TrkB is involved in the mechanism by which BDNF accelerates the glutamate-induced death of rat neuroblastoma B35 cells.

OBJECTIVE: Brain-derived neurotrophic factor (BDNF) binds to its high-affinity binding receptor, tropomyosin-related kinase (Trk) B, and can induce neuronal differentiation and survival. BDNF also accelerates neuronal cell death in a glutamate-induced model; however, it has been unknown whether the mechanism involves TrkB. In the current study, to determine the role of TrkB in neuronal cell death, we investigated TrkB involvement in BDNF acceleration of glutamate-induced neuronal death. METHODS: A TrkB-stable transformant of rat neuroblastoma B35 (B35(TrkB)) cells was utilized to investigate whether TrkB is involved in BDNF acceleration of neuronal death. The cell viability of the B35(TrkB) cells was compared to that of mock vector-transgened B35 (B35(mock)) cells after treatment with/without BDNF and glutamate. RESULTS: In both B35(TrkB) and B35(mock) cells, glutamate treatment decreased the cell viability. BDNF treatment further accelerated the decrease in the viability of B35(TrkB) cells, but not that in the viability of B35(mock) cells. At glutamate concentrations that did not significantly decrease cell viability, BDNF increased the cell viability of B35(TrkB), but not that of B35(mock). A mitogen-activated protein kinase (MAPK) inhibitor, U0126, suppressed BDNF's accelerating effect on cell death. Although B35 parental cells endogenously express other neurotrophin receptors such as TrkA, nerve growth factor ß (a ligand of TrkA and p75(NTR)) could not influence the viability of B35(TrkB) or B35(mock) cells. CONCLUSION: These results indicate that TrkB is an intermediator for the trophic and toxicity-exacerbating effects of BDNF against cell viabilities at non-cytotoxic and cytotoxic glutamate concentrations, respectively.

Urinary carbonic anhydrase VI as a biomarker for kidney disease in pigs.

This study investigated whether carbonic anhydrase (CA)-VI has utility as a biomarker in swine kidney disease. Serum chemistry, histopathology, immunohistochemical staining and enzyme-linked immunosorbent assay (ELISA) analyses were performed. In the kidney of normal healthy pigs, CA-VI was localized in the epithelial cells of the renal distal straight tubules. CA-VI levels were 16 ± 35 ng/g wet tissue and 50 ± 66 ng/mL in normal pig kidney and urine, respectively, and 136 ± 173 ng/mL in the urine of pigs with kidney disease. CA-VI urinary concentration was not correlated with urinary urea nitrogen (UUN), urinary creatinine (Cre), or urinary albumin levels in pigs with kidney disease. However, UUN and Cre levels were positively correlated in the urine of pigs with kidney disease. These data suggest that urinary CA-VI may represent a biomarker for kidney disease in pigs, particularly for disorders affecting distal straight tubules.

Isolation and sequencing of swine carbonic anhydrase VI, an enzyme expressed in the swine kidney.

BACKGROUND: Carbonic anhydrase VI (CA-VI) is produced by the salivary gland and is secreted into the saliva. Although CA-VI is found in the epithelial cells of distal straight tubule of swine kidneys, the exact function of CA-VI in the kidneys remains unclear. RESULTS: CA-VI was located in the epithelial cells of distal straight tubule of swine kidneys.A full-length cDNA clone of CA-VI was generated from the swine parotid gland by reverse transcription polymerase chain reaction, using degenerate primers designed based on conserved regions of the same locus in human and bovine tissues. The cDNA sequence was 1348 base pairs long and was predicted to encode a 317 amino acid polypeptide with a putative signal peptide of 17 amino acids. The deduced amino acid sequence of mature CA-VI was most similar (77.4%) to that of human CA-VI. CA-VI expression was confirmed in both normal and nephritic kidneys, as well as parotid. As the primers used in this study spanned two exons, the influence of genomic DNA was not detected. The expression of CA-VI was demonstrated in both normal and nephritic kidneys, and mRNA of CA-VI in the normal kidneys which was the normalised to an endogenous ß-actin was 0.098 ± 0.047, while it was significantly lower in the diseased kidneys (0.012 ± 0.007). The level of CA-VI mRNA in normal kidneys was 19-fold lower than that of the parotid gland (1.887). CONCLUSIONS: The localisation of CA-VI indicates that it may play a specialised role in the kidney.

