Mouse model for thoracic congenital scoliosis.

SUMMARY: This study sought to produce a dose-response curve for acute and chronic maternal carbon monoxide (CO) exposure versus vertebral anomalies in mouse offspring and to determine the critical day of exposure. In Part I, pregnant CD-1 mice were exposed to an acute dose of CO at 9 days of gestation. A positive dose-response relationship of acute maternal CO exposure and vertebral anomalies in the offspring was produced. In Part II, pregnant females were exposed to chronic CO for the first 11 days of gestation. Chronic exposure to CO did not produce significant vertebral anomalies. In Part III, pregnant females were exposed to an acute dose of 600 ppm of CO at gestation day 8, 9, or 10. Day 9 in this mouse breed is the critical day for maternal exposure to CO. The detected anomalies were predominately in the thoracic spine.     

邻苯二甲酸二乙基己酯对新生小鼠睾丸及Leydig细胞影响的实验研究

目的:探讨邻苯二甲酸二乙基己酯(DEHP)对新生小鼠睾丸及Leyd ig细胞形态结构及功能的影响。方法:DEHP分别以低、中、高3组剂量[100、200、500 mg/(kg.d)]灌胃作用于怀孕12 d到产后3 d(GD12~PND3)的KM母鼠,观察DEHP对新生雄性仔鼠体重、睾丸重量、Leyd ig细胞形态结构和3β-羟基类固醇脱氢酶(3-βHSD)活性、酶反应面积的影响。结果:DEHP作用于母鼠后,其雄性子代幼鼠体重和睾丸重量减轻,睾丸Leyd ig细胞形态、超微结构发生改变;高剂量组Leyd ig细胞数量明显增多;低、中剂量组睾酮合成关键酶3β-HSD酶活性下降,酶反应面积减小,但高剂量组在仔鼠出生后15 d时酶活性降低[(吸光度值(0.154±0.011)vs空白对照组(0.222±0.013),P<0.01],而酶反应面积增大[(6 303.0±745.6)μm2vs空白对照组(5 091.4±214.4)μm2,P<0.01)]。结论:DEHP能影响新生雄性小鼠体重、睾丸重量、Leyd ig细胞的形态结构和3β-HSD活性,具有抗雄激素效应。     

Effect of honey on the reproductive system of male rat offspring exposed to prenatal restraint stress

Exposure to prenatal stress is associated with impaired reproductive function in male rat offspring. Honey is traditionally used by the Malays for enhancement of fertility. The aim of this study was to determine the effect of honey on reproductive system of male rat offspring exposed to prenatal restraint stress. Dams were divided into four groups (n = 10/group): control, honey, stress and honey + stress groups. Dams from honey and honey + stress groups received oral honey (1.2 g kg^?1 body weight) daily from day 1 of pregnancy, meanwhile dams from stress and honey + stress groups were subjected to restraint stress (three times per day) from day 11 of pregnancy until delivery. At 10 weeks old, each male rat offspring was mated with a regular oestrus cycle female. Male sexual behaviour and reproductive performance were evaluated. Then, male rats were euthanised for assessment on reproductive parameters. Honey supplementation during prenatal restraint stress significantly increased testis and epididymis weights as well as improved the percentages of abnormal spermatozoa and sperm motility in male rat offspring. In conclusion, this study might suggest that supplementation of honey during pregnancy seems to reduce the adverse effects of restraint stress on reproductive organs weight and sperm parameters in male rat offspring.     

Long-term pulsed electromagnetic field (PEMF) results in congenital pseudarthrosis

Summary Ninety-one patients with congenital pseudarthrosis of the tibia have been treated with pulsed electromagnetic fields (PEMFs) since 1973 and all except 4 followed to puberty. Lesions were stratified by roentgenographic appearance. Type I and type II had gaps less than 5 mm in width. Type III were atrophic, spindled, and had gaps in excess of 5 mm. Overall success in type I and II lesions was 43 of 60 (72%). Of those 28 patients seen before operative repair had been attempted, 7 of 8 type I lesions healed (88%), whereas 16 of 20 type II lesions healed (80%) on PEMFs and immobilization alone. Only 19% (6 of 31) type III lesions united, only one of which did not require surgery. Sixteen of 91 limbs (18%) were ultimately amputated, most before treatment principles were fully defined in 1980. Fourteen of these 16 patients (88%) had type III lesions. Refracture occurred in 22 patients, most as the result of significant trauma, in the absence of external brace support. Twelve of the 19 refractures, retreated with PEMFs and casts, healed on this regime. Episodic use of PEMFs proved effective in controlling stress fractures in several patients until they reached puberty. PEMFs, which are associated with no known risk, appear to be an effective, conservative adjunct in the management of this therapeutically challenging, congenital lesions.     

不同治疗时间脉冲电磁场对去势大鼠股骨骨密度的影响

目的 通过采用不同治疗时间脉冲电磁场(pulsed electromagnetic fields, PEMFs)干预去势大鼠骨质疏松模型,观察大鼠股骨骨密度变化,探索PEMFs治疗骨质疏松症的最佳治疗时间.方法 将50只雌性3月龄SD大鼠随机分为假手术组、卵巢切除(ovariectomy, OVX)对照组、OVX后不同时间治疗组(OVX Ⅰ组、OVX Ⅱ组及OVX Ⅲ组),每组10只.假手术组大鼠仅切除卵巢周围部分脂肪组织,不切除卵巢;余各组大鼠均切除双侧卵巢,制备去势大鼠骨质疏松模型.OVX Ⅰ组、OVX Ⅱ组和OVX Ⅲ组大鼠每天分别用强度3.8×10-10A/m、频率8Hz干预20、40及60min,共30d;假手术组和OVX对照组不干预.观察各组大鼠一般情况,并于干预结束后次日处死大鼠,作左侧股骨骨密度测定.结果 术后OVX对照组大鼠毛发逐渐稀疏,活动迟缓,精神萎靡不振,反应较为迟钝;其余4组大鼠毛发光洁,精神及活动正常.假手术组、OVX对照组、OVX Ⅰ组、OVX Ⅱ组及OVX Ⅲ组股骨骨密度分别为(0.226±0.011)、(0.210±0.011)、(0.231±0.013)、(0.231±0.017)及(0.229±0.013)g/cm2,OVX对照组骨密度低于其他组(P<0.05),假手术组、OVX Ⅰ组、OVX Ⅱ组及OVX Ⅲ组组间比较,差异无统计学意义(P>0.05).结论 每日采用PEMFs对去势大鼠治疗20～60min能阻止其骨密度下降,接近正常水平,对骨质疏松症有良好的预防作用,且3种治疗时间对骨密度的维持效果相同.     

Maternal cannabinoid exposure Effects on spermatogenesis in male offspring

Maternal exposure to cannabinoids influenced spermatogenesis and fertility in their male offspring examined at 60-80 days of age. Approximately 20% less spermatozoa were found in males whose mothers had received either the non-psychoactive cannabinol (CBN) or cannabidiol (CBD) on day 1 postpartum. Males exposed to the major psychoactive component of marihuana, delta 9-tetrahydrocannabinol (THC) appeared to have spermatozoa in number comparable to controls. This finding may be consistent with the additional observation that CBN or CBD, but not THC, reduced the percentage of successful impregnations by cannabinoid-exposed males. However, males exposed to each of these cannabinoids produced significantly less live offspring compared to controls. Plasma levels of testosterone and luteinizing hormone (LH) were reduced significantly in mice exposed to THC on day 12 of gestation, while testicular weight was reduced in adult mice exposed either on day 12 of gestation to CBD or on day 1 post-partum to THC. These results indicate that perinatal exposure to psychoactive and non-psychoactive components of marihuana can produce long-term disruption of testicular function including the spermatogenic as well as the steroidogenic components.     

Effects of photoperiod on the ultrastructure of Leydig cells in rat

The aim of this study was to examine effects of photoperiod on the ultrastructure of Leydig cells in rat. For this purpose, 21 male Wistar rats were used. Animals were divided into three groups: Control rats in group I were kept under 12 hrs light: 12 hrs dark conditions (12L: 12D) for 10 weeks. Animals in group II were exposed to long photoperiods (18L: 6D), while rats in group III were exposed to short photoperiods (6L:18D) for 10 weeks. At the end of the experiment, all animals were killed by decapitation and blood samples were obtained. Serum testosterone levels were determined with the use of a chemiluminescent enzyme immunoassay. The testes of all rats were removed and weighed, then processed for light and electron microscopy. For morphometric comparison, diameters of seminiferous tubules in each group were measured. In rats exposed to long photoperiods, testicular weights, diameters of seminiferous tubules and serum testosterone levels were significantly increased as compared to those in control rats, whereas exposure of rats to short photoperiods resulted in a significant decrease of testicular weights, diameters of seminiferous tubules and serum testosterone levels as compared to those in control rats and rats maintained in long photoperiods. The amount of mitochondria and cytoplasmic secretory granules were increased in the cytoplasm of Leydig cells of rats exposed to long photoperiods. Furthermore, an increase in extensiveness of rough endoplasmic reticulum in the cell cytoplasm was noticed in this group, whereas a decrease in mitochondria and cytoplasmic secretory granules of the Leydig cell cytoplasm was seen in rats exposed to short photoperiods. The results of our study indicate that testicular functions increase after exposure to long photoperiods and decrease after exposure to short photoperiods.     

Dose-dependent effect of phthalate ester on testicular descent in pre-and post natal rats

Mono-n-butyl phthalate (MBP) was administered to pregnant rats from the 15th to the 17th gestational day to investigate the dose-dependent effect of phthalate ester on testicular descent in both pre- and postnatal rats. Thirty pregnant rats (280–330 g) were separated into five groups and administered 1.0 g/kg/day MBP in group I, 0.5 g/kg/day in group II, 0.25 g/kg/day in group III, 0.125 g/kg/day in group IV from the day 15 to 17 of gestation. The rats in group V were only administered solvent and acted as controls. The position of the testis was evaluated in both pre- and postnatal rats. This was significantly higher in 20-day old fetuses in groups I and II than in groups III, IV or V. After birth, the incidence of undescended testis was also higher in groups I and II compared with those of groups III, IV or V. The undescended testes were located in the abdominal cavity in groups I and II, whereas they were located at the inguinal region in group III. The lowest dose that induced an adverse effect on testicular descent was 0.25 g/kg/day. In conclusion, maternal MBP inhibited testicular descent in prenatal rats and thus dose-dependently induced undescended testes postnatally. High-doses of MBP are thus considered to inhibit the transabdominal descent of the testis, probably due to its estrogenic activity, whereas low-doses of MBP may act as an anti-androgen and thereby inhibit inguinoscrotal testicular descent in postnatal rats.     

Hepatic blood flow and drug metabolism in glycerol-rechallenged rats

Summary To analyze the hepatic blood flow and drug metabolism during glycerol-induced acute renal failure, 24 male Wistar rats were randomly divided into three groups: Group I received an intra-muscular injection of 1 ml/100g body weight 50% glycerol, group II a second injection on day 14 and group III a second injection on day 42 after the first injection respectively. The inulin clearance, the aminopyrine N-demethylase activity, the NADPH-cytochrome P-450 activity and the cardiac output and blood flow to the organs were measured before and after glycerol injection. The total hepatic and renal blood flow decreased less significantly in group II compared to group I and III. Various P 450 activities were kept on a high level only in group II. This observation indicates that the maintenance not only of renal but also of hepatic blood flow plays an important role in preventing the development of glycerol-induced acute renal failure. The mechanism may be the induction of various P 450 activities resulting in an increased hepatic clearance of nephrotoxic substances.Part of this paper was presented at the 9th Symposium of the Association for Experimental Urology of the German Urological Society, June 17–18, 1988, Aachen, Federal Republic of Germany     

Effect of transient embryonic in vivo exposure to the endocrine disruptor methoxychlor on embryonic and postnatal testis development

The current study was designed to examine the effects of a transient embryonic exposure to the pesticide methoxychlor, an endocrine disruptor, on in vivo rat testis development and function. Gestating female rats were transiently administered methoxychlor (MXC) from embryonic day 7 (E7; EO = plug date) through E15. Embryonic testes were collected at E16 and postnatal (PO = day of birth) testes at P4, P10, P17-20, and P60. Seminiferous cords formed in testes from MXC exposed males. However, at E16, there was a decrease in the area of cords and an increase in interstitial area in MXC exposed testes when compared with controls. At all postnatal ages collected, there did not appear to be differences in seminiferous cord/tubule area, interstitial area, or number of seminiferous cords/tubules between untreated controls and males exposed to MXC. Exposure to the endocrine disruptor also had no effect on the postnatal organ weights of a variety of different organs, nor were testosterone levels altered. Interestingly, there were reductions in the number of germ cells in testes from MXC-exposed males at P17-P20 when compared with untreated controls. Furthermore, there was a twofold increase in apoptotic cells in tubules from pubertal P17-P20-MXC exposed males when compared with untreated controls. Testes were collected from adult P60 males to determine if early embryonic and postnatal alterations in germ cell numbers or testis cellular composition had compromised spermatogenesis. In adult P60 MXC exposed testes there were no gross morphological changes in testis structure or cellular composition over that of controls. However, there was an increase in apoptotic cell number in elongating spermatids in MXC exposed testes. Four P60 males that were exposed to MXC during gestation and 4 control males were bred with unexposed females to determine their ability to produce offspring. All MXC exposed males were capable of impregnating females and had normal litter size and pup weights. Combined observations demonstrated that exposure to MXC during gestation at a critical stage of testis development (ie, sex determination) affects embryonic testis cellular composition, germ cell numbers, and germ cell survival. While alterations in these parameters does not affect the ability of males to produce offspring, there appears to be a reduced spermatogenic capacity associated with MXC treatment. Therefore, transient embryonic exposure to an endocrine disruptor (methoxychlor) during gestation can influence the germline and fertility in adult males.     

Coadministration of active phthalates results in disruption of foetal testicular function in rats

The reproductive effects of the coadministration of di-2-(ethylhexyl) phthalate (DEHP) and di-butyl phthalate (DBP) were studied in both foetal and adult male rat offspring exposed in utero . Pregnant Wistar rats were treated by oral gavage from gestation day 13 to 21 with vehicle control, 150 mg DEHP/kg body weight (bw)/day, 100 mg DBP/kg bw/ or a combination of the two compounds (DEHP 150 + DBP 100 mg/kg bw/day). An additional group of dams received 500 mg DBP/kg bw/day. A significant decrease in foetal testicular testosterone levels was observed in animals exposed to 500 mg DBP/kg/day or the phthalate mixture. Similarly, histological analysis of the foetal testis revealed that the coadministration of DEHP and DBP was able to increase the diameter of seminiferous cords and induce gonocyte multinucleation at doses that individually had no significant effects on these variables. However, in the phthalate mixture group, no significant changes were observed in anogenital distance and nipple retention, variables that are used to indicate possible anti-androgenic effects. Also, the adult endpoints investigated, that included reproductive organ weights and the number of spermatids per testis, were unaffected by any treatment regimen. Overall, coadministration of DEHP and DBP in utero significantly reduced testicular testosterone levels and resulted in misshapen seminiferous cords and gonocyte multinucleation in rat foetal testis. Our results also confirm that these foetal endpoints seem to be the most sensitive markers of prenatal phthalate exposure.     

