The specificity of antisera raised by oestradiol-17beta-3-hemisuccinyl-bovine serum albumin.

The preparation of pure oestradiol-17beta-3-hemisuccinyl-bovine serum albumin conjugate is described. Contrary to previous findings this antigen raised reasonably specific antisera in rabbits which possessed a cross reaction of only 2.0% with oestrone, and 0.8% with oestriol. The production of this specific antisera is considered to be due to the high purity of the antigen. The role of the C-3 phenolic hemisuccinyl linkage of the antigen in raising this specific antisera is discussed.

Preparation and antigenic properties of 5alpha-dihydrotestosterone-11-(O-carboxymethyl) oxime-BSA conjugate.

The C-11 (O-carboxymethyl) oxime derivative of 5-alphadihydrotestosterone (5alphaDHT) has been prepared. Due to steric hindrance at C-11, a novel two step procedure was used to introduce the (O-carboxymethyl) oxime at this position. Condensation of this oxime to bovine serum albumin afforded a conjugate which produced anti-5alphaDHT sera inoculated rabbits. Apart from a 30% cross reaction with testosterone, the antisera was reasonably specific for 5alphaDHT.

Ultramicro determination of plasma testosterone by electron-capture detection of testosterone diheptafluorobutyrate.

1. A new highly sensitive and accurate ultramicro method for the estimation of testosterone in human peripheral plasma is described. The method uses paper-and thin-layer-chromatographic separation of plasma testosterone, which is determined as testosterone diheptafluorobutyrate by electron-capture detection after gas-liquid chromatography. 2. The average difference between duplicates is +/-2% (range 1-5%) with as little as 2.5ml. of human male peripheral plasma. With 10ml. of plasma the method is sensitive enough for the accurate determination of testosterone in human female plasma. The high order of accuracy is achieved by the use of a radioactive label and an internal standard for gas chromatography, and by obtaining several gas chromatograms from the same plasma sample. 3. As little as 40mumug. of peripheral plasma testosterone can be detected. The method is 20 times as sensitive as electron-capture techniques with the monochloroacetate derivative. 4. The method is simpler and quicker than double-isotope-derivative methods, and slightly more sensitive. The advantages of the method, which is specific for testosterone, are its high sensitivity and accuracy, which are achieved with relative convenience.

The site of action of 'chlormadinone acetate' (6-chloro-delta 6-dehydro-17 alpha-acetoxyprogesterone) in blocking ovulation in the mated rabbit.

1. In a study of the site of action of a steroid in current use for contraceptive purposes (6-chloro-Delta(6)-dehydro-17alpha-acetoxyprogesterone; ;chlormadinone acetate'), the ovarian responses [secretion rate of 20alpha-hydroxypregn-4-en-3-one (20 alpha-OH), and the occurrence of ovulation] were observed in control oestrous rabbits and in rabbits following mating, injection of luteinizing hormone, and after electrical stimulation of the median eminence.2. Chlormadinone acetate pretreatment (0.5 mg I.V.) did not lower significantly the secretion of 20 alpha-OH in otherwise untreated oestrous rabbits.3. Chlormadinone acetate, given 24 hr before mating, prevented the rise in 20alpha-OH that would otherwise have occurred, and also blocked the ovulation response following mating.4. Chlormadinone acetate pretreatment did not prevent the ovarian responses to administration of luteinizing hormone.5. Chlormadinone acetate pretreatment did not prevent the ovarian responses to electrical stimulation of the median eminence of the tuber cinereum of the hypothalamus.6. The conclusion is drawn that the chlormadinone acetate block of the ovarian responses following mating is at a site in the central nervous system located above the median eminence.