Acetylcholine esterase is a regulator of GFAP expression and a target of dichlorvos in astrocytic differentiation of rat glioma C6 cells.

The main target of neurotoxins is neurons because they comprise the main part of neural function, but glial cells may be indirect targets because they support the function of neurons. Among the glial cells, astrocytes in particular act as "nurse cells", regulating neuronal survival and functions. In the present study, to reveal whether a known neurotoxic substance, organophosphate dichlorvos (DDVP), affects the differentiation of astrocytes, we used an astrocyte differentiation model in rat glioma C6 cells. Morphological change and induction of GFAP expression in the differentiating C6 cells were suppressed by DDVP treatment. The known potential targets of DDVP are acetylcholine esterase (AChE), fatty acid amide hydrolase and methyl guanine methyl transferase. Among the specific inhibitors against these enzymes, the AChE inhibitor paraoxon successfully suppressed the cellular morphological changes and the induction of GFAP expression in differentiating C6 cells. These results indicate that DDVP inhibits differentiation in the C6 astrocyte-differentiation model, in which at least AChE inhibition is involved and that AChE is a potent regulator of the differentiation. Furthermore, considering that the main substrate of AChE is ACh, thus, ACh may act as regulators of astrocyte differentiation.

Culture on a fragmin/protamine-coated plate suppresses the collagen type IαI and TGF-ß1 mRNA expression of rat hepatic stellate RI-T cells.

Hepatic stellate cells (HSCs) intracellularly preserve vitamin A in the normal liver. When the liver is damaged, HSCs transform into myofibroblast-like cells, and then proliferate and increase their expression of collagen. Cultured on a plastic plate, HSCs spontaneously activate. To maintain HSCs in a quiescent state with low expression of collagen, coating methods with extracellular matrixes (ECMs) such as Matrigel-coating or laminin-rich coating are commonly used for HSC cultivation. Kishimoto et al. [14] reported that Fragmin®/protamine microparticles (F/P-MPs) have the ability to absorb heparin-binding cytokines like ECMs. Therefore, we examined whether the cultivation on an F/P-MPs-coated plate maintains the quiescent state of RI-T cells (derived from rat HSCs) including the suppression of collagen expression. We found that the mRNA levels of collagen type IαI and TGF-ß1 in RI-T cells were significantly suppressed in the cultivation on F/P-MPs-coated plates compared to cultures on noncoated and Matrigel-coated plates. We conclude that the F/P-MPs coating method is useful for maintaining with low expressions of collagen IαI and TGF-ß 1 mRNA levels in HSCs.

Measurement of Carbonic Anhydrase I and II Isozymes in Feces as a Marker of Occult Blood in Horses with Intestinal Tract Bleeding.

Although endoscopy is the definitive diagnostic method for the detection of colonic ulcers, the equipment required for performing the test is costly and difficult to use. Therefore, a simple cost-effective and reliable screening test for intestinal tract bleeding is needed. To this end, we measured carbonic anhydrase isozymes (CA-I and CA-II) originating from erythrocytes by ELISA in order to determine if they could be used as markers of occult blood in feces. For fecal extract preparation, 2 g of feces were mixed with 4 ml of 0.01 M Tris-HCl (pH 8.0) containing 0.01% thimerosal. The concentrations of CA-I and CA-II in the fecal samples of 13 clinically normal racehorses were found to be 30.0 ± 10.0 and 34.0 ± 13.0 ng/ml, respectively. Increased concentrations of CA-I were detected in the fecal samples of 5 horses after blood administration; however, no increase was observed in CA-II. The concentrations of CA-I and CA-II in the fecal samples of 88 racehorses with clinical signs of equine gastric ulcer syndrome (EGUS) were 115.3 ± 79.0 and 41.0 ± 42.0 ng/ml, respectively. Thus, our results indicate that CA isozymes can be useful as markers of occult blood in the fecal samples of horses with intestinal tract bleeding.

