Concentrations of peripheral serum progesterone and prostaglandin F2ƒ¿ (PGF2ƒ¿) in superovulated and normally mated rabbits were determined before and after mating by radioimmunoassay. Multiple vaginal washings were also conducted to recover eggs expelled into the vagina of superovulaed rabbits. The correlation between the fluctuations of progesterone and PGF2ƒ¿ levels and egg transport in superovulated does was discussed. at 120 hours p.c. in superovulated rabbits. During the period of this sharp elevation in progesterone levels, 74.7% of eggs which were recovered from the vagina of superovulated does were obtained. The concentration of PGF2ƒ¿ in superovulated does showed no significant variations before and after injections of PMSG and HCG, and the levels were relatively constant ranging from 0.8 to 3.7 ng/ml. However, the levels of PGF2ƒ¿ in normally ovulated rabbits greatly varied with time, and it was difficult to discuss their trends. It was assumed that the expulsion of a number of eggs in superovulated rabbits into the vagina may be due to the post coital sharp elevation of progesterone levels in blood of superovulated does.
An automated spectrophotometric method, utilizing Technicon AutoAnalyzer modules, has been developed for the analysis of nitrogen in fertilizers. The continuous digestor, which was found to effectively digest organic materials in solution after the reduction step, is coupled with an automated colorimetric system. This colorimetric system employs the ammonia-phenate-hypochlorite reaction. The fertilizer samples are reduced manually via the comprehensive nitrogen method (CNM). The sampling rate chosen is 30 cups/hr (6 reference standards included) which yields an effective analysis rate of 24 samples/hr. The impinger mixer at the exit end of the digestor helix is replaced with a jacketed double-mixing coil and an AO glass fitting for a more stable baseline and improved precision. Manganous ions at a concentration of 5.0 ppm introduced into the color development manifold as a catalyst give a significant increase in sensitivity. When commercial fertilizer samples were analyzed with the automated system, consistently low results were obtained for some samples as compared to results obtained by the AOAC CNM. However, 0.01M potassium sodium tartrate in the color development manifold provides sufficient complexing potential to eliminate the effect of interfering ions. One hundred commercial fertilizer samples including solid, liquid, and suspension fertilizers were analyzed by the Missouri automated nitrogen method. The results agreed well with the results obtained by multiple independent analyses by the AOAC CNM. Details of the automated system, sample preparation, reagent concentrations and preparation, and experimental data are given.
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