[The anti-rubella immune state of the adult female population of Local Health Unit 26 of the Piedmont Region. Prospects for a vaccination campaign]

500 serum samples were collected from women in child-bearing age and tested for HI titer against rubella virus. 6.8% had no protective level, that is less than 1/32. A vaccination program is discussed.

Effect of photoperiod and gonadectomy on testosterone metabolism in vitro by the prostate of the golden hamster

Testosterone metabolism was studied in vitro in the prostate of intact and castrated golden hamsters maintained either in short days (8 h light: 16 h darkness, 8L: 16D) or in long days (14L: 10D). Testosterone was found to be converted into 17 beta-hydroxy-5 alpha-androstan-3-one (5 alpha-DHT), 5 alpha-androstane-3 alpha, 17 beta-diol, 5 alpha-androstane-3, 17-dione and androstenedione. The mean conversion of testosterone to 5 alpha-DHT was higher in prostates from animals maintained in long days than in short days (P less than 0.0025) while that to androstenedione was higher in short days (P less than 0.0005); no significant changes in the formation of the other three metabolites were noted. Castration of animals maintained in short days resulted in a significant (P less than 0.05) decrease in the mean conversion to all four metabolites. In contrast, castration of animals kept in a long-day regime caused a significant (P less than 0.01) decrease in the mean formation of 5 alpha-DHT but a significant (P less than 0.05) increase in the mean formation of 5 alpha-androstane-3 alpha, 17 beta-diol.

Effect of corticosterone on the hypothalamic-pituitary-gonadal system of male Japanese quail exposed to either short or long photoperiods

Male quail were bred under short photoperiods of 8 h light: 16 h darkness (8L : 16D; SD) for the first 4 weeks of life and were then transferred to either long photoperiods of 16L : 8D (LD) or maintained under the SD regime. Both groups of birds were treated for 2 weeks with a daily dose of either 0·25 or 1·0 mg corticosterone. The conversion of [14C]testosterone in vitro into 5α- and 5β-dihydrotestosterone (5α- and 5β-DHT), 5α- and 5β-androstane-3α,17β-diol, and androstenedione was then measured in the pituitary and cloacal glands of all birds. In the hyperstriatum and posterior hypothalamus only 5β-reduced metabolites and androstenedione were detected.

Transfer to LD and injection of corticosterone affected the metabolism of testosterone only in the pituitary and cloacal glands. In the pituitary gland, exposure to LD increased the production of 5α-reduced metabolites but not of either 5β-reduced metabolites or androstenedione. In both SD and LD birds, injections of corticosterone enhanced the production of 5β-reduced steroids and decreased the production of androstenedione. In LD birds corticosterone also decreased the production of 5α-androstane-3α,17β-diol. Plasma levels of LH and FSH were higher in the LD than in the SD birds. In the SD birds treatment with corticosterone increased the level of LH after 14 days of treatment. Exposure to LD decreased the production of 5β-androstane-3α,17β-diol and androstenedione in the cloacal gland and increased the conversion of testosterone into 5α-DHT Treatment with corticosterone increased the production of androstenedione in the cloacal gland of LD birds but decreased it in that of SD birds. Corticosterone also partially blocked the photoinduced growth of the cloacal gland, but it slightly stimulated the growth of the gland in the SD birds. After 2 weeks of treatment SD (but not LD) corticosterone-treated birds had higher testicular weights than the corresponding controls.

It is suggested that treatment with corticosterone might affect the hypothalamic-pituitary-gonadal axis partly through changes in the metabolism of testosterone.

Conversion of testosterone to 5 beta-reduced metabolites in the neuroendocrine tissues of the maturing cockerel

The metabolism in vitro of [4-14C]testosterone to reduced derivatives was studied in the pituitary gland, hypothalamus and hyperstriatum dorsale of cockerels from hatch to sexual maturity. The most important metabolites were 5 beta-dihydrotestosterone (5 beta-DHT), 5 beta-androstane-3 alpha, 17 beta-diol (5 beta-3 alpha-diol) and 5 beta-androstane-3 beta, 17 beta-diol. Trace amounts of androstenedione and, in the hypothalamus only, of 5 alpha-DHT were also detected. The amounts of 5 beta-reduced metabolites produced by all neuroendocrine tissues declined progressively during maturation with the steepest fall occurring during the first 2 weeks after hatch. At all ages studied, 5 beta-DHT was formed to the greatest extent by the hyperstriatum dorsale, to a lesser extent by the hypothalamus and in the smallest quantities by the pituitary gland. In the three tissues studied, 5 beta-3 alpha-diol tended to be formed to the greatest extent by the pituitary gland. No significant change was observed in the metabolism of testosterone to reduced derivatives in any of the neuroendocrine tissues after castration. It was concluded that in the cockerel, unlike the rat, a change in 5 alpha-reductase activity of the neuroendocrine tissues is unlikely to be involved in the initiation of puberty. The physiological significance of 5 beta-reductase activity in the neuroendocrine tissues remains to be established.

Conversion of progesterone to 5 alpha- and 5 beta-reduced metabolites in the hen and its potential role in the induction of the preovulatory release of luteinizing hormone

In the laying hen, progesterone was shown to be converted in vitro in the pituitary gland and the hypothalamus to 5 beta-pregnane-3,20-dione (5 beta-pregnane-3 alpha-ol-20-one (5 beta,3 alpha-ol) and 5 alpha-pregnane-3,20-dione (5 alpha-DHP) and in the hyperstriatum dorsale to 5 beta-DHP and 5 beta,3 alpha-ol. The conversion of progesterone to 5 beta-reduced metabolites was greater in the hyperstriatum dorsale than in the hypothalamus (P < 0.001) and greater in the hypothalamus than in the pituitary gland (P < 0.01). The conversion of progesterone to 5 beta-reduced metabolites was greater than its conversion to 5 alpha-DHP in the pituitary gland (P < 0.01) and the hypothalamus (P < 0.001). The possibility was investigated that 5 alpha-DHP and 5 beta-DHP may act as metabolic intermediaries in the mechanism by which progesterone exerts a positive feedback effect on LH release. Progesterone, 5 alpha-DHP and 5 beta-DHP were injected into laying hens at doses of 0.05, 0.25 and 1.25 mg/kg and the changes in the concentration of plasma LH were followed for 4 h thereafter. Secretion of LH was stimulated after treatment with progesterone or 5 alpha-DHP but not 5 beta-DHP. Progesterone stimulated Lh release more effectively than did 5 alpha-DHP, since an increase in the concentration of plasma LH was observed after 0.25 mg progesterone/kg but not after the same dose of 5 alpha-DHP. It was concluded that in the hen 5 alpa-DHP is unlikely to play a role in the induction of the preovulatory release of LH.

Cloacal gland of the Japanese quail: androgen dependence and metabolism of testosterone

A cloacal gland complex whose growth and development is androgen-dependent exists in the Japanese quail. In-vitro incubation studies of the cloacal gland using 4-14C-labelled testosterone as substrate allowed the positive identification of five metabolites: androstenedione, 5 beta-dihydrotestosterone (5 beta-DHT), 5 beta-androstane-3 alpha, 17 beta-diol, 5 alpha-DHT and 5 alpha -androstane-3 alpha, 17 beta-diol. More polar metabolites, not yet chemically identified, were detected in trace amounts. Androstenedione appeared to be the main testosterone metabolite in immature birds while in mature birds on long daylengths testosterone was preferentially metabolized to 5 alpha-DHT. This change may have been in response to the higher levels of plasma steroids found in mature birds. When various testosterone metabolites, contained in silicone elastomer capsules, were implanted s.c. into castrated birds maintained on a photostimulatory light regime, 5 alpha-DHT, 5 alpha-androstane-3,17-dione, androstenedione and 5 alpha-androstan-3 alpha-ol-17-one were shown to be equipotent with testosterone in stimulating the development of the cloacal gland. 5 alpha-Androstane-3 alpha, 17 beta-diol and 5 alpha-androstan-3 beta-ol-17-one stimulated some growth while 5 beta-DHT, 5 alpha-androstane-3 beta, 17 beta-diol, 5 alpha-androstane-3 alpha, 17 beta-diol, 5 beta-androstane-3,17-dione, androst-5-en-3 beta-ol-17-one and androst-5-ene-3 beta, 17 beta-diol were completely ineffective.

Role of testosterone and of its metabolites in regulating gonadotrophin secretion in the Japanese quail

In the Japanese quail gonadal steroids can depress plasma levels of LH and FSH. Since it is now accepted that testosterone metabolites may be metabolized to the tissue-active forms of the hormone, the in-vitro tissue incubation has been combined with steroid replaement therapy in vivo to investigate the physiological roles of various testosterone metabolites as inhibitory feedback agents on gonadtorophin secretion in quail. After the incubation of quail pituitary glands for 3 h with labelled testosterone four metabolites could be identified; androst-4-ene-3,17-dione, 5 beta-dihydrotestosterone (5 beta-DHT), 5 beta-androstane-3 alpha, 17 beta-diol and 5 alpha-DHT. No 5 alpha-androstane-3 alpha, 17 beta-diol was found. Quantitatively, androstenedione was the major metabolite and converison of testosterone to 5 beta-metabolites was significantly greater than to 5 alpha-androgens. Hypothalamic and hyperstriatal tissues converted testosterone than to 5 alpha-androgens. Hypothalamic and hyperstriatal tissues converted testosterone to androstendione, 5 beta-DHT and 5 beta-androstane-3 alpha, 17 beta-diol but not to 5 alpha-DHT or 5 alpha-androstane-3 alpha, 17 beta-diol. Gonadotrophin secretion was studied in castrated quail after chronic s.c. implantation of steroid-containing silicone elastomer capsules or acute injection i.m. of steroid in ethanol: saline. Irrespecive of the route of administration seven androgens, listed in descending order of potency, reduced the increased levels of plasma LH: testosterone: 5 alpha-DHT; androstenedione; 5 alpha-androstane-3, 17-dione; 5 alpha-androstane-3 alpha, 17 beta-diol; 5 alpha-androstan-3 alpha-ol-17-one; 5 alpha-androstan-3 beta-ol-17-one. No changes in levels of plasma LH were observed after the administration of 5 beta-DHT, 5 alpha-androstane-3 beta,17 beta-diol, 5 beta-androstante-3 alpha, 17 beta-diol, 5 beta-androstane-3, 17-dione, androst-5-ene-3 beta, 17 beta-diol or androst-5-en-3 beta-ol-17-one. Testosterone and oestradiol-17 beta were effective in inhibiting secretion of both LH and FSH in young photostimulated quail and completely blocked testicular growth: 5 alpha-DHT inhibited only the release of LH and testicular growth was unaffected.

Androgen dependence of rat prostatic 3alpha-hydroxysteroid dehydrogenase

Department of Endocrinology, University of Milan, Via A. del Sarto 21, 20129 Milan, Italy

(Received 8 May 1978)

It is well established that the rat prostate gland converts testosterone mainly into 5α-androstan-17β-ol-3-one (5α-dihydrotestosterone, 5α-DHT) and to a lesser extent into 5α-androstan-3α,17β-diol (5α-tetrahydrotestosterone, 5α-THT). This occurs, both in vivo and in vitro, through the action of a 5α-reductase and a 3α-hydroxysteroid dehydrogenase system (Baulieu, Lasnitzki & Robel, 1968; Bruchovsky & Wilson, 1968; Gloyna & Wilson, 1969; Kniewald, Massa & Martini, 1971). It has also been recognized that, although the 5α-reduction of testosterone is an irreversible reaction, the reduction of 5α-DHT to 5α-THT is reversible (Becker, Grabosch, Hoffmann & Voigt, 1973; Cresti & Massa, 1977). Consequently, the question has been raised as to whether the biological actions of 5α-THT are attributable to the compound as such or to 5α-DHT. At the anterior pituitary level, 5α-reductase activity is increased by castration and decreased

Xenon-133 muscular flow measurements in surgery for arterial disease of the lower limbs

Muscular flow measurements were carried out in 34 patients with peripheral chronic arterial occlusive disease using the 133-xenon clearance method. The reactive hyperemia technique was preferred to the walking test. All the patients were investigated by angiography and 46 limbs were available for assessment. Control flow measurements were done after treatment in the following groups: arterial reconstruction in ten limbs of nine patients, unilateral lumbar sympathectomy in three and medical therapy in seven. Follow-up was from three to 12 months. The findings of flow measurements were of limited value in identifying the distribution of the arterial disease, but they provided a reliable means to predict the results of direct arterial repair in various procedures. They also proved to be a valuable method to assess the results of surgery. This does not seem to apply to lumbar sympathectomy or conservative treatment.

Effects of prolactin on LH release in male rats

Normal and castrated male rats were injected subcutaneously (s.c.) with a homologous preparation of prolactin (Prl) for 4 1/2 days, and serum levels of LH and FSH were measured at the end of the treatment. LH was undetectable in normal animals, injected either with Prl or with the vehicle. The treatment produced a significant reduction of the levels of LH in the castrated animals. No effect on FSH levels could be observed in either the normal or the castrated animals. The only relevant autopsy finding was a reduction of pituitary weight in normal animals treated with Prl. No effect on the weight of the testes or of the sex accessories was observed. It is suggested that Prl may directly interfere with the central mechanisms which control LH secretion.

Metabolism of testosterone in the anterior pituitary gland and the central nervous system of the European starling (Sturnus vulgaris)

The metabolism of testosterone was studied in vitro in anterior pituitary, hypothalamic and hyperstriatal tissues taken from male European starlings in the autumn. In all the tissues studied, testosterone was converted into 5alpha-androstan-17beta-ol-3-one (5alpha-DHT), 5beta-androstan-17beta-ol-3-one (5beta-DHT), 5beta-androstane-3alpha,17beta-diol (5beta-THT), 5beta-androstane-3,-17-dione and androst-4-ene-3,17-dione. The 5alpha-DHT was produced in significantly greater amounts by the pituitary gland than by the hypothalamus and hyperstriatum. The amount of 5alpha-DHT produced, however, was very low in comparison with the amounts of 5beta-reduced metabolites. The amount of 5beta-reductase was also higher in the pituitary gland than in the two nervous tissues. The ratios between the production of 5beta-DHT, 5beta-THT and 5beta-androstane-3,17-dione were, however, different in the three tissues: 5beta-DHT was produced in the greatest quantities by the hyperstriatum, while the production of 5beta-THT, 5beta-androstane-3,17-dione and androst-4-ene-3,17-dione was greatest in pituitary tissue. The role of 5alpha- and 5beta-reduced metabolites in the pituitary gland and in the brain of birds is unknown, but some possibilities arising from the present results are discussed.