Reproduction

doi: 10.1530/jrf.0.0150001-apmid: N/A

Shimizu, H., Toyoda, Y., Takeuchi, S., Kawai, T. & Adachi, S. (1967) Synchronization of oestrus and subsequent fertility of beef cattle following the intravaginal administration of gestagen. J. Reprod. Fert.13, 555.Page 557, Table 1, column 7, lines 4 and 7, the entry should have carried the following footnote: `Sponges dropped on Day 11 and Day 7, respectively, after the insertion' and `(oestrus Day 12)' on line 7 should be deleted.

FLEEGER, J. L.; BISHOP, J. P.; GOMES, W. R.; VanDEMARK, N. L.

doi: 10.1530/jrf.0.0150001pmid: 4384393

Summary.Experiments designed to determine the effects of shortterm unilateral cryptorchidism on testicular lipids have been carried out using twenty-four mature male rabbits. Testes from unoperated control rabbits and rabbits rendered unilaterally cryptorchid for 2, 4 and 6 days were analysed for wet and dry weight, total lipid, total, free and esterified cholesterol, total carboxyl ester, lipid phosphorus and triglyceride.The translocated testes decreased in wet and dry weight (P<0·001) and total lipid content (P<0·001) 6 days after surgery. Lipid concentration increased (P<0·01) in translocated testes, as did concentrations of total cholesterol (P<0·005) and esterified cholesterol (P<0·005). Total carboxyl ester (P<0·001) and triglyceride (P<0·01) concentrations also increased in translocated testes, but lipid phosphorus concentration was unchanged.The contralateral scrotal testes increased in total lipid concentration (P<0·01), esterified cholesterol concentration (P<0·05), total carboxyl ester (P<0·001) and triglyceride (P<0·01) concentrations.

FLEEGER, J. L.; BISHOP, J. P.; GOMES, W. R.; VanDEMARK, N. L.

doi: 10.1530/jrf.0.0150009pmid: 4384394

Summary.Experiments were conducted using twenty-four mature male rabbits to determine the effects of short-term unilateral cryptorchidism on the fatty acid composition of testicular phospholipids and triglycerides.Total lipids were extracted from testes from unoperated control rabbits and from rabbits rendered unilaterally cryptorchid for 2, 4 or 6 days. Phospholipids and triglycerides were separated by thin layer chromatography. The methyl esters of the fatty acids in each fraction were separated and measured using gas-liquid chromatography.The phospholipid fraction was relatively high in the fatty acids palmitate, stearate and oleate whereas the triglyceride fraction contained relatively high levels of oleate, linoleate and palmitate. In the phospholipid fraction of the translocated testes, the proportion of palmitate rose after 2 days (P<0·01), returned to control levels at 4 days, then decreased (P<0·01) 6 days after translocation. Stearate, palmitaldehyde and stearaldehyde concentrations increased (P<0·001) in translocated testes at 4 and 6 days. Concentration of oleate in the phospholipid fraction decreased (P<0·01) after 2 or 4 days and linoleate was lower (P<0·05) than controls after 2 and 6 days of translocation. In the phospholipid fraction of scrotal testes, palmitate percentage increased (P<0·05) at 2 days, and linoleate and stearate decreased (P<0·05) at 2 and 6 days, respectively.Palmitate concentration in the triglyceride fraction of translocated testes increased (P<0·05) at 2 and 6 days as did stearate percentage (P<0·01) after 6 days. Myristate was also higher after 4 days of translocation (P<0·05). A decreased percentage of oleate was found in the triglyceride fraction of 4- and 6-day translocated testes. Triglycerides from the scrotal testes contained higher levels of palmitoleate (P<0·05) and myristate (P<0·05) than unoperated controls, but lesser percentages of stearate (P<0·01).

ORGEBIN-CRIST, M. C.

doi: 10.1530/jrf.0.0150015pmid: 5640752

Summary.In the rabbit, daily sperm production by the testes was estimated by determining the total number of spermatozoa and late spermatids contained in a testicular suspension, and the length of the spermatogenic cycle was estimated by an autoradiographic technique. In twenty bucks, 9 to 14 months old (mean weight 3·9 kg), which had spent 6·9±1·8 weeks in a constant photoperiod of 14 hr light daily, the mean sperm production was 147·4 × 106/day and 1 g of their testicular tissue yielded 26·5 × 106 sperm/day. In another group of thirteen bucks, 15 to 16 months old, which had spent 26·3±1·7 weeks under similar lighting conditions, mean sperm production was 115·8 × 106/day and 1 g of testis yielded 21·4 × 106 sperm/day. The difference between the two groups of animals is highly significant and it is postulated that a constant photoperiod is deleterious for sperm production. In rabbits collected from twice a week the daily sperm output was consistently lower than the testicular sperm production, indicating that slightly more than 50% of the spermatozoa produced are resorbed.

DESJARDINS, C.; KIRTON, K. T.; HAFS, H. D.

doi: 10.1530/jrf.0.0150027pmid: 5640758

Summary.Each of twelve rabbits was ejaculated for 5-week periods at frequencies of: once a week (1 × F) ; four times on Friday (4 × F) ; twice on Monday, Wednesday and Friday (2 × MWF) ; and once daily except Sunday (1×M-S). Average sperm outputs/ejaculate (×106) for the four ejaculation frequencies were: 273 for 1 × F; 114, 207, 141 and 80 for first, second, third and fourth ejaculates, respectively, at 4×F; 78 and 128 for first and second ejaculates, respectively, at 2 × MWF; and 86 for 1 × M-S. Repetitive ejaculation significantly increased weekly sperm output (P<0·01). Component of variance analysis of weekly sperm output indicated that differences among bucks were magnified by the more intensive ejaculation frequencies, but not as much as average sperm output.

