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SUDHANSU K. DEY, JAYASREE SEN GUPTA and C. DEB

Summary.

The activity pattern and functional significance of leucine aminopeptidase (LAP) have been studied in the testes of oestrogen-treated, cryptorchid and HCG-treated guinea-pigs. The enzyme was present only in the Leydig cells and showed marked fluctuations in its activity pattern, which correlated closely with alterations in the functional activities of the Leydig cells. Hyperfunctioning Leydig cells exhibited enhanced LAP activity, whereas hypofunctioning of these intertubular cells resulted in a diminution in the enzyme activity. The LAP activity in the intertubular Leydig cells may be regarded as a cytochemical marker enzyme in the assessment of Leydig cell function in the guinea-pig testes under varying experimental conditions.

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B. D. Schanbacher

Summary. Surgically induced cryptorchidism in rams resulted in elevated serum concentrations of LH but near-normal concentrations of androgen (testosterