Effects of feeding endophyte infected tall fescue seed on reproductive performance of female CD-1 mice via competitive breeding

This study was conducted to determine the effects of feeding endophyte-infected (Acremonium coenophialum ) tall fescue (Festuca arundinacea ) seed on the growth and reproductive performance of female CD-1 mice via competitive breeding. One hundred sixty female mice were randomly allocated to groups of ten and fed one of two diets. Diet 1 consisted of 50% mouse chow and 50% noninfected Ky-31 tall fescue seed (w/w). Diet 2 contained 50% chow and 50% tall fescue seed that was 80% infected with A. coenophialum . After 50 d of preconditioning on their respective diets, a single male was introduced into each group of 10 females and allowed to cohabitate for 96 h. The males were removed after the cohabitation period and the females continued through gestation on their respective diets. Body weight of dams and litter weights were recorded at parturition. There were no differences (P>0.05) in pregnancy rates between dietary Treatments 1 and 2 (50% vs 48.8%, respectively). However, the average number of pups born per litter (11.10 pups) and average total litter weight (17.21 g) was greater for those females consuming Diet 1 than for females consuming Diet 2 (9.33 pups per litter and 13.97 g total litter weight). The incidence of dead and cannibalized pups was more frequent with Diet 2 than Diet 1 (0.13 vs 0.0 dead; 0.21 vs 0.03 cannibalized, respectively). The obtained data suggest that although the pregnancy rate was similar between the two dietary treatments, the reproductive capacity (litter size and litter weight) of female CD-1 mice was affected by the consumption of endophyte infected fescue seed.     

Lactation in mice fed endophyte-infected tall fescue seed

This study was conducted to assess the effects of endophyte-infected Acremonium coenophialum tall fescue (KY-31) seed (80% infected) on lactation in CD-1 dams and suckling performance of pups as measured by pup survival and growth rates. Twenty-four pairs of mature CD-1 mice were randomly allocated to four dietary treatments: 1) 100% mouse chow ad libitum; 2) 40% endophyte-infected tall fescue seed and 60% mouse chow (w/w); 3) reduced intake (100% chow), adjusted daily to the intake level of Treatment 2; and 4) 60% infected tall fescue seed and 40% chow. The mice were preconditioned on their respective diets for 100 d prior to 96 h of cohabitation between pairs of males and females. At parturition the litters were removed, and each dam was given a litter of six pups of equal weight, size and sex ratio to suckle for 15 days. All pups given to all the dams were born to other mice that were not part of the study and had not been exposed to endophyte-containing diets. Dams and litter weights were measured daily for 15 consecutive days. The combined body weight measurements of litters from dams fed the tall fescue containing diets (Treatments 2 and 4) were significantly lower (2.07 +/- 0.41 g/d) than that of litters from dams fed the chow containing diets (Treatments 1 and 3) during the suckling trial (P<0.05). Similarly, nine of ten (90%) dams fed the chow containing diets maintained five or more pups (5.5 +/- 0.2) throughout the study as compared to five of nine (55.6%) dams fed the tall fescue containing diets that maintained less than five pups (4.5 +/- 0.2).     

Effect of feeding fungal endophyte (Acremonium coenophialum )-infected tall fescue seed on reproductive performance in CD-1 mice through continuous breeding

This study was designed to assess the effect of endophyte-infected (Acremonium coenophialum ) tall fescue (KY-31) seed (80% infected) on reproductive performance in CD-1 mice by continuous breeding. Twenty-four pairs of 70-d-old CD-1 mice were randomly allocated to four diets: 1) mouse chow ad libitum; 2) 40% infected fescue seed and 60% chow (w/w); 3) reduced intake (100% chow) similar to the intake, adjusted daily, in Diet 2; and 4) 60% infected fescue seed and 40% chow. Males and females were randomly paired (six pairs/treatment) and placed on the above diets. The mice were fed the corresponding diets for 80 d, although the pairs were separated on Day 60 (prior to the birth of the 3rd litter) and the females were monitored for one additional gestation period (20 d). The pregnancy data (litters produced) among the four treatments were 100.0 (18), 77.8 (14), 100.0 (18) and 80.0% (12) respectively. Similarly, the average number of pups born per litter among the four treatments was 11.8, 9.3, 10.1, and 9.8. When the chow treatment (1 and 3) and the fescue treatments (2 and 4) were pooled and compared, the percent pregnancy was 100.0 (n = 36) and 78.8 (n = 26), and the pups born per litter (means +/- SEM) were 11.0 +/- 0.5 and 9.5 +/- 0.6, respectively. Also the intervals between the three litters born during the 60-d cohabitation period were 21.6 +/- 1.1 and 24.5 +/- 0.9 d for the chow and fescue treatments, respectively. The results point out that 40 and 60% infected fescue seed in the diet of mice does influence (P < 0.05) their reproductive capacity as measured by percent pregnancy and litter size.     

Effects of feeding endophyte-infected tall fescue seed on the reproductive performance in male and female CD-1 mice by combination crosses

The present study was undertaken to assess the effects of endophyte-infected Acremonium coenophialum tall fescue (KY 31) seed (80% infected) on the reproductive performance of male and female CD-1 mice by combination crosses. Forty-eight male and 48 female 30-d-old mice were randomly allocated to two diet treatments. Twenty-four males and 24 females were fed Diet 1, consisting of 50% non-infected fescue and 50% mouse chow; the remaining animals were fed Diet 2, containing 50% infected fescue. At the end of 50 d, the animals were paired in groups (n = 12) as follows: 1) Diet 1 males and females; 2) Diet 2 males and Diet 1 females; 3) Diet 1 males and Diet 2 females; and 4) Diet 2 males and females. The pairs were maintained on the diets of their female partners and were allowed to cohabitate for 96 h. After this period the males were removed and the females were carried to term. Pregnancy rates among the four treatment groups were 100, 83.3, 75.0 and 54.5%, respectively. Similarly, the average number of pups born per litter among the four groups were 11.5, 8.0, 9.7, and 7.5, respectively. Also, the weights (grams) of pups born per litter were 17.5, 12.6, 12.4, and 9.8, respectively. The results point out that the reproductive capacity of both male and female mice are affected (P < 0.05) by the ingestion of endophyte-infected fescue seeds. Such negative effects were more severe in the female than the male (P < 0.05).     

Effects of feeding endophyte-infected tall fescue seed on reproductive performance in male CD-1 mice by competitive breeding

The objective of this study was to assess the effects of endophyte-infected tall fescue (KY-31) seed (80% infected, containing Acremonium coenophialum ) on the reproductive performance of male CD-1 mice measured by competitive breeding. Sixteen mature CD-1 male mice were randomly allocated to one of two dietary treatments containing 50% mouse chow and either 1) 50% noninfected tall fescue seed, restricted to the daily feed intake of dietary treatment 2, or 2) 50% infected tall fescue seed (w/w) fed ad libitum. Mice were preconditioned on their respective diets for 50 d prior to 96 h of cohabitation with 10 mature CD-1 females. Following removal of males, the females were carried to full term. Males were sacrificed, and testicular, epididymal weights, sperm motility and progressive sperm motility were assessed. The results showed no differences (P>0.05) in average daily weight gain (ADG) and body weight changes during the course of the experiment between the two dietary treatments. There were significant reductions (P<0.05) in total testes weight (0.238 vs 0.214 g), epididymal weight (0.087 vs 0.073 g), sperm motility (82.5 vs 58.7%), and progressive motility (3.7 vs 2.6; scale 0 to 4) between dietary treatments 1 and 2, respectively. Similarly, significant differences in pregnancy rates were 53.8 and 45.0%, and the average numbers of pups born per litter were 10.67 and 9.84, respectively. These data suggest that 50% endophyte-infected fescue seed in the diet of male CD-1 mice can affect their reproductive capacity by influencing the testicular-epididymal weights, and subsequently, the quality of spermatozoa and overall fecundity.     

Effects of consuming endophyte-infected tall fescue on growth, reproduction and lactation in mice selected for high fecundity

Effects of a diet containing endophyte-infected tall fescue seed (83% infected) were investigated using 2 lines of mice, one line selected for fecundity (L(+)) and the other a randomly selected control line (K). Treatments included a commercial stock diet (C), 50% stock plus 50% non-infected tall fescue seed (N), and 50% stock plus 50% infected tall fescue seed (I). The experiment was conducted using mice on respective treatments in 2 phases (successive generations), with 15 to 23 mated females per line and diet subgroups. Mated females of Phase 1 were assigned at random within line to experimental diets which were fed during gestation and through 21 d of lactation. Litters were standardized to 10 pups 1 d after birth. Stock diets were fed to all groups from Day 21 to weaning on Day 28. Weaned male and female pups were allotted to previous diets. Mated females in Phase 2 were managed as in Phase 1 through weaning at 28 d. Diets of males did not affect reproduction and data were pooled within female diets. Selected (L(+)) dams gave birth to more live pups than K dams (P<0.05) during both phases (+3.4 and +2.8 +/- 0.4 pups, respectively). Diet but not line affected littering rate of mated females in Phase 1 (71.3%, I; < 87.1%, C or 93.0%, N; P<0.05) and Phase 2 (82.1%, I < 93.8%, N or 97.1%, C; P<0.05). Diet had no effect on fecundity during Phase 1 but females on I diet had reduced (P<0.05) litter size by 1.9 and 3.2 +/- 0.5 pups compared with the females on N and C diets, respectively, in Phase 2. Feed consumption and weights of dams during lactation generally ranked C>N>I. Growth of pups during both phases also ranked C>N>I. Vaginal opening at 28 d differed by line (71.4%, K < 89.3%, L(+), P<0.05) and diet (56.8%, I < 92.0%, C or 92.2%, N, P<0.05). These results suggest both acute and chronic effects of consumption of endophyte-infected diets. Absence of line-by-diet interactions demonstrates that adverse effects were unrelated to genetic differences between lines.     

The effect of feeding tall fescue seed infected by Acremonium coenophialum on pregnancy and parturition in female rats

1. Female Sprague-Dawley rats (Rattus norvegicus) were randomly assigned to various dietary treatments containing: (1) 100% Purina rodent chow, ad libitum; (2) same as 1, but restricted to daily intake of 7; (3) 50% rodent chow (w/w) and 50% endophyte-free tall fescue (Festuca arundinacea) seed; (4) same as 3, but restricted to intake of 5; (5) 50% rodent chow, 25% endophyte-free tall fescue seed and 25% endophyte-infected (Acremonium coenophialum) tall fescue seed; (6) 50% rodent chow, 12.5% endophyte-free and 37.5% endophyte-infected tall fescue seed; and (7) 50% rodent chow and 50% endophyte infected tall fescue seed. 2. Average daily feed intakes and average daily weight gains decreased with higher levels of endophyte infected seed. 3. Frequency of litter production was affected by all endophyte-infected containing diets. 4. Conception was reduced only in dietary treatment (7). 5. Litter weights, number of pups per litter and weight per pup were proportionally reduced as higher levels of infected seed were incorporated in the ingested diets.     

Fertilization rates and embryonic development in CD-1 mice fed fungal endophyte-infected tall fescue seed

The objective of this study was to assess the effects of endophyte-infected tall fescue (KY-31) seed (80% infected, containing Acremonium coenophialum ) on the fertilization rates and embryonic development of CD-1 mice. Twenty-four pairs of mature CD-1 mice were randomly allocated to two dietary treatments containing 40% mouse chow and 1) 60% noninfected tall fescue seed or 2) 60% infected tall fescue seed (w/w). The mice were preconditioned on their respective diets for 60 d prior to 96 h of cohabitation between pairs of males and females. Following the removal of the males, equal numbers of females (n = 4) from each dietary treatment were sacrificed at 80 h, 6 and 10 d after vaginal plug establishment. The female reproductive tracts were excised and flushed to recover eggs and embryos or dissected to identify the number and status of the implanted fetuses. The number of eggs-embryos and/or fetuses per mouse present at the time of sacrifice were 9.8, 8.8 and 11.5 vs 8.2, 5.3 and 4.8 for the mice fed the noninfected and infected fescue seeds, respectively. Similarly, the conception rates (%) were 100, 100 and 100 vs 73, 50 and 50 for the two treatments. The mice sacrificed at 80 h and fed the noninfected fescue had 9.8 expanded blastocysts per animal, whereas those fed the infected fescue had only 4.0 expanded blastocysts. The results suggest that the infected fescue seed consumed by these mice had a significant effect on fertilization rates. More importantly, the infected fescue seed influenced negatively the development of these embryos during the embryonic-preimplantation period.     

Effect of feeding tall fescue seed infected by endophytic fungus (Acremonium coenophialum ) on reproductive performance in male rats

An experiment was conducted to determine the effect of feeding tall fescue seed infected by an endophytic fungus Acremonium coenophialum on the reproductive performance of male rats. Thirty 70-day-old rats were randomly allocated to four treatments: (I) fed 50% rat chow and 50% healthy fescue seed ad libitum (control; N=9; (II) same as I but restricted to the daily feed intake of III (N=7; (III) 50% fungal-infected fescue seed and 50% chow (N=7); and (IV) a mixture of 50% laboratory chow, 25% healthy fescue seed and 25% fungal-infected fescue seed (N=7). The rats were fed these diets for 42 days. During this time, body weights were taken weekly and feed intake was taken daily. At the end of the experiment, the rats were sacrificed and the testes and epididymides were excised and measured. Sperm parameters were assessed (concentration, percentage of motility and progressive motility) at the site of the cauda epididymis; the testes were homogenized and assessed for daily sperm production potential (DSP). Concentrations of spermatozoa (x 10(6)) among the various treatments were 645.6, 486.5, 387.4 and 457.1; motility and progressive motility measurements ranged from 48 to 50% and 2.3 to 2.4 (0-4), respectively. DSP values (per gram) and testicular weight were reduced (P<0.05) in Diet III. The data suggests that 50% fungal-infected fescue seed in the diet of rats does influence the DSP, testicular parechyma and epididymal weight in the rat.     

Sex-specific embryonic mortality during concurrent pregnancy and lactation in house mice

To evaluate the importance of lactational stress for sex ratio manipulation in postpartum inseminated house mice, 163 sexually inexperienced male and female BALB/c ABom inbred mice were mated and stud males were removed the day following the initial parturition. Randomly chosen dams were allowed to suckle their young for either one or 14 or 21 days. The results showed that two weeks of lactation enhance the incidence of total abortion of the litter conceived postpartum. If lactation continued another week, dams which gave birth to a second litter lost relatively more embryos during uterine development and the percentage of lost embryos was increased by the number of pups suckled. Among these dams, the number of embryos lost in utero correlated positively with viable litter sex ratios (percentage male pups) at second parturition, indicating that lactational stress enhances embryonic mortality and that this additional mortality predominantly affects female embryos.     

