Effect of exogenous insulin administration on ovarian function, embryo/fetal development during pregnancy in goats.

The effect of insulin was investigated on ovarian follicle population, ovulation rate, hormonal profiles and embryo/fetal development during pregnancy using transrectal ultrasonography in goats. Twelve goats synchronized in estrus were selected for the experiment. They were divided into two groups, viz. (untreated control, n=6) and (insulin treated, n=6). In treated group long acting bovine insulin was administered @ 0.2IU/kg body weight subcutaneously for three consecutive days, i.e. days 7-9 of estrous cycle. Thereafter, weekly single injection of insulin was continued for rest of the experiment. However, in control group only normal saline was injected as placebo. Breeding was allowed by natural service in both the groups. The does were subjected to B-mode transrectal ultrasound scanning of ovary and uterus weekly up to 120 and 98 days of gestation, respectively. Blood samples were collected weekly up to 135 days of gestation for the estimation of estradiol 17beta and progesterone (P4). The result revealed no difference in mean number of total follicles between the control and insulin treated groups. The diameter of medium follicle did not differ where as diameter of large follicle was comparatively higher in treated than control goats. The average number of corpus luteum (CL) was higher in insulin treated group as compared to control (1.66 vs. 1.16). However, the number as well as mean diameter of CL did not differ significantly between treated and control group. Serum concentrations of estradiol 17beta and progesterone were significantly (P<0.01) higher in treated than control goats. Embryonic vesicle was detected by day 21 in both the groups, however, its diameter did not differ significantly (0.73 and 0.72cm) between the groups. The twinning percentage was higher (50 vs. 16%) in insulin treated than the control goats. Placentome diameter was also higher (P>0.05) in treated animals. The results demonstrated beneficial effect of exogenous administration of insulin on ovarian function and twinning percentage in goats.

Fertility responses and hormonal profiles in repeat breeding cows treated with insulin.

The influence of insulin treatment on conception rate and endocrine profile was studied on 21 repeat breeding cows divided randomly into two groups, i.e. insulin treatment (n = 11) and control (n = 10). Cows of the insulin treatment group were injected subcutaneously with a long acting purified form of bovine insulin at 0.2 IU/kg body weight/day on days 8, 9 and 10, and then with 0.75 mg tiaprost (PGF(2)alpha) intramuscularly on day 12 of the oestrous cycle (oestrus = day 0). The cows of the control group only received 0.75 mg tiaprost was injected intramuscularly on day 12. There was no difference (P > 0.05) in the interval to the onset of oestrus and subsequent cycle length between the treatment (84.5 +/- 6.6 h and 21.2 +/- 0.6 days, respectively) and the control (72.3 +/- 5.9 h and 19.7 +/- 0.4 days, respectively) groups. First service conception rate and overall pregnancy rate did not differ (P > 0.05) between the insulin treatment group (45.4 and 63.6%) and the control group (33.3 and 40.0%). Progesterone concentration following administration of insulin increased (P < 0.05) in the insulin treated cows (2.2+/-0.4 ng/ml versus 2.9 +/- 0.4 ng/ml) but the concentration of oestradiol-17beta did not differ. The insulin concentration was higher on day 10 of the oestrous cycle (P < 0.05) in the treatment group (71.0 +/- 12.5 microU/ml versus 38.1 +/- 4.5 microU/ml). The insulin and glucose concentrations were higher (P > 0.05) in animals, which subsequently became pregnant than in non-pregnant animals. The results may indicate that there is beneficial effect of insulin on fertility in repeat breeder cattle.

A reactive analytical approach for the estimation of olefinic content in gasoline-range hydrocarbons by gas chromatography.

The estimation of olefinic content in conversion processes such as the etherification of olefins in fluid catalytic cracking (FCC) gasoline is essentially required. Gas chromatography (GC) is the well-established method for the quantitative analysis of olefins in etherification processes. The current state-of-the-art GC methods employing highly specific long single capillary columns such as Petrocol-DH are being used for the analysis of gasoline-range hydrocarbons. However, the method needs many standard reference samples of respective components in a complex mixture of hydrocarbons, which limits the scope of the analytical method. The alternative approach followed by this investigation is based on the reactive method of the analysis of olefins in FCC light gasoline by subjecting them to hydrogenation and estimating the olefinic content by GC comparing the gas chromatograms of the original feed and hydrogenated product using a Petrocol-DH column. A decrease in the quantity and disappearances of the peaks are assumed as olefins, and their number and total composition is calculated. In this study the bromine number method is used to estimate the olefinic content for a comparison of results with the adopted proposed methodology. The adopted methodology quantitates olefinic content in FCC light gasoline, which is comparable with reported literature values and the bromine number method. With the availability of standard reference samples of some important major reactive olefins, the adopted methodology can also give component-wise analysis as well as total olefinic content in a single step in processes such as etherification. The methodology can be also useful in reactions in which the conversion of total olefinic content is needed such as hydration, esterification, and alkylation of olefins in a complex mixture of hydrocarbons apart from the etherification of olefins in FCC gasoline.

Involvement of iron and free radicals in benzene toxicity.

The 59Fe distribution after a single i.v. injection of 59Fe citrate in rats exposed to benzene was studied in circulating erythrocytes and organs up to period of 1 hr to 14 days. The iron content was significantly higher in bone marrow and liver compared to a control group of animals. A few cells with hemosiderin granules were observed in the benzene-administered group. Benzene increased lipid peroxidation in the liver and bone marrow and iron accelerated it further. Superoxide dismutase activities measured in terms of epinephrine auto-oxidation, an indirect measure of superoxide anion generation was enhanced in the benzene-treated groups. The data suggest the involvement of oxygen activation in benzene toxicity.