Observations on offspring of mice made diabetic with streptozocin

My objective was to determine the effect of streptozocin (STZ)-induced diabetes in male inbred mice on nonfasting blood glucose levels and body weights of offspring. Hyperglycemia was induced in CBA/H male mice by either multiple subdiabetogenic doses (MD) of STZ (5 doses/day of 50 mg STZ/kg body wt) or by a single high sublethal (SD) dose (200 mg STZ/kg body wt). Females were made diabetic by the multiple low-dose procedure. The following matings were set up: SD males with normal (NOR) females; MD males with NOR females; NOR males with MD females; MD males with MD females. Controls were matings of NOR males with NOR females. Among the first cohort of litters was born one female from the cross of an SD male with an NOR female who became spontaneously hyperglycemic at 5 wk of age; the female progeny of this cross had significantly lower body weights. All other progeny groups were normoglycemic (up to 5 wk) and had normal body weights. Test progeny weaned in the second and subsequent cohorts of litters were also normoglycemic. The major effect in this progeny group was on body weight; diabetic fathers (particularly MD males) mated with NOR females produced offspring with significantly higher juvenile body weights than the controls (increase of approximately 0.5 g). These body-weight distributions also appeared more homogeneous than the more variable body-weight distribution of the controls. In contrast, MD mothers (mated with NOR males) produced second-cohort offspring with significantly lower average body weights (decrease of approximately 1-2 g) than the controls.(ABSTRACT TRUNCATED AT 250 WORDS)     

Prevention of acute lethal graft-versus-host disease in F1 hybrid mice by pretreatment of the graft with anti-NK-1.1 and complement.

We studied the effect of depleting NK1.1+ cells from an allograft of lymph node and spleen cells on the outcome of GVH disease in the parent----F1-hybrid combination C57BL/6----(C57BL/6xDBA/2)F1. Four treatment groups were established: group I mice were transplanted with an unmodified graft from normal donors; group II mice were transplanted with an NK1.1-depleted graft that had been harvested from normal donors; group III mice received grafts from donors that had been injected with Poly I:C (100 micrograms i.p.) 18 hr prior to harvesting (These grafts were incubated with complement, but no antibody.); group IV mice were transplanted with depleted grafts harvested from donors that had received Poly I:C. Recipients in each group were monitored for splenomegaly, mitogen responsiveness, NK and CTL activity, histopathology, weight loss, and mortality. Results showed that recipients in all four groups developed splenomegaly and unresponsiveness to LPS, PHA, and Con A by day 12. Augmented host-derived NK activity and graft-derived antihost CTL activity was also demonstrated. Group IV showed little or no weight loss, minimal histopathological changes and a marked reduction in mortality. Recipients in all other groups developed features characteristic of GVH disease and exhibited a steady decline in body weight beginning by day 12. Mortality generally began on day 18 and reached 75-90% by day 60. We postulate that anti-NK1.1 depletes cells from the graft are intimately connected with the effector mechanism in acute GVH disease.     

Metabolic and immune effects of enteral ascorbic acid after burn trauma.

A burned guinea-pig model (30 per cent BSA) was used to study the effect of vitamin C on immune and metabolic responses following burn trauma. Thirty-six guinea-pigs received identical enteral diets (175 kcal/kg) except for the amount of vitamin C. Groups I, II, III and IV were given formulae delivering no vitamin C, (1 RDA) 15 mg/kg/day, 75 mg/kg/day or 375 mg/kg/day, respectively. Resistance to infection was evaluated by injecting each animal with 0.1 ml of 1 x 10(9) Staph. aureus 502A subcutaneously on day 10. On day 14, Staph. aureus abscesses were excised and the numbers of viable colonies were determined. Results showed no statistical differences between groups in the clearance of Staph. aureus. From days 2 to 12, animals in groups I, II and III had body weights of approximately 97 per cent of preburn body weight. Animals in group IV, however, had a body weight gain, 102 per cent of preburn body weight on day 12. Animals in group IV also had significantly lower metabolic rates on day 12 as compared to the animals in the other groups. These results suggest that large amounts of vitamin C have beneficial effects on the maintenance of body weight and metabolic rate following burn trauma.     

