Plasma concentrations for several androgens and estrogens were determined in male domestic pigs from birth to eight months of age. Samples (N = 6) of blood were collected from Yorkshire males at weekly intervals from birth to four weeks, and thereafter at monthly intervals to eight months. Radioimmunoassays were done without extraction from plasma for dehydroepiandrosterone sulphate, androstenedione and estrone sulphate. Other steroids were measured after solid-phase extraction, separate elution of unconjugated and conjugated fractions, and solvolysis of sulpho-conjugated steroids (testosterone, 5α-androstane-3β, 1 7β-diol, epiandrosterone, 19-nortestosterone and estradiol-177β). All steroids showed a peak in plasma levels at 2–4 weeks after birth. Concentrations remained low from 2–5 months and rose markedly thereafter. Most steroids were present in much greater quantities as sulpho-conjugated compounds. Concentrations of testosterone sulphate and testosterone were similar (9.4 μmol/l) at three weeks but the sulphated form predominated after six months of age. This study shows that during postnatal development the testes of the domestic pig are remarkably active in steroidogenesis with a peak at 2–4 weeks after birth. Also, the range of steroid products seen at this stage is comparable to that shown by the mature boar.

An extraction and assay procedure to measure fecal estradiol-17p and progestin concentrations in several cat species was developed and validated for use for noninvasive monitoring of ovarian function. Fecal samples were collected over a range of 3-20 months from female tigers (three), lions (three), snow leopards (three), cheetahs (two), caracals (two), and domestic cats (five). Samples were extracted with 90% methanol, lipids removed with petroleum ether, and the estradiol and progestins in the methanol measured by radioimmunoassay (RIA). High Performance Liquid Chromatography (HPLC) fractionation and subsequent RIA of the fractions indicated that the estradiol-17p antiserum cross-reacted primarily with estradiol-17P in the feces of lions and tigers and was assumed to be specific for estradiol-17P in the feces of other species as well. However, there were several immunoreactive compounds, presumably progesterone metabolites, excreted in the feces which varied both quantitatively and qualitatively among species. The behavior of tigers, lions, cheetahs, and caracals was visually monitored during the collection period and frequency of sexual behaviors was positively correlated with increases in fecal estradiol in all species observed. The mean fecal estradiol-17P peaks were as follows: tigers, 128.0 t 13.1; lions, 186.0 5 14.8; snow leopards, 136.7 k 15.9; cheetahs, 140.9 k 9.0; caracals, 24.5 ? 4.0; and domestic cats 158.9 2 19.3 ng/gm. Fecal progestin concentrations rose significantly (P < 0.001) only after breeding or during pregnancy and were as follows: tigers, 5.6 t 0.6; lions, 1.9 t 0.1; cheetahs, 8.4 5 1.1; and caracals, 2.4 5 0.4 pg/gm. Fecal progestins were elevated for one-half to twothirds of the gestation length during presumed pseudopregnancy but remained elevated throughout successful pregnancies. These results suggest that ovarian function can be monitored noninvasively in the family Felidae by the measurement of fecal estradiol-17P and progestin concentrations 0 1995 Wiley-Liss, Inc.

No abstract

Because estradiol (E(2)) production by the early equine conceptus is considered crucial to the establishment of pregnancy, the amounts of E(2), estrone (E(1)), and their sulfates (E(2)S, E(1)S) were measured by RIA in yolk-sac fluid of 63 conceptuses collected by transcervical lavage over the period of 11-26 days after ovulation. Amounts increased significantly with age of conceptus, especially for E(1)S. Then, the metabolism of E(2), which may be highly relevant for its action, was examined in the conceptus and endometrium over the period when the conceptus ceases to migrate within the uterus. Eleven conceptuses collected mainly on Days 12, 15, and 18, with endometrial biopsy samples taken immediately thereafter, were used for steroid metabolic studies. Trophoblastic and endometrial tissues were incubated with [(3)H]-labeled E(2) or E(1), and with [(14)C]-E(1) in one experiment. Steroids were recovered from the media by solid-phase extraction (SPE) and eluted separately as unconjugated and conjugated fractions. Conjugation increased from Day 12 for the trophoblast (more so by bilaminar than trilaminar tissues on Day 18) and was much greater for endometrium, with almost all as sulfoconjugates. HPLC profiles of free and sulfate fractions were obtained from a gradient of acetonitrile/water. Interconversion (E(2) right harpoon over left harpoon E(1)) by trophoblast varied with development; it favored E(2) in older conceptuses, more in bilaminar than trilaminar tissues. Some more polar products were also noted, with loss of tritium seen as [(3)H](2)O at SPE, and confirmed by HPLC in a second system with authentic reference steroids. Almost all radioactivity in the endometrium was present as E(2) in both free and sulfate fractions. It was concluded that local metabolism of E(2) is quantitatively significant and may play an important role in the actions of the large amounts of estradiol produced by the early equine conceptus.

No abstract

The effects of oestrogens on the activity of accessory sex glands were studied in castrated boars receiving testosterone continuously. Diethylstilboestrol (DES), 17\g=b\-oestradiol(E2) and oestrone (E1) were administered successively for 6-week periods which alternated with treatments of testosterone alone. Semen was collected twice each week and measurements were made of the total, the strained and the gel volumes. Citric acid and fructose contents of the seminal plasma were also determined. Highly significant (P<0\m=.\01) differences between boars were observed for all criteria in a series of collections made before castration.Castration resulted in reduction in the total quantities of secretory products of the accessory sex glands. Subsequent treatment with testosterone alone for a period of 12 weeks had only a slight effect on their secretions. Supplementary treatment with DES, E2 or E1 significantly (P<0\m=.\01) increased the secretory activity of these glands from the levels in the respective preceding periods with testosterone alone. After withdrawal of oestrogens, the elevated levels of citric acid secretion remained high or increased further, while the amounts of seminal plasma and fructose continued at the higher levels or declined.Oestrogens also had a synergistic effect with testosterone on improving the libido of castrated boars. The reaction time was decreased by 45% (P<0\m=.\01)during supplementary treatment with oestrone for 12 weeks.The results of these experiments suggest that oestrogens act synergistically with testosterone on the accessory sex glands and on the sexual behaviour of the boar.

Breeding soundness evaluation (BSE) is the primary assessment for determining the reproductive potential of male animals. This method, however, cannot be used to evaluate semen frequently or to predict future semen quality. Computerized analysis of ultrasonographic images provides information on histophysiological changes in male reproductive organs. We hypothesized that: (i) semen parameters would correlate with ultrasonographic characteristics of the distal region (cauda) of the epididymis and (ii) testicular ultrasound images and/or circulating testosterone concentration would predict future semen quality in the ram. Six adult rams underwent BSE and scrotal ultrasonography approximately 60 d apart (average duration of the spermatogenic cycle) both during the breeding (December and February) and non-breeding (June and August) seasons. An inverse correlation was found between pixel intensity (numerical pixel values) of the epididymes and percentage of sperm in semen with normal morphology (r = -0.46, P < 0.05). Pixel heterogeneity (standard deviation of pixel values) correlated negatively with percentage of sperm with normal morphology (r = -0.42, P < 0.05) and directly with percentage of spermatozoa with abnormal tails (r = 0.43, P < 0.05). Pixel heterogeneity of testicular parenchyma obtained approximately 60 d prior to semen evaluation inversely correlated with percentage of sperm with normal morphology (r = -0.73, P < 0.01) and sperm progressive motility (r = -0.76, P < 0.01), and directly with percentage of sperm with abnormal tails (r = 0.72, P < 0.01) and loose heads (r = 0.79, P < 0.01). We concluded that scrotal ultrasonography combined with computer-assisted analyses of epididymal and testicular echotexture in the ram was a valuable method for determining certain current and future semen parameters, respectively.

A method is described for the extraction and purification of estrogen sulfates from testicular tissues. By use of this method estrone 3-sulfate and estradiol-17β 3-sulfate were isolated from stallion testes and identified by infrared spectroscopy. Further characterization was effected by the use of estrone-4-14C and estrone-6,7-3H 3-sulfate as standards for chromatographic comparison. Preliminary results indicated that the amounts of the estrogens present as sulfates were greatly in excess of the amounts present as free steroid. Estradiol-17α could not be detected.