儿童单纯性肥胖小鼠模型的制作

目的通过调整窝仔数的方法建立幼儿单纯性肥胖模型,并与高脂饲料制备模型进行比较。方法48只雌性KM小鼠产仔鼠后,一半仔鼠数目为14～16只,一半仔鼠调整为6只（雌雄各3只）。仔鼠离乳时或第9周时仔鼠分别饲喂普通饲料或高脂饲料。仔鼠在15周后处死,称重,测量体长、腰围,生殖器重、脂肪重（肾周和生殖器周脂肪）,计算体脂比。结果①BD2组常规饲料饲喂至15周结束后,无论雌雄仔鼠,其体重与BDl组比较差异均有显著性（P〈0．05）,且BD2组体重超过BD1组体重雌性为26．3％,雄性为20．0％。同一处理方式,雌性仔鼠体脂比均高于雄性。②不同时间饲喂高脂饲料,无论调整窝仔数与否,高脂饲料各组仔鼠,无论雌雄,其各组仔鼠体重均比BD1组高（P均〈0．05）;HFD4组雌性和雄性仔鼠体重与BD2组相比差异均存在显著性（P〈0．05）。结论通过调整窝仔数的方法可以成功制备儿童单纯性肥胖模型。在儿童早期肥胖的情况下,成年后过度高脂饮食会导致机体储存更多的脂肪。     

High fat diet induced oxidative DNA damage estimated by 8-oxo-7,8-dihydro-2-deoxyguanosine excretion in rats

The role of dietary fats and energy in carcinogenesis has been partly related to oxidative damage to DNA. We have investigated the effect of dietary fat content and saturation on the urinary excretion of 8-oxo-7,8dihydro-2'-deoxyguanosine (8-oxodG) in male and female rats. Groups of Fischer F344 rats (n = 6-10) were fed control chow (3.4% fat) or diets containing 21.8% corn oil or 19.8% coconut oil + 2% corn oil for 12-15 weeks. At the end of the diet intervention period 24h urine was collected for determination of 8-oxodG by HPLC. In the male groups fed control, corn oil and coconut oil diet the excretion of 8-oxodG was 403+/-150, 932+/-198 and 954+/-367pmol/kg 24 h, respectively (p < 0.05). In the female groups fed control and corn oil diet the excretion of 8-oxodG was 752+/-80 and 2206+/-282 pmol/kg 24 h, respectively (p < 0.05). Calculated per whole animal the excretion was 137+/-51, 324+/-70 and 328+/-128 pmol/24 h in the control, corn and coconut oil male groups and 156+/-21 and 464+/-56 pmol/24 h in the control and corn oil female groups, respectively ( p < 0.05). Thus, per animal or per consumed energy there was much less difference in 8-oxodG excretion between the corresponding male and female groups and only significant difference between the high fat groups. There was a close correlation (r = 0.7; p < 0.05) between 8-oxodG excretion and the energy intake. The present study suggests that a high fat diet increases oxidative DNA modification substantially irrespective of the saturation level of the fat. Energy intake appears to be the major determinant of the rate of modification.     

The induction of parturition in the bitch using sodium cloprostenol

The objectives of this studies were to determine a continuous low-dose treatment regimen for the administration of sodium cloprostenol to the bitch that did not cause polydipsia, and whether this treatment would induce normal and timed parturition in bitches during late pregnancy. Non-pregnant greyhound bitches (n=18) received sodium cloprostenol subcutaneously, via a miniosmotic pump, at dose rates of 0.875 to 4.5 microg/kg/24 h, for 7 days (Days 0 to 7). Daily water intake was measured from Day -2 to Day 9. Polydipsia was observed in bitches treated with the higher dose rates but not in bitches treated with the lowest dose rate of 0.875 microg/kg/24 h. In the second experiment, pregnant greyhound bitches received sodium cloprostenol at dose rates of 1 (n=4), 2 (n=1) and 3 microg/kg/24 h (n=1), on Day 57 of pregnancy. Polydipsia was observed in bitches treated at the higher dose rates of 2 and 3 microg/kg/24 h, but not in the bitches treated at the lower dose rate of 1 microg/kg/24 h. These treatments resulted in the successful induction of parturition. Parturition was associated with a decrease in plasma progesterone concentrations, a reduction in body temperature, and an increase in plasma concentrations of 13,14-dihydro-15-keto prostaglandin F2alpha. The first puppy was born 37.7 +/- 2.9 h after the start of treatment (range 28 to 46 h). The duration of whelping was approximately 15.7 +/- 2.2 h (range 10 to 24 h). The litter size was 9.2 +/- 0.8 pups (range 6 to 12 pups), and the puppy survival rate was 6.0 +/- 0.8 per litter (range 4 to 9 pups). This study demonstrated that the administration of sodium cloprostenol in continuous low dose for 24 h is an effective treatment for the induction of parturition in bitches during late pregnancy. This treatment resulted in the birth of healthy pups, with minimal or no side effects to the bitch.     

