm testis.

Animals↗
PubMed1994

Binding kinetics of fluticasone propionate to the human glucocorticoid receptor.

Receptor-ligand interactions of fluticasone propionate (FP), a glucocorticoid used for inhalation therapy, were determined and compared with dexamethasone, budesonide, and beclomethasone-17-monopropionate, the active metabolite of beclomethasone dipropionate. Two approaches, evaluation of binding kinetics and competition assays, were applied to obtain relative receptor affinities (RRAs) with dexamethasone as reference. A higher association rate constant and a distinctly lower dissociation rate constant for FP compared with the other glucocorticoids resulted in an equilibrium dissociation constant (Kd) of 0.49 nmol/l. Kd dexamethasone was 9.36 nmol/l; derived RRA of FP was 1910. The calculated half-time of the FP-receptor complex was 10 h, thus exceeding the half-times of all other glucocorticoids as well as their RRAs. Competition assays clearly confirmed the rank order of the tested glucocorticoids, although RRAs were generally lower than those found in kinetic assays and strongly dependent on the assay conditions. The high receptor affinity of FP is reflected by clinical trials demonstrating its superiority to other glucocorticoids. For therapeutic application, the long half-time of the FP-receptor complex should support the practicality of longer dose-intervals.

Administration, Topical↗
PubMed1991

The effect of short term feeding of the antioxidant triethyleneglycol-bis-3(3-tert-butyl-4-hydroxy-5-methyl)propionate on serum thyrotropin and thyroid hormones in the male rat.

Male rats were fed triethyleneglycol-bis-3(3-tert-butyl-4-hydroxy-5-methyl)propionate (TK 12627) admixed with the food at a concentration of 1000 ppm for 3, 6, 13, and 20 days. Treatment resulted in time-dependent and marked increases in serum levels of thyrotropin (TSH) and reverse triiodothyronine (rT3). Serum levels of thyroxine (T4) were slightly and transiently decreased, whereas triiodothyronine (T3) levels decreased by 35-50% at all time periods. Treatment with 50, 150, 500, and 1000 ppm for 2 weeks resulted in dose-related increases in thyroid and liver weights, follicular hypertrophy of the thyroid, morphological changes of the pituitaries, liver hypertrophy, and similar changes in the serum parameters described above. At 50 ppm, no alterations in the weights and morphology of the liver, thyroid, or pituitary nor in the serum levels of TSH or T4 were observed. The effects of TK 12627 observed at a dose of 1000 ppm for 2 weeks were reversible after cessation of treatment. Decreases in T3, increases in rT3, and no change in T4 serum levels were also obtained when thyroidectomized T4-substituted rats were treated with 1000 ppm TK 12627 for 28 days, indicating that the effects of TK 12627 are probably due to inhibition of the 5' monodeiodination of T4 to T3 and rT3 to diiodothyronine with compensatory increases in thyroid hormone conjugation at extrathyroidal sites.

Animals↗
PubMed1996

New developments in the molecular pharmacology of alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate and kainate receptors.

Separation of non-N-methyl-D-aspartate subtypes of glutamate receptors, known as alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) and kainate receptors, is traced through conventional pharmacology to molecular biology. The physiology and pharmacology of recombinant receptor subtypes (GluR1-7 and KA1-2) are described. Competitive antagonists, e.g., the quinoxalinedione, 2,3-dihyroxy-6-nitro-7-sulphamoyl-benz(F)quinoxaline, and the decahydroisoquinoline, 3S,4aR,6R, 8aR-6-[2-(1(2)H-tetrazol-5-yl)ethyl]-decahydroisoquinolin e-3-carboxylate, have a broad antagonist spectrum, except that the latter is inactive on GluR6. The 2,3-benzodiazepines noncompetitively antagonise the AMPA receptor GluR1-4. Desensitisation of AMPA (GluR1-4) and kainate (GluR5-7 and KA1-2) receptors is blocked by cyclothiazide and concanavalin A, respectively. Polyamine toxins block AMPA receptors not containing GluR2 and unedited kainate receptors (GluR5-6). These data correlate well with results on native neurons characterised by techniques such as in situ hybridisation.

Allosteric Regulation↗
PubMed1981

Enhancement of the immunogenicity of the maize rough dwarf virus outer shell with the cross-linking reagent dithiobis(succinimidyl)propionate.

Injection into rabbits of native or glutaraldehyde (GA)-treated intact particles of the fijivirus maize rough dwarf virus (MRDV) failed to yield antibodies to the outer shell of the virus. After fixation of the particles with the cross-linking reagent dithiobis(succinimidyl)propionate (DSP), antisera were obtained reacting with the outer shell of MRDV (both DSP-fixed and unfixed) to a titre of 1/1024 in immunoelectron microscopic decoration tests, but giving no reaction with another fijivirus, oat sterile dwarf virus, whose subviral particles are known to be unrelated to those of MRDV. Further fixation of the DSP-fixed particles with GA did not appear to enhance immunogenicity. Stabilization with DSP could have further application with viruses the instability of which renders them poor immunogens.

Animals↗
PubMed1984

Affinity labelling of 5-aminolevulinic acid dehydratase with 2-bromo-3-(5-imidazolyl)propionic acid.

2-Bromo-3-(5-imidazolyl)propionic acid, a zinc-directed thiol reagent, inactivates the enzyme 5-aminolevulinic acid dehydratase from bovine liver (5-aminolevulinate hydro-lyase (adding 5-aminolevulinate and cyclizing, EC 4.2.1.24). The substrate, 5-aminolevulinic acid, completely protects against inactivation. The reagent inhibits the zinc-containing enzyme to a greater extent than the zinc-deprived enzyme; and it competes with the zinc chelator 1,10-phenanthroline. The reagent alkylates essential sulfhydryl groups of the enzyme, since the extent of the inactivation depends on the reduction of the enzyme protein by thiol compounds. It is concluded that the zinc site, the substrate site and the essential sulfhydryl groups are in close proximity in the active site.

Affinity Labels↗
PubMed1992

Stability properties of Aplysia oxymyoglobin: effect of esterification of the heme propionates.

When compared with sperm whale MbO2 as a reference Aplysia MbO2 is extremely susceptible to autoxidation, and its pH dependence for the reaction is also unusual. Kinetic and thermodynamic analyses have shown that two types of carboxyl group with pKa = 4.3 and 6.1 at 25 degrees C are involved in the stability property of Aplysia MbO2, the protonation of these groups being responsible for an increase in its autoxidation rate in the acidic pH range. Since protoheme has two carboxyl groups of the propionic acid side-chains, we have prepared Aplysia myoglobin containing the dimethylester of protohemin. The autoxidation of this derivative was found to be described by the involvement of only one type of carboxyl group with pKa = 4.4. A possible candidate for the protein residue was therefore discussed on the basis of the known amino acid sequences of three Aplysia myoglobins: it is suggested that Glu-94, next to the proximal His-95, is the most likely candidate.

Amino Acid Sequence↗
PubMed1983

Effects of 5-fluorouracil and 2 alpha-methyldihydrotestosterone propionate on the growth of human breast carcinoma MCF-7 in vitro.

5-Fluorouracil (5-FU) and 2 alpha-methyldihydrotestosterone propionate (MDTP) have effectively induced complete regressions of induced rat mammary carcinomas; in combination, regressions were additive and synergistic. Present aims were to determine whether similar antitumor effects were obtainable with a human mammary carcinoma, MCF-7, and to affirm the synergism of 5-FU and MDTP. After incubation in vitro for 3 days and exposure to drug for another 2 days, cell counts and/or determinations of total cell protein revealed growth inhibitions of 16-87% by 5-FU at 130-1300 micrograms/ml and 16-94% by MDTP at 0.36-360.5 micrograms/ml. Combinations of 5-FU and MDTP at the same inhibitory doses (ID) yielded approximately additive growth inhibitions. Algebraic and geometric (isobole) methods of analyses showed that these inhibitions were additive or synergistic, depending on the iso-effective dose used. Precursor incorporation into macromolecules also showed approximately additive effects for MCF-7 cells treated with 5-FU and MDTP, each at ID15. These data demonstrate significant additive growth-inhibitory activity of 5-FU and MDTP in combination against MCF-7 in vitro, thus affirming their antitumor effects in vivo.

Androstanols↗