EMMENS, C. W.; MILLER, B. G.; OWEN, W. H.

doi: 10.1530/jrf.0.0150033pmid: 5640759

Summary.U-11555A is oestrogenic in vaginal smear tests in mice with a low slope and a subcutaneous med of not less than 5 mg. Its oestrogenic activity intravaginally was not fully investigated, but is not high. It is weakly anti-oestrogenic in similar tests, with an med against oestradiol of about 200 μg subcutaneously, perhaps a little lower intravaginally. No interactions were seen as they were with U-11100A† (Emmens & Martin, 1965).U-11555A has an antifertility action in the mouse when injected on Days 1 to 3 or 4 to 6 of pregnancy, with meds of about 100 μg (Days 1 to 3) and 300μg (Days 4 to 6). In rats, U-11555A has a constant subcutaneous or oral med on Days 1 to 3 or 4 to 6 of about 400 μg. In simultaneous tests in rats, U-11100A had meds of about 20 μg (Days 1 to 3) and 60 μg (Days 4 to 6) and was significantly more potent orally than by injection.From these results, the antifertility action of U-11555A can hardly be attributed to oestrogenic properties, as was that of U-11100A by Emmens & Martin (1965), and its action profile is not very similar to that of the latter. Its antifertility action in mice is in accord with its anti-oestrogenic potency in that species.

SCHWARTZ, NEENA B.; TALLEY, WILLIAM L.

doi: 10.1530/jrf.0.0150039pmid: 5640760

Summary.Daily measurements of pituitary lh content during pregnancy in the rat, by the ovarian ascorbic acid depletion method, reveal no evidence of the regular changes manifested during the non-pregnant oestrous cycle. Instead, lh content rises from typical oestrous values on Day 1 to levels characteristic of cyclic pro-oestrus on Day 8. Pituitary lh content then exceeds pro-oestrous levels throughout the remainder of pregnancy until Day 21. Ovarian weight first decreases up to Day 10, then rises until the end of pregnancy. Ovarian histology reveals the presence of follicles of all sizes on each day, accompanied by increasing size of the corpora lutea of pregnancy. The significance of these observations and previous data in the literature concerning the pituitaryovarian axis during pregnancy are discussed from the point of view of the question of persistence of some manifestations of the oestrous cycle during pregnancy.

HÅSTEIN, TORE; VELLE, WEIERT

doi: 10.1530/jrf.0.0150047pmid: 5640761

Summary.Bovine placental aldose reductase has been partially purified from foetal cotyledons and the levels of activity measured in forty samples from foetuses 1 to 9 months old. A statistically significant increase in the specific activity of the enzyme with advancing pregnancy was observed.No significant correlation was found between aldose reductase activity and foetal blood fructose levels.The increase in enzyme activity during pregnancy followed a pattern similar to that previously observed for urinary oestrogens in cows.

DUNCAN, G. W.; WYNGARDEN, L. J.; CORNETTE, J. C.

doi: 10.1530/jrf.0.0150053pmid: 5640762

Summary.The effect of nafoxidine HCl and oestradiol on progesterone and oestradiol uptake by rat deciduomata was studied. Rats were ovariectomized and their uteri traumatized; they were subsequently injected for 4 days with 1·5 mg of progesterone and either oestradiol (0·005, 0·05, 0·1, 0·5 or 1·0 μg), or oestradiol (0·05 μg) and nafoxidine HCl (0·5, 5, 50, 500, 1000μg). Tritiated oestradiol or progesterone was injected 4 hr before killing the rats on the last day of treatment.Uterine horns (traumatized and contralateral non-traumatized cornua) were removed and immediately prepared for the determination of radio-activity. Total non-volatile radio-activity and the radio-activity associated with the protein, ether-soluble and water-soluble fractions were determined. Ether soluble fractions were chromatographed on silica gel; areas associated with major steroid components were isolated and counted for radio-activity.Both nafoxidine HCl and oestradiol effectively suppress the deciduomata response. The effects of each compound on the above parameters are not comparable in all cases. These differences, and their significance, are discussed.

GUNN, SAMUEL A.; GOULD, THELMA CLARK; ANDERSON, W. A. D.

doi: 10.1530/jrf.0.0150065pmid: 5640763

Summary.It is known that the selective injurious effect of cadmium on the testis can be prevented by zinc, cysteine or selenium. Studies, conducted in CD-1 mice, were initiated to determine whether any of these treatments offered protection by preventing cadmium from reaching the testis in doses sufficient to cause injury. Using cadmium chloride, labelled with 109Cd, it was shown that none of these protective agents decreased the amount of cadmium reaching the testis. Zinc acetate evoked no significant changes, cysteine brought about a slight enhancement of cadmium level but selenium dioxide produced a marked and prolonged elevation of cadmium uptake by the testis. Comparable studies in which selenium, rather than cadmium, was labelled (75Se) demonstrated that, in the presence of cadmium, selenium levels were augmented. Possible mechanisms are discussed to explain the diverse means of protection offered by zinc, cysteine and selenium. Since the site of cadmium-induced testicular injury has been pin-pointed at its vasculature, it is suggested that these protective agents exert their action at the vascular level.