Muscle carbonic anhydrase III levels in normal and muscular dystrophia afflicted chickens.

BACKGROUND: The levels and immunohistochemical localization of muscle carbonic anhydrase III (CA-III) in healthy chickens and in muscular dystrophia affected (DA) chickens show that the muscles of diseased animal undergo a progressive increase of enzyme activity. METHODS: An enzyme-linked immunoassay was used to assess the CA-III levels in the muscles and other tissues from eight normal White Leghorn chickens and in two chickens with muscular dystrophy. Immunohistochemical localization of the enzyme in the muscles of these animals was also determined. RESULTS: The levels of CA-III in the tensor fasciae latae and the superficial pectoral muscles of the DA chickens were higher than the level in normal chickens. The concentrations of CA-III in erythrocytes and plasma from diseased chickens were approximately 15-fold and 1.4-fold higher than in the normal chickens, respectively. In the superficial pectoral and the tensor fasciae latae muscles of diseased chickens, the numbers of strongly stained and weakly stained fibers were greater than that in the normal chickens. CONCLUSION: The levels of CA-III in the superficial pectoral muscle, the tensor fasciae latae muscle, plasma and erythrocytes from the chickens with muscular dystrophy were higher than found in normal chickens.

Maternal exposure to low doses of DES altered mRNA expression of hepatic microsomal enzymes in male rat offspring.

Our previous studies demonstrated that prenatal diethylstilbestrol (DES) treatment disrupts steroidogenesis but induces high-level expression of androgen receptor (AR) mRNA to inhibit the disruption of spermatogenesis. This study examined which prenatal DES treatment influenced hepatic microsomal enzymes, CYP3A1, CYP2B1/2, CYP2C11, UGT2B1 (UDP-glucuronosyltransferase 2B1), and IGF-1 (insulin-like growth factor-1), in male rat offspring. DES treatment decreased the mRNA expression levels of CYP3A1 and CYP2B1/2, but did not alter the expression of CYP2C11. At 6 weeks, DES treatment increasd the mRNA expression levels of UGT2B1 and IGF-1. These results suggest that prenatal DES treatment alters two hepatic enzymes (CYP3A1 and CYP2B1/2) and IGF-1 mRNA expression levels to counteract the low level of testosterone, but this disrupted UGT2B1 mRNA expression reduces the testosterone level.

Measurement of carbonic anhydrase isozyme VI (CA-VI) in swine sera, colostrums, saliva, bile, seminal plasma and tissues.

Swine secretory carbonic anhydrase VI (CA-VI) was purified from swine saliva and an antibody to CA-VI was generated. A specific and sensitive enzyme-linked immunosorbent assay (ELISA) has been developed for the measurement of swine CA-VI. The assay can detect as little as 5 ng/mL of swine CA-VI. Typical standard curves were determined for a range of CA-VI solutions (7.8 to 500 ng/mL). The coefficients of variation for these solutions were less than 5%. When 500, 250 or 100 ng/mL of swine CA-VI was added to swine sera, the recoveries were 102.0%, 109.7% and 100.2%, respectively. The concentrations of CA-VI in the saliva (26.2 ± 30.4 µg/mL), sera (3.3 ± 4.9 ng/mL), bile (153.0 ± 114.0 ng/mL), seminal plasma (124.0 ± 39.0 ng/mL) and parotid gland (441.3 ± 90.0 µg/g wet tissue), submaxillary gland (88.1 ± 124.4 µg/g wet tissue), sublingual gland (58.6 ± 24.6 µg/g wet tissue) and gallbladder (2.4 ± 1.3 µg/1g wet tissue) were determined by ELISA. The concentration of CA-VI in colostrum was 163.3 ± 101.4 ng/mL and did not decrease within 10 days following parturition. An immunohistochemical reaction to anti-CA-VI antiserum was observed in the columnar epithelial cells lining the gallbladder. These data suggest that secretory CA-VI plays various roles in pH regulation and the maintenance of ion and fluid balance.

