Inhibitory effect of chlorpromazine on rat reproduction: a test of administration for nine weeks before breeding

The effect of chlorpromazine (CPZ) administration prior to insemination on reproduction was studied using male and female Sprague-Dawley strain rats evaluated over three generations. CPZ in doses of 12.5, 25, 50, and 100 mg/kg was administered to both male and female rats orally every day for 9 weeks before mating with the following results: 1) The duration of the estrous cycle was prolonged in the F0 females. 2) The incidence of insemination and pregnancy of the F0 males and females as well as the number of surviving fetuses and newborns showed a tendency to decrease. 3) The body weight of the rats in F0 and F1 generations decreased depending on the dose of CPZ, but the body weight of the F2 generation increased. 4) The wet weight of the major organs of the rats in F0 and F1 generations was affected by administration of CPZ at 100 mg/kg. The weights of the liver, kidney, adrenal, pituitary, testis, and prostate glands in males and the kidney, adrenal gland, and ovary in females were increased, whereas the weights of the pituitary and the uterus were decreased in females. These results suggest that premating administration of CPZ to the parent rats exerts influence on the reproduction of the F0 and F1 generations.     

Small and intermediate conductance Ca<Superscript>2+</Superscript>-activated K<Superscript>+</Superscript> channels confer distinctive patterns of distribution in human tissues and differential cellular localisation in the colon and corpus cavernosum

The SK/IK family of small and intermediate conductance calcium-activated potassium channels contains four members, SK1, SK2, SK3 and IK1, and is important for the regulation of a variety of neuronal and non-neuronal functions. In this study we have analysed the distribution of these channels in human tissues and their cellular localisation in samples of colon and corpus cavernosum. SK1 mRNA was detected almost exclusively in neuronal tissues. SK2 mRNA distribution was restricted but more widespread than SK1, and was detected in adrenal gland, brain, prostate, bladder, liver and heart. SK3 mRNA was detected in almost every tissue examined. It was highly expressed in brain and in smooth muscle-rich tissues including the clitoris and the corpus cavernosum, and expression in the corpus cavernosum was upregulated up to 5-fold in patients undergoing sex-change operations. IK1 mRNA was present in surface-rich, secretory and inflammatory cell-rich tissues, highest in the trachea, prostate, placenta and salivary glands. In detailed immunohistochemical studies of the colon and the corpus cavernosum, SK1-like immunoreactivity was observed in the enteric neurons. SK3-like immunoreactivity was observed strongly in smooth muscle and vascular endothelium. IK1-like immunoreactivity was mainly observed in inflammatory cells and enteric neurons of the colon, but absent in corpus cavernosum. These distinctive patterns of distribution suggest that these channels are likely to have different biological functions and could be specifically targeted for a number of human diseases, such as irritable bowel syndrome, hypertension and erectile dysfunction.Abbreviations SK/IK/BK Small/intermediate/big conductance calcium-activated potassium channels respectively - AHP Afterhyperpolarisation - EBIO 1-ethyl-2-benzimidazolone - PCR Polymerase chain reaction - CNS Central nervous system     

Quantitative comparison of phosphodiesterase mRNA distribution in human brain and peripheral tissues

Cyclic nucleotide-specific phosphodiesterases (PDEs) play a critical role in signal transduction by regulating the level of adenosine 3′,5′-cyclic monophosphate (cAMP) and guanosine 3′,5′-cyclic monophosphate (cGMP) in cells. The gene expression pattern of a PDE provides important information regarding its role in physiological and pathological processes. In this study, we have established the mRNA expression profile all PDE isoenzymes (PDE1A/B/C, 2A, 3A/B, 4A/B/C/D, 5A, 6A/B/C, 7A/B, 8A/B, 9A, 10A, 11A) in a human cDNA collection consisting of 10 brain regions (parietal, frontal, temporal cortex, hippocampus, striatum, thalamus, hypothalamus, substantia nigra, nucleus accumbens, cerebellum), spinal cord, dorsal root ganglia and 12 peripheral tissues (skeletal muscle, heart, thyroid, adrenal gland, pancreas, bladder, kidney, liver, lung, small intestine, spleen, and stomach). Using quantitative real-time polymerase chain reaction and parallel analysis of a carefully selected group of reference genes, we have determined the relative expression of each PDE isoenzyme across the 24 selected tissues, and also compared the expression of selected PDEs to each other within a given tissue type. Several PDEs show strikingly selective expression (e.g. PDE10A and PDE1B mRNA levels in the caudate nucleus are 20-fold higher than in most other tissues; PDE1C and PDE3A are highly expressed in the heart and PDE8B is expressed very strongly in the thyroid gland). This comprehensive approach provides a coherent and quantitative view of the mRNA expression of the PDE gene family and enables an integration of data obtained with other non-quantitative methods.     