Do Laboratory Mouse Females that Lose Their Litters Behave Differently around Parturition?

Efficiency in laboratory mouse breeding is hampered by poor reproductive performance, including the loss of entire litters shortly after birth. However, the underlying mechanisms are not yet fully understood and establishing the cause of death in laboratory mouse pups can be complicated. Newborn mouse pups are generally hidden in nests, dead pups are often eaten by the female, and the widespread practice of leaving periparturient females undisturbed complicates inspection, which may delay the discovery of pup loss. In order to efficiently prevent problems with litter loss, it is important to find key factors for survival. We investigated differences in periparturient behavior between female laboratory mice whose pups survived until weaning and females whose entire litters were lost. Video recordings of 82 primiparous females of the C57BL/6 strain or knockouts with C57BL/6 background were used. The mice were observed from 24 h before until 24 h after parturition and female behaviors coded using a pre-established ethogram. The relationship between behavior and survival was analyzed using logistic models, where litter survival was regressed on the proportion of 30-s observations with at least one occurrence of the behavior. We found that females with surviving litters performed more nest building behavior during the last 24 h before parturition (p = 0.004) and spent less time outside the nest during the entire observation period (p = 0.001). Increased litter survival was also associated with more passive maternal behaviors and the female ignoring still pups less. Females that lost their litters performed more parturition-related behaviors, suggesting prolonged labor. The results indicate that maternal behavior plays a significant role in laboratory mouse pup survival. Complications at parturition also contribute to litter mortality.     

Maternal Aggression and Litter Size in the Female House Mouse

It has been commonly argued that, in house mice, female post-partum fighting against a male intruder functions to protect the offspring from infanticide. The aim of this study was to test the hypothesis that maternal aggression is actually related to pup defence and, specifically, according to parental investment theory, that its intensity should increase with litter size. 60 nulliparous albino female mice were mated and randomly assigned to four experimental groups in which litters were culled at birth to 0, 4, 8, or 12 pups, respectively. On day 8 after delivery all females were tested for maternal aggression against a stranger adult male conspecific (5-min exposure). No aggression occurred in the group in which all pups had been removed. In the other groups, the proportion of females displaying overt aggression increased with litter size. Several scores of female agonistic behaviour (proportion of females displaying overt aggression, total attacking time, frequency of tail rattling) were significantly higher for the females rearing 8 and 12 pups than for the females rearing 4 pups. Aggressive behaviour of females rearing 12 pups was not significantly higher than that of females rearing 8 pups. No male committed infanticide. These results support the hypothesis that rodent maternal aggression is strictly related to offspring defence and are consistent with the theoretical prediction that, the costs of the defence being equal and the gain in fitness increasing with litter size, the intensity of maternal defence of the young should increase with their number.     

The effects of gender and obesity on myocardial tolerance to ischemia

Obesity is increasing at an alarming rate globally. Several studies have shown that premenopausal women have a reduced risk of CV disease and a reduced myocardial susceptibility to ischemia/reperfusion injury. The effect of obesity on myocardial tolerance to ischemia in women has not been established. To determine how obesity affects myocardial susceptibility to ischemia/reperfusion injury in both males and females, we fed male and female Wistar rats a high caloric diet (HCD) or a control rat chow diet (CD) for 18 weeks. Rats were subsequently fasted overnight, anesthetized and blood was collected. In separate experiments, 18-week-fed (HCD and CD) rats underwent 45 min in vivo coronary artery ligation (CAL) followed by 2 hours reperfusion. Hearts were stained with TTC and infarct size determined. Both male and female HCD fed rats had increased body and visceral fat weights. Homeostasis model assessment (HOMA) index values were 13.95+/-3.04 for CD and 33.58+/-9.39 for HCD male rats (p<0.01) and 2.98+/-0.64 for CD and 2.99+/-0.72 for HCD fed female rats. Male HCD fed rats had larger infarct sizes than CD fed littermates (43.2+/-9.3 % vs. 24.4+/-7.6 %, p<0.05). Female HCD and CD diet fed rats had comparable infarct sizes (31.8+/-4.3 % vs. 23.9+/-3.3 %). We conclude that male rats on the HCD became viscerally obese, dyslipidemic and insulin-resistant, while female HCD fed rats became viscerally obese without developing dyslipidemia or insulin resistance. Obesity increased myocardial infarct size in males but not the females.     

The effects of elk velvet antler consumption on the rat: development, behavior, toxicity and the activity of liver gamma-glutamyltranspeptidase

The effect of exposure to, followed by consumption of, a diet containing 10% powdered elk velvet antler (EVA) from the 18th day of gestation to the 88th day after birth was examined in male and female Fischer 344 rats. There were no teratogenic effects of EVA exposure in utero or differences in birth outcomes between pups born to regular chow fed and EVA chow fed dams. Growth curves of the EVA fed rats were identical to those of regular chow fed rats, as were developmental milestones of pinna development and eye-opening. Acoustical startle and righting reflexes, developmental and behavioral indices, were identical. Blood glucose levels were comparable in EVA chow fed and regular chow fed rats, indicating that EVA is without effect on glucose balance. There were no signs of toxicity in the EVA chow fed compared to regular chow fed rats as judged from plasma enzyme markers of liver damage: plasma levels of alanine aminotransferase were 50% lower in EVA chow fed rats compared to regular chow fed rats; and plasma levels of gamma-glutamyltranspeptidase (gammaGT) were the same. The activity of gammaGT displayed a decrease in the livers of EVA chow fed rats, more so in the male (22%) than in the female (14%), suggestive of an androgenic effect. A possible hepatobeneficial effect of the EVA induced decrease in liver gammaGT is discussed. In summary, dietary10% EVA chow is without long term effect on growth, development and behavior is non-toxic and may be hepatobeneficial.     

Renal function and glucose transport in male and female mice with diet-induced type II diabetes mellitus

The aim of this study was to measure cardiovascular and renal function, including the renal transport capacity for glucose, in male and female C57BL/6J mice with diet-induced Type II diabetes mellitus. Typical of Type II diabetes, mice fed a high-fat, high-simple carbohydrate diet for 3 months were obese (45-65 g), hyperglycemic (138-259 mg%), and hyperinsulinemic (1.8-15.06 ng/ml); significant gender differences were observed in all cases. Based on systolic pressure measurements in conscious mice and arterial blood pressure measurements in anesthetized mice, no diet-induced hypertension was observed in either male or female mice. Urine flow rate, sodium, potassium, osmolar, and protein excretion rates were significantly increased (P < 0.05) in male mice fed the high-fat, high-simple carbohydrate diet compared with female mice fed the same diet. However, no differences in the excretion variables existed between male and female mice fed the control diet. The glomerular filtration rate (ml min-1 g kw-1), determined by FITC-inulin, in male and female mice fed the control diet (0.87 +/- 0.01 and 0.90 +/- 0.1, respectively) and high-fat, high-simple carbohydrate diet (0.96 +/- 0.1 and 0.93 +/- 0.2, respectively) was not different between the groups. These hyperglycemic mice were also not glucosuric. Infusions of progressive amounts of glucose in male mice fed either diet for 3 or 6 months demonstrated that the renal threshold for glucose was 400 mg% for all these mice, well above the fasting plasma glucose concentrations observed in this study. Thus, C57BL/6J mice were valuable tools for studying diet-induced obesity, hyperglycemia, and hyperinsulinemia; however, no hypertension or kidney dysfunction was apparent within the time frame of the current study.     

The influence of dietary copper on reproduction, growth and the cardiovascular system in Swiss-Webster female mice

One hundred forty pubertal Swiss-Webster female mice (Mus musculus) were assigned randomly to a purified diet modified to contain 1, 2, 3, 4, 5 and 6 ppm copper as copper carbonate (Diets 1 thru 6, respectively). Diet 7 was a commercial rodent laboratory diet containing 11 ppm copper. Following 60 days of prefeeding, the breeding regimen was initiated by introducing a proven breeder male into each cage of 10 females in the afternoon and removing them the next morning. The breeding regimen was conducted for 28 days and females were either sacrificed at 24 or 96 hours following detection of a vaginal plug. Body weight, hematocrit, heart weight, hemoglobin concentration, ova recovery rate and fertilization rate were recorded for each female. All morphologically normal embryos collected 24 hours after detection of the vaginal plug were cultured and development in vitro evaluated. Body weight, hemoglobin concentration and hematocrit were lower (P less than .05), and heart weight and percent body weight occupied by the heart (%BWOH) were higher (P less than .05) in mice fed Diet 1. Heart weight and %BWOH were not different among mice fed Diets 2 thru 6 (P greater than .05). Ova recovery rate and fertilization rate were significantly reduced in mice maintained on Diet 1. The incidence of in vitro blastocyst formation was lower in embryos collected from females fed Diets 1 and 3 (P less than .05). Blastocyst hatching in vitro was not observed in embryos from females maintained on Diet 1, and was greater in embryos from females fed Diets 4, 5, and 7 (P less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Taste solution preferences of C57BL/6J and 129X1/SvJ mice: influence of age, sex, and diet

To examine whether age influences taste solution preferences, we measured taste preferences of C57BL/6J and 129X1/SvJ mice given a series of 48-h 2-bottle tests with a choice between water and one of the following taste solutions: 2 mM saccharin, 5 mM citric acid, 30 microM quinine hydrochloride, 75 mM sodium chloride (NaCl), 10 mM inosine monophosphate (IMP), 50 mM calcium chloride (CaCl(2)), and 10% ethanol. We tested separate groups of male mice fed Teklad 8604 chow at ages 4, 6, 9, 12, 15, 20, 25, 30, 40, and 50 weeks and retested some of these mice at 54, 75, and 100 weeks and again at 125 weeks. Female mice fed chow were tested at ages 4, 12, 25, and 50 weeks and retested at 54, 75, 100, and 125 weeks. Male mice fed AIN-93G semisynthetic diet were tested at ages 4, 12, 25, and 50 weeks and retested at 54, 75, and 100 weeks. Concentration-response functions for each taste solution were collected from male and female mice fed chow aged 8 or 125 weeks. In general, the results showed that age had little effect on taste preferences. Exceptions included 1) a small increase in quinine hydrochloride preference between 54 and 125 weeks in mice of both strains and sexes, 2) a marked increase in NaCl preference between 4 and 12 weeks in female B6 mice, 3) a gradual decrease in IMP preference between 4 and 125 weeks in male and female 129 mice, 4) a marked decrease in CaCl(2) preference between 54 and 125 weeks in male and female 129 mice, and 5) a marked reduction in ethanol preference between 4 and 12 weeks in male B6 mice fed AIN-93G diet but not chow. These results show that over a wide range and with the exceptions noted, age contributes little to the variation in taste preferences observed in C57BL/6J and 129X1/SvJ mice.