Vitamin K has the potential to protect neurons from methylmercury-induced cell death in vitro.

Vitamin K (VK) has a protective effect on neural cells. Methylmercury is a neurotoxicant that directly induces neuronal death in vivo and in vitro. Therefore, in the present study, we hypothesized that VK inhibits the neurotoxicity of methylmercury. To prove our hypothesis in vitro, we investigated the protective effects of VKs (phylloquinone, vitamin K(1); menaquinone-4, vitamin K(2) ) on methylmercury-induced death in primary cultured neurons from the cerebella of rat pups. As expected, VKs inhibited the death of the primary cultured neurons. It has been reported that the mechanisms underlying methylmercury toxicity involve a decrement of intracellular glutathione (GSH). Actually, treatment with GSH and a GSH inducer, N-acetyl cysteine, inhibited methylmercury-induced neuronal death in the present study. Thus, we investigated whether VKs also have protective effects against GSH-depletion-induced cell death by employing two GSH reducers, L-buthionine sulfoximine (BSO) and diethyl maleate (DEM), in primary cultured neurons and human neuroblastoma IMR-32 cells. Treatment with VKs affected BSO- and DEM-induced cell death in both cultures. On the other hand, the intracellular GSH assay showed that VK(2), menaquinone-4, did not restore the reduced GSH amount induced by methylmercury or BSO treatments. These results indicate that VKs have the potential to protect neurons against the cytotoxicity of methylmercury and agents that deplete GSH, without increasing intracellular GSH levels. The protective effect of VKs may lead to the development of treatments for neural diseases involving GSH depletion.

Biochemical and developmental characterization of carbonic anhydrase II from chicken erythrocytes.

BACKGROUND: Carbonic anhydrase (CA) of the chicken has attracted attention for a long time because it has an important role in the eggshell formation. The developmental profile of CA-II isozyme levels in chicken erythrocytes has not been determined or reported. Furthermore, the relations with CA-II in erythrocyte and egg production are not discussed. In the present study, we isolated CA-II from erythrocytes of chickens and determined age-related changes of CA-II levels in erythrocytes. METHODS: Chicken CA-II was purified by a combination of column chromatography. The levels of CA-II in the hemolysate of the chicken were determined using the ELISA system in blood samples from 279 female chickens, ages 1 to 93 weeks, 69 male chickens, ages 3 to 59 weeks and 52 weeks female Araucana-chickens. RESULTS: The mean concentration of CA-II in hemolysate from 1-week-old female was 50.8 ± 11.9 mg/g of Hb. The mean levels of CA-II in 25-week-old (188.1 ± 82.6 mg/g of Hb), 31-week-old (193.6 ± 69.7 mg/g of Hb) and 49-week-old (203.8 ± 123.5 mg/g of Hb) female-chickens showed the highest level of CA-II. The levels of CA-II in female WL-chickens significantly decreased at 63 week (139.0 ± 19.3 mg/g of Hb). The levels of CA-II in female WL-chicken did not change from week 63 until week 93.The mean level of CA-II in hemolysate of 3-week-old male WL-chickens was 78.3 ± 20.7 mg/g of Hb. The levels of CA-II in male WL-chickens did not show changes in the week 3 to week 59 timeframe. The mean level of CA-II in 53-week-old female Araucana-chickens was 23.4 ± 1.78 mg/g of Hb. These levels of CA-II were about 11% of those of 49-week-old female WL-chickens. Simple linear regression analysis showed significant associations between the level of CA-II and egg laying rate from 16 week-old at 63 week-old WL-chicken (p<0.01). CONCLUSIONS: Developmental changes and sexual differences of CA-II concentration in WL-chicken erythrocytes were observed. The concentration of CA-II in the erythrocyte of WL-chicken was much higher than that in Araucana-chicken (p<0.01).