Embryonic exposure to dimethoate and/or deltamethrin impairs sexual development and programs reproductive success in adult male offspring mice

Pesticides can be toxic to desirable plants and animals, including humans. The aim of this study was to investigate the reproductive effects of low doses of pesticides on male offspring of exposed pregnant mice. Three groups of five female mice were treated daily by oral gavage with dimethoate (5 mg kg(-1) per day), deltamethrin (5 mg kg(-1) per day) and their mixture at 5 mg kg(-1) per day from day 3 to day 21 of pregnancy. Fertility, sexual behaviour and a number of reproductive endpoints, such as organ weights, sperm evaluations and testicular histology, were examined on four adult male offspring of exposed pregnant mice. When compared with control, a dose of deltamethrin 5 mg kg j(-1) causes a decrease in the absolute and relative weight of the testes of exposed mice and it affects their fertility by reducing the density, mobility and vitality of sperm and increasing the number of abnormal forms of these cells (P ≤ 0.01). The same results were obtained in mice exposed to a dose of 5 mg kg j(-1) combination of dimethoate and deltamethrin. This study demonstrated that deltamethrin and combination of dimethoate and deltamethrin caused a decrease in the absolute and relative weight of the testes, which affected the sperm parameters of male offspring of exposed mice to a low dose of these pesticides during pregnancy.     

脊髓TNF-α在小鼠骨癌痛发生中的作用

目的 探讨脊髓TNF-α在小鼠骨癌痛发生中的作用.方法 雄性C3H/He小鼠72只,体重18～25 g,周龄4～6周,随机分为3组(n=24):假手术组(S组)、骨癌痛组(BCP组)和TNF-α拮抗剂依那西普组(E组).采用股骨远端骨髓腔注射肿瘤细胞的方法制备小鼠骨癌痛模型,S组注射等量不含肿瘤细胞的α-MEM,E组于注射肿瘤细胞前3 d、注射前即刻、注射后3、6 d时分别腹腔注射依那西普100μg(溶于0.5 ml生理盐水).分别于注射肿瘤细胞前、注射后3、5、7、10、14 d(T1～6)时测定热痛阈和机械痛阈.分别于T4～6时随机取8只小鼠测定痛阈后处死取脊髓,采用RT-PCR法检测TNF-αmRNA的表达水平.结果 与S组比较,BCP组T3～6时热痛阈和T5、6时机械痛阈降低,T4～6时TNF-αmRNA表达上调,E组T4～6时热痛阈降低,T5,6时机械痛阈降低、TNF-αmRNA表达上调(P<0.05);与BCP组比较,E组T4～6时热痛阈、T6时机械痛阚升高,T5,6时TNF-α mRNA表达下调(P<0.05).结论 脊髓TNF-α参与了小鼠骨癌痛的发生.     

The role of simvastatin on postoperative peritoneal adhesion formation in an animal model

AIM: The aim of this study is to show the effect of simvastatin on intra-abdominal adhesion formation. METHOD: Adhesion formation was achieved by scratching the cecum and anterior abdominal wall following median laparotomy. Three different groups of 10 rats each were formed. In group I, 0.57 mg/kg/day simvastatin was injected intraperitoneally right after the operation and for 5 days thereafter. In group II, an equal dose of simvastatin to that used in group I was given via gavage. A physiological saline solution was given to group III for the same period of time. On the 6th and 14th day, blood samples were taken and peritoneal lavage was performed to measure the tissue-type plasminogen activator (t-PA) activity. Adhesions were graded via re-laparotomies on the 14th day after the first operation. RESULTS: The adhesion scores were 1.40 +/- 0.22, 1.50 +/- 0.26, and 2.90 +/- 0.34 in groups I, II, and III, respectively (p = 0.007), and the score was higher in group III than in the other groups (p = 0.005, p = 0.011). CONCLUSION: Intraperitoneal simvastatin application decreases adhesion formation by increasing the t-PA level in abdominal surgery.     

