doi: 10.1530/jrf.0.0190001pmid: N/A
"FOREWORD HERBERT McLEAN EVANS" published on Jun 1969 by Bioscientifica Ltd.
doi: 10.1530/jrf.0.0190003pmid: N/A
"Dr HERBERT M. EVANS" published on Jun 1969 by Bioscientifica Ltd.
doi: 10.1530/jrf.0.0190051pmid: 5793914
Summary.Embryo attachment and implantation in the ewe have been examined with a view to (a) elucidating the interrelationships of the trophoblast and the uterine epithelium, and (b) defining accurately the time relationships of the various phenomena. Embryonic attachment occurred during the 15th day of pregnancy and cytological changes within the uterine caruncular epithelium that appeared on the following day and were completed within a week, resulted in the formation of plaques of multinucleate symplasm and the death of some maternal epithelial cells.High levels of acid phosphatase activity, considered to demonstrate the release of lysosomal hydrolases, were associated with the modification of the maternal epithelium and with the later trophoblastic invasion of the uterine stroma. Alkaline phosphatase activity present in the apical cell membranes of the opposing trophoblast and uterine epithelium is considered to be associated with carbohydrate metabolism and the production of trophoblastic fibrinoid.No evidence was obtained to support proposals that trophoblastic binucleate giant cells have a major role in modifying the uterine epithelium through their phagocytic activity or as a source of the cryptal epithelium. The cryptal epithelium during the first 6 weeks of pregnancy appears to be derived from the symplasmic plaques of maternal epithelium.
doi: 10.1530/jrf.0.0190063pmid: 5793915
Summary.The effect on spermatogenesis of intratesticular and subcutaneous immunization with genital tract fluids of bulls was studied in sexually mature guinea-pigs, rabbits and sheep.Immunization with bovine seminal vesicle fluid produced a decrease in the index weight of the testes, a disturbance of spermatogenesis and, in more severe cases, a distortion and contraction of the seminiferous tubules. In all animals immunized subcutaneously, identical circulating antibodies were found in animals with damaged testes and in animals with normal testes. They did not cause spermagglutination, immobilization or spermatotoxic reactions. No circulating antibodies could be found in guinea-pigs and rabbits immunized by a single intratesticular injection.
QUINLIVAN, T. D.; ROBINSON, T. J.
doi: 10.1530/jrf.0.0190073pmid: 4183293
Summary.An experiment is described in which spermatozoa were recovered from genital tracts of ewes either at the first oestrus following progestagen synchronization or at a normal oestrus.Recoveries 1, 12, 24, 36 and 48 hr after the insemination of 500× 106 spermatozoa show that synchronization with intravaginal sponges impregnated with the synthetic progestagen 17α-acetoxy-9α-fluoro-11β-hydroxypregn-4-ene-3,20-dione (Cronolone, Searle) alters the numbers and distribution of spermatozoa throughout the female genital tract at the first oestrus after treatment.One hour after insemination the total numbers of spermatozoa recovered, and their distribution between the various regions of the tract, differed little between progestagen-treated and untreated ewes. Thereafter the numbers recovered from treated ewes were significantly fewer than from untreated, and their distribution differed. Significant differences appeared in the vagina at 12 hr and in the cervix and uterus at 24 hr and thereafter this difference was maintained. The pattern in the Fallopian tubes followed that of the uterus. At 24 hr the mean numbers of tubal spermatozoa recovered were: synchronized—900; non-synchronized—8200 (P< 0·001).Both transport and survival of spermatozoa may be deleteriously affected in the reproductive tract of the progestagen-treated ewe.
doi: 10.1530/jrf.0.0190087pmid: 5793916
Summary.A series of six factorial experiments is described in which ovaries of 15-day-old mice were cultured in vitro for 2 to 4 days in the presence of various concentrations of highly purified fsh and lh. The uptake of [14C]thymidine by the tissue was measured in all experiments. fsh consistently and significantly increased the uptake where the mice used were above a certain size. In only two experiments did lh significantly increase thymidine uptake; this effect appeared to depend on certain precise conditions of culture. The uptake of [3H]lysine was also measured in two of the six experiments; it was significantly increased by fsh in one of them. lh had no significant effect on lysine uptake. There were no significant interactions between fsh and lh. It is concluded that the uptake of labelled thymidine in response to fsh should have useful experimental applications. The possibility that the exclusive role of fsh is to initiate DNA synthesis in follicle cells is briefly discussed.