Pharmacokinetics of arbekacin in dogs. II. The distribution of arbekacin in tissues

A new aminoglycoside antibiotic, arbekacin (HBK) was intramuscularly and intravenously administered to Beagle dogs at a dose of 10 mg/kg to study its distribution into various tissues. The results obtained are summarized as follows. Biological half-lives of HBK in serum after intramuscular and intravenous injection were 1.15 hours and 1.00 hour after administration, respectively. These half-lives were similar to the results obtained in previous studies. Maximum concentrations of HBK in tissues and biological fluids after intramuscular injection were the highest in kidney followed by vagina, serum, urinary bladder, uterus, ovarium, lung, parotid gland, trachea, tonsil, gall bladder, pericardiac fluid, thymus, muscle, heart, liver, mandibular gland, bile, aqueous humor, pancreas, cerebrospinal fluid and brain, in this order. Maximum concentrations were found at 4 hours in trachea, aqueous humor and cerebrospinal fluid, and at 2 hours in pericardiac fluid. In other tissues and biological fluids, they were obtained at 0.5-1 hour. Maximum concentrations in tissues and biological fluids after 1 hour intravenous injection were the highest in kidney followed by serum, ovarium, vagina, lung, parotid gland, urinary bladder, uterus, spleen, thymus, pericardiac fluid, gall bladder, trachea, tonsil, heart, liver, pancreas, muscle, mandibular gland, bile, aqueous humor, cerebrospinal fluid and brain in this order. Maximum concentrations were found at 4 hours in trachea, cerebrospinal fluid and bile, and at 2 hours in pericardiac fluid. In other tissues and biological fluids, they were obtained at the end of the infusion. Maximum concentrations in these biological fluids after both intramuscular and intravenous injection were similar to serum concentrations except kidney, trachea, and other biological fluids.(ABSTRACT TRUNCATED AT 250 WORDS)     

Tissue-specific induction of cytochromes P450 1A1 and 1B1 by polycyclic aromatic hydrocarbons and polychlorinated biphenyls in engineered C57BL/6J mice of arylhydrocarbon receptor gene

Tissue-specific induction of mRNA of cytochrome P450 (P450 or CYP) 1A1 and 1B1 by polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) was investigated in wild and arylhydrocarbon receptor (AhR)-deficient C57BL/6J mice. Ratios of mRNA expression of CYP1A1 or CYP1B1 over beta-actin were determined and used to compare levels of expression and induction of these P450s by PAHs and PCBs in various organs. CYP1A1 mRNA was detected in control mice at very low levels in liver, lung, heart, kidney, intestine, thymus, testis, uterus, ovary, and brain and was highly induced in these organs by benzo[a]pyrene and 3,4,3',4'-tetrachlorobiphenyl in AhR(+/+) mice. In AhR(+/+) and AhR(-/-) mice, CYP1B1 mRNA was found to be constitutively expressed at significant levels in heart (the ratio of mRNAs of CYP1B1 to beta-actin was approximately 0.6), kidney ( approximately 0.8), intestine ( approximately 0.3), testis ( approximately 0.9), thymus ( approximately 0.4), uterus ( approximately 0.3), ovary ( approximately 1.4), and brain ( approximately 0.4), whereas it was low in liver and lung (the mRNA ratio to beta-actin was <0.2 in these cases). CYP1B1 in the latter two organs was highly induced by PAHs and 3,4,3',4'-tetrachlorobiphenyl in AhR(+/+) mice. The induction of CYP1B1 by PAHs and PCBs was more extensive in organs in which the constitutive expression of CYP1B1 was low. For example, CYP1B1 was induced 9-fold and 10-fold by benzo[a]pyrene and 3,4,3',4'-tetrachlorobiphenyl in livers of male and female mice, respectively, whereas in testis and ovary, the fold induction of CYP1B1 by two inducers was only 1.1 and 1.4, respectively. Liver microsomal xenobiotic oxidation activities were induced by these PAHs and PCBs in male and female AhR(+/+) mice. These results suggest that CYP1A1 and CYP1B1 are differentially regulated in their expression in extrahepatic organs of mice and could be induced by PAHs and PCBs with different extents of induction depending on the inducers used and the organs examined in AhR(+/+) mice. The findings of significant levels of constitutive expression of CYP1B1 in AhR(-/-) mice as well as AhR(+/+) mice in several organs including heart, kidney, thymus, testis, ovary, and brain in AhR(-/-) mice as well as AhR(+/+) mice are of importance in understanding the basis of toxicity and carcinogenesis by chemicals that are metabolized by CYP1B1.     

Reabsorption of neutral amino acids mediated by amino acid transporter LAT2 and TAT1 in the basolateral membrane of proximal tubule

In order to understand the renal reabsorption mechanism of neutral amino acids via amino acid transporters, we have isolated human L-type amino acid transporter 2 (hLAT2) and human T-type amino acid transporter 1 (hTAT1) in human, then, we have examined and compared the gene structures, the functional characterizations and the localization in human kidney. Northern blot analysis showed that hLAT2 mRNA was expressed at high levels in the heart, brain, placenta, kidney, spleen, prostate, testis, ovary, lymph node and the fetal liver. The hTAT1 mRNA was detected at high levels in the heart, placenta, liver, skeletal muscle, kidney, pancreas, spleen, thymus and prostate. Immunohistochemical analysis on the human kidney revealed that the hLAT2 and hTAT1 proteins coexist in the basolateral membrane of the renal proximal tubules. The hLAT2 transports all neutral amino acids and hTAT1 transports aromatic amino acids. The basolateral location of the hLAT2 and hTAT1 proteins in the renal proximal tubule as well as the amino acid transport activity of hLAT2 and hTAT1 suggests that these transporters contribute to the renal reabsorption of neutral and aromatic amino acids in the basolateral domain of epithelial proximal tubule cells, respectively. Therefore, LAT2 and TAT1 play essential roles in the reabsorption of neutral amino acids from the epithelial cells to the blood stream in the kidney. Because LAT2 and TAT1 are essential to the efficient absorption of neutral amino acids from the kidney, their defects might be involved in the pathogenesis of disorders caused by a disruption in amino acid absorption such as blue diaper syndrome.     

Estrogen-like activity of tamoxifen and raloxifene on NMDA receptor binding and expression of its subunits in rat brain.

Hormonal specificity of modulation of N-methyl- D-aspartate (NMDA) receptors was investigated by comparing the effects of estradiol with tamoxifen or raloxifene, which display different responses in breast, bone, and uterus. Two weeks ovariectomy in rats decreased uterine weight, which was prevented by a two-week estradiol treatment; tamoxifen and raloxifene had weaker uterine stimulation than estradiol. Ovariectomy in rats decreased L-[3H]glutamate specific binding to NMDA receptors in CA1 and dentate gyrus but not CA2/3 regions of hippocampus and was without effect in cortex, striatum, nucleus accumbens, and olfactory tubercle. [3H]Ro 25-6981 (an NMDA antagonist selective for NR1/NR2B assembly) specific binding and mRNA levels of NMDA receptor subunits 1 and 2B decreased in CA1 after ovariectomy. Estradiol, tamoxifen, and raloxifene decreased L-[3H]glutamate specific binding to NMDA receptors and [3H]Ro 25-6981 specific binding in cortical area of ovariectomized rats and prevented the decrease of [3H]glutamate specific binding to NMDA receptors in CA1 and dentate gyrus, as well as [3H]Ro 25-6981 specific binding in CA1. Estradiol prevented the decrease of NMDA receptor subunits 1 and 2B mRNA levels in CA1 only; tamoxifen and raloxifene prevented the decrease of NMDA receptor subunit 1 mRNA levels in CA1. No effect of ovariectomy or treatments on L-[3H]CGP 39653 (an NMDA antagonist selective for NR1/NR2A assembly) specific binding and NMDA receptor subunit 2A mRNA levels was observed in all brain regions assayed. Our results showed brain regional and subunits specific agonist estrogenic activity of tamoxifen and raloxifene on NMDA receptors.     

甘糖酯在小鼠体内的药代动力学研究

用同位素标记法研究了[~3H]甘糖酯1次灌胃后在小鼠体内的药代动力学,其血药浓度——时间曲线符合一室开放模型。小鼠灌服[~3H]甘糖酯25mg/kg(4.48MB_q/kg)后的药动学参数为:t_(1/2)Ka 0.24h;t_(1/2)β67h,V_d921mL,Cl9.58ml/h,AUC41.45mg/(mL·h),F79.3％,PPB54.9％。该药广泛分布于肝、肾、脾、胸腺、肾上腺、肺、心、肌肉和脑内。主要经尿道与粪便排泄。     

Organic anion transporting polypeptides (OATPs): regulation of expression and function

Eleven members of the human organic anion transporter (OATP) family (grouped into six families) facilitate the Na(+)- independent transmembrane transport of various endo- and xenobiotics (bile acids, bilirubin, steroid hormone conjugates, thyroid hormones, prostaglandins, clinically used drugs, and toxins). OATPs are 12-transmembrane glycoproteins (643-722 amino acids) and contain many conserved structural features, for example, eleven cysteines in the large extracellular loop 5. They are important for proper transport, for which translocation of substrates through a central, positively-charged pore in a rocker-switch-type mechanism has been proposed. Although OATPs are expressed in various cells and tissues, some members show a more restricted pattern (well-studied OATP1B1/OATP1B3 in liver, OATP4C1 in kidney, and OATP6A1 in testis). In cancer, the distribution pattern is no longer maintained, and OATPs, like OATP1B3, become upregulated in malignant tissues (colon, breast, prostate). Studies in cell lines and animal models further revealed that the expression of OATPs is regulated in a cell- and tissue-specific way by cytokines and activation of nuclear receptors (LXR, FXR, PXR, CAR, HNF4). Also epigenetic mechanisms and postranslational modifications influence their expression and function. Therefore, changes in the expression of OATPs under pathological conditions will influence transport processes causing an altered accumulation of OATP substrates in cells of excretory organs (intestine, liver, kidney) and on various blood/organ barriers (such as brain, testis, placenta). For drugs, this may result in increased toxicity and adverse drug reactions. Therefore, it is important to improve the knowledge on the regulation and function of individual OATPs, and to apply it for therapeutic considerations.