邻苯二甲酸二(2-乙基)己酯对小鼠胎鼠睾丸及睾丸引带的影响

目的:研究邻苯二甲酸二(2-乙基)己酯(DEHP)对小鼠胎鼠睾丸与睾丸引带形态结构及功能的影响,探讨隐睾发生的可能机制。方法:30只健康KM孕鼠随机均分为3组:空白对照组、玉米油对照组、DEHP组。DEHP组以剂量500mg/(kg.d)的DEHP灌胃作用于怀孕12～19d(GD12～GD19)的KM母鼠,观察DEHP对每胎胎鼠数、雌雄性胎鼠比例、雄性胎鼠体重、睾丸重量、睾丸引带形态结构、位置、睾丸到膀胱颈之间的相对距离(TBD)、颅侧悬韧带残留情况、引带内雄激素受体(AR)、雌激素受体(ER)、肌动蛋白、增殖细胞核抗原(PCNA)表达水平的影响。结果:DEHP对每胎胎鼠数、雌雄性胎鼠比例、雄性胎鼠体重无明显影响;DEHP可影响胎鼠睾丸重量及TBD;DEHP组睾丸均有一定程度的下降不全,睾丸引带形态结构无明显差异;光镜下见DEHP组睾丸生精小管、支持细胞存在明显的发育障碍,睾丸Leydig细胞明显增生;DEHP组睾丸引带AR阳性表达率降低(P<0.01)。结论:DEHP可通过抗雄激素效应导致睾丸引带功能障碍,使睾丸下降发生异常而诱导小鼠隐睾;同时造成睾丸Ser-toli细胞、睾丸Leydig细胞和生精细胞的发育障碍和功能改变。     

Autologous blood transfusion with recombinant human erythropoietin in heart surgery--studies on the volume of preoperative donation and postoperative administration]

Recombinant human erythropoietin (rHuEPO) was administered to 42 elective heart surgery patients, and the volume of autologous blood donated within the preoperative short period and effects of improving anemia by postoperative rHuEPO administration were studied. rHuEPO (100 U/kg/day) and chondroitin sulfate-iron (40 mg/day) were given intravenously for preoperative 14 days, and each 400 ml of autologous blood was donated on the 14th and 4th day before operation. Reticulocytes increased significantly 3 days after administration (p less than 0.01). The hemoglobin level, 13.4 +/- 1.0 g/dl before the first donation, returned to 13.4 +/- 1.1 g/dl just before operation. 800 ml of autologous blood, needed for usual open heart surgery, may possibly have been donated within 14 days without making patients anemic by intravenous rHuEPO administration. For postoperative rHuEPO administration, the patients were divided into 3 groups: Group I (10 cases): given for 14 days, Group II (12 cases): for 7 days, Group III (20 cases): no administration. Reticulocytes decreased rapidly after termination of rHuEPO administration in each group, and on the 7th day after termination, they returned to the level before administration. The hemoglobin level in Group I was maintained after termination of rHuEPO, and was +2.2 +/- 1.1 g/dl on the 21st postoperative day compared with the level of 1st postoperative day. The hemoglobin level in Group II fell after termination and was +0.9 +/- 0.7 g/dl on the 21st day, this being comparable to the level of Group III. There were significant differences between Group I and II (p less than 0.05), and between Group I and III (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)