JOHNSON, L. A.; GERRITS, R. J.; YOUNG, E. P.
doi: 10.1530/jrf.0.0190095pmid: 5793917
Summary.Sixty-four ejaculates were collected from four crossbred litter-mate boars. Two frequencies of ejaculation were employed; once every 3 days and daily. Total semen volume (ml) and total spermatozoa per ejaculate (× 109) for the two frequencies were 157, 37·4; and 131·9, 19·7, respectively. Spermatozoa and seminal plasma phospholipids were determined by thin-layer chromatography and phosphorus analysis. The phospholipid components of spermatozoa, in order of decreasing concentration, were: choline phosphatides, ethanolamine phosphatides, sphingomyelin, serine phosphatides, phosphatidic acid and/or polyglycerol phosphatides. Differences between collection frequencies for the phospholipid components were not significant. The seminal plasma phospholipid contained the same component phospholipids as the spermatozoa in addition to trace quantities of lysolecithin. Sphingomyelin was the major phospholipid present in the seminal plasma.
BRUERE, A. N.; MARSHALL, R. B.; WARD, D. P. J.
doi: 10.1530/jrf.0.0190103pmid: 5815811
Summary.Two sheep of different breed displayed gross testicular hypoplasia, azoospermia, and apparent aspermatogenesis. The modal chromosome number was 55 in all tissues studied, the extra chromosome being identified as an X from sex chromatin studies on one animal. The abnormalities resemble those of chromatin-positive Klinefelter's syndrome in man, with a comparable incidence and a possibly identical cause in the two species.
FAWCETT, DON W.; HEIDGER, PAUL M.; LEAK, LEE VIRN
doi: 10.1530/jrf.0.0190109pmid: 4893612
Summary.Testes from guinea-pig and chinchilla were studied with the electron microscope after vascular perfusion of glutaraldehyde or acrolein. The improved preservation achieved by this method of fixation permitted the demonstration of an extensive system of very thin-walled lymphatic sinusoids in the interstitial tissue. The lymphatic endothelium is closely applied to the lamina propria of the seminiferous tubules on the one side and to the clusters of interstitial cells on the other. It is suggested that these lymphatics may have an important function in the distribution of androgens within the testis, in addition to their role in returning to the general circulation the large amount of serum protein that escapes from the highly permeable blood capillaries of the interstitium.
ALLANSON, M.; FOSTER, C. L.; CAMERON, E.
doi: 10.1530/jrf.0.0190121pmid: 5793904
Summary.The rate of mitosis in the adenohypophysis of colchicinetreated female rabbits has been studied in five unmated, non-parous does (controls), nineteen pregnant primiparae, seventeen suckling and five non-suckling post partum primiparae. Data are presented showing that, although the average mitotic rate was higher in Week 4 of pregnancy (4·1 mitoses/mm2) than in the unmated animals ( 1 ·7 mitoses/mm2), only in Weeks 1 and 2 of lactation (8·5 mitoses/mm2 and 12·0 mitoses/ mm2, respectively) was the increase in mitotic rate statistically significant.Five per cent of all the mitotic figures examined occurred in mucoid cells, 23% in non-granular cells, and 72% in acidophil cells (prolactin cells and somatotrophs). The majority of mitoses was found in prolactin cells (74%) during pregnancy and in somatotrophs (64%) in late lactation; in Weeks 1 and 2 of lactation, when cell proliferation was most rapid, most of the dividing cells were unidentifiable owing to lack of granules, so that at this period the mitotic rate of these two acidophil cell types could not be determined.Fluctuations in the mitotic rate in the epithelial cells of the duodenum of the animals did not appear to be correlated with the stages of pregnancy or of lactation.
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