Corticosterone synthesis inhibitor-induced decrease in the age-dependant expression of nitric oxide synthase 3 in the preterm ductus arteriosus of rats.

Previous studies have shown that the dilating effect of nitric oxide (NO) on the fetal ductus arteriosus (DA) is age dependent and more marked in the premature stages in rats, but the factors that mediate this effect are poorly understood. The purpose of this study is to determine the changes in the expression of NO synthase (NOS) mRNA in the fetal DA and to examine the effect of an 11-beta-hydroxylase inhibitor of corticosterone synthesis, namely, metyrapone, on NOS expression. NOS 3 mRNA expression was observed in 17.5-day-old rat fetuses; thereafter, its level significantly increased and reached its peak on day 19.5 and then decreased until the end of the gestation period (day 21.5). To inhibit corticosterone synthesis, a constant infusion of metyrapone was administered to rats; this significantly decreased the fetal plasma corticosterone concentration as well as NOS 3 mRNA expression in the DA in a time-dependent manner. These results indicate that NO is generated by NOS 3 in the DA and that the age-dependant expression of NOS 3 in the premature DA is attributable to corticosterone-associated activity.

Effects of maternal exposure to low doses of DES on testicular steroidogenesis and spermatogenesis in male rat offspring.

Our previous studies have demonstrated that prenatally administered diethylstilbestrol (DES) impairs testicular endocrine function in male offspring. The present study examined whether maternal DES treatment influences testicular steroidogenesis and spermatogenesis. DES was injected subcutaneously at 0.5 or 1.5 microg/kg/day (DES 0.5 and 1.5 groups, respectively) into pregnant SD rats on days 7-21 of gestation. Male offspring in the DES 0.5 and 1.5 groups were autopsied at 1, 3, 6 and 15 weeks after birth. At 1 week, DES treatment did not lead to a change in the volume of P450scc-positive cells (Leydig cells), suggesting that DES has no inhibitory effect on the development of Leydig cells. DES administration disrupted luteinizing hormone receptor (LHr) expression and exerted inhibitory effects on signal transduction from LHr to steroidogenic acute regulatory protein (StAR) in testicular steroidogenesis (P<0.05), although there were no changes in the mRNA expression levels of steroidogenic enzymes, such as P450scc, 3beta-hydroxysteroid dehydrogenase (3beta-HSD) and P450(17 alpha), which may have caused a decrease in the plasma testosterone level. DES treatment did not disrupt the cycle of spermatogenesis but did upregulate the expression levels of androgen receptor (AR) mRNA in both DES groups at 15 weeks (P<0.05). These results indicate that maternal DES treatment disrupts steroidogenesis but induces a high level of AR mRNA expression to counteract the low levels of testosterone during spermatogenesis.

Acceleration of methylmercury-induced cell death of rat cerebellar neurons by brain-derived neurotrophic factor in vitro.

Brain-derived neurotrophic factor (BDNF) is a member of the nerve growth factor (NGF) family and has been shown to promote neuronal survival and contribute to neural development. Although methylmercury, a neurotoxin, induces the cell death of neurons in vitro, there is little information regarding the effects of neurotrophins on the methylmercury-induced cell death of neurons. In the present study, we investigated the effect of BDNF on methylmercury-induced cell death in a primary culture of rat cerebellar granular cells. BDNF increased the viability of the cultured cells when treated alone, but unexpectedly accelerated the cell death induced by administration of methylmercury. Among other growth factors tested, only neurotrophin-4 (NT-4) demonstrated a similar acceleration of methylmercury-induced cell death. The cell death-accelerating effect of BDNF was inhibited by a BDNF-neutralizing antibody or a MAPK inhibitor. To determine whether the effect of BDNF occurs via TrkB, a receptor of BDNF and NT-4, we investigated the effects of BDNF and methylmercury in a TrkB transformant of rat neuroblastoma B35 cells. The methylmercury-induced cell death of the TrkB transformant was accelerated by BDNF, while that of the mock transformant was not. These results indicate that BDNF accelerates methylmercury-induced cell death via TrkB, at least in vitro, and suggest that BDNF and TrkB may also contribute to the sensitivity of neurons to methylmercury toxicity.

Effects of maternal exposure to diethylstilbestrol on epididymal development in rat offspring.

In our previous study, prenatal diethylstilbestrol (DES) exposure (days 7-21 of gestation) suppressed plasma testosterone levels and histological development in the epididymis of rat offspring. In this study, we measured cell proliferation in epididymal ductules and the expression of steroid hormone receptors and 5alpha-reductase 1 in the epididymis to assess the effect of DES on epididymal development in the offspring. Prenatal DES exposure did not alter the cell division index, but suppressed the expression of androgen receptor mRNA at 15 weeks after birth, and stimulated estrogen receptor alpha mRNA at 6 weeks. These results suggest that prenatal DES exposure results in the retardation of epididymal tissue maturation by disruption of the postnatal expression of steroid hormone receptors.

Developmental toxicity of indium: embryotoxicity and teratogenicity in experimental animals.

Indium, a precious metal classified in group 13 (IIIB) in the periodic table, has been used increasingly in the semiconductor industry. Because indium is a rare metal, technology for indium recycling from transparent conducting films for liquid crystal displays is desired, and its safety evaluation is becoming increasingly necessary. The developmental toxicity of indium in experimental animals was summarized. The intravenous or oral administration of indium to pregnant animals causes growth inhibition and the death of embryos in hamsters, rats, and mice. The intravenous administration of indium to pregnant animals causes embryonic or fetal malformation, mainly involving digit and tail deformities, in hamsters and rats. The oral administration of indium also induces fetal malformation in rats and rabbits, but requires higher doses. No teratogenicity has been observed in mice. Caudal hypoplasia, probably due to excessive cell loss by increased apoptosis in the tailbud, in the early postimplantation stage was considered to account for indium-induced tail malformation as a possible pathogenetic mechanism. Findings from in vitro experiments indicated that the embryotoxicity of indium could have direct effects on the conceptuses. Toxicokinetic studies showed that the embryonic exposure concentration was more critical than the exposure time regarding the embryotoxicity of indium. It is considered from these findings that the risk of the developmental toxicity of indium in humans is low, unless an accidentally high level of exposure or unknown toxic interaction occurs because of possible human exposure routes and levels (i.e. oral, very low-level exposure).

Involvement of independent mechanism upon poly(ADP-ribose) polymerase (PARP) activation in methylmercury cytotoxicity in rat cerebellar granule cell culture.

Poly(ADP-ribose) polymerase (PARP) activation plays a role in repairing injured DNA, while its overactivation is involved in various diseases, including neuronal degradation. In the present study, we investigated the use of a PARP inhibitor, 3,4-dihydro-5-[4-(1-piperidinyl)butoxy]-1(2H)-isoquinolinone (DPQ), whether methylmercury-induced cell death in the primary culture of cerebellar granule cells involved PARP activation. DPQ decreased the methylmercury-induced cell death in a dose-dependent manner. Unexpectedly, this protective effect was DPQ specific; none of the other PARP inhibitors--1,5-dihydroxyisoquinoline, 3-aminobenzamide, or PJ34--affected neuronal cell death. Methylmercury-induced cell death involves the decrease of glutathione (GSH) and production of reactive oxygen species. Therefore, to understand the mechanism by which DPQ inhibits cytotoxicity, we first studied the effect of DPQ on buthionine sulfoximine- or diethyl maleate-induced death of primary cultured cells and human neuroblastoma IMR-32 cells, both of which are mediated by GSH depletion. DPQ inhibited the cell death of both cultured cells, but it did not restore the decrease of cellular GSH by buthionine sulfoximine to the control level. Second, we evaluated the antioxidant activity of PARP inhibitors by methods with ABTS (2-2'-azinobis(3-ethylbenzothiazoline 6-sulfonate) or DPPH (1,1-diphenyl-2-picrylhydrazyl) used as a radical because antioxidants also efficiently suppress methylmercury-induced cell death. The antioxidant activity of DPQ was the lowest among the tested PARP inhibitors. Taken together, our results indicate that DPQ effectively protects cells against methylmercury- and GSH depletion-induced death. Furthermore, they suggest that DPQ exerts its protective effect through a mechanism other than PARP inhibition and direct antioxidation, and that PARP activation is not involved in methylmercury-induced neuronal cell death.

Effects of growth factors on development of fetal islet B-cells in vitro.

To investigate the role of growth factors (epidermal growth factor [EGF], betacellulin, and activin A) in the development of islet B cells of rat fetal pancreatic explants in vitro, pancreases from rat fetuses at day 18 of gestation were cultured for 96 hr, with or without these growth factors. Culture medium was changed every 24 hr, and the level of insulin released in the culture medium was measured. After 72 hr of culture, pancreases were examined histologically. As a result, EGF promoted cell proliferation, but reduced B cell volume. Whereas, betacellulin and activin A inhibited cell division, but promoted increased B cell volume and insulin secretion, especially activin A, which stimulated insulin release in a time dependent manner. These results suggest that EGF, betacellulin, and activin A promote pancreatic cell proliferation, islet B-cell differentiation, and islet B-cell differentiation and functional maturation, respectively, and that EGF, betacellulin, and activin A, in this order, regulate islet B-cell neogenesis.

The herbal medicine Tokishakuyakusan increases fetal blood glucose concentrations and growth hormone levels and improves intrauterine growth retardation induced by N(omega)-nitro-L-arginine methyl ester.

N(omega)-Nitro-L-arginine methyl ester (L-NAME) induces a pre-eclampsia-like syndrome in pregnant rats. We have previously reported the anti-hypertensive effects of several Japanese traditional (Kampo) medicines in this model, and one of these, Tokishakuyakusan (TS), also improved intrauterine growth retardation (IUGR). In the present study, we characterized the effect of TS on IUGR. TS administration reversed the decrease in fetal body weight and fetal blood glucose concentration induced by the infusion of L-NAME. Growth hormone (GH) levels in the fetal blood, which were decreased by L-NAME infusion, were also significantly elevated by TS; however, levels of GH releasing hormone (GHRH) and insulin-like growth factor I (IGF-I) were unchanged and only slightly changed, respectively. Treatment with L-NAME with or without TS had no apparent effect on GH, GHRH, and IGF-I levels of dams. In an immunocytochemical study, the number of GH-positive cells in the fetal pituitary gland was significantly increased in TS-treated rats. These data suggest that enhanced proliferation of somatotrope cells of the pituitary gland and the resultant increase in GH secretion in the fetus may be involved in the improvement of IUGR by TS.

The herbal medicines Saireito and Boiogito improve the hypertension of pre-eclamptic rats induced by Nomega-Nitro-L-arginine methyl ester.

The chronic inhibition of nitric oxide (NO) synthesis with N(omega)-Nitro-L-arginine methyl ester (L-NAME) induces a pre-eclampsia-like syndrome including hypertension in pregnant rats. We tested the traditional herbal medicines Saireito (SR) and Boiogito (BO), which have been used clinically for the treatment of pre-eclampsia, in this model. L-NAME was infused subcutaneously into pregnant rats from gestational day 14 (G14). SR and BO (both at 1, 2g/kg) were administered by gavage from G14 to G20. Systolic blood pressure was measured on G19. SR and BO (both at 1, 2g/kg) inhibited L-NAME-induced hypertension. SR was effective in both pregnant and non-pregnant rats while BO was effective only in pregnant rats. BO increased blood levels of CGRP and decreased levels of endothelin-1; both are known to play important roles in regulation of blood pressure in pre-eclampsia. SR and BO may be beneficial for the treatment and prevention of hypertension in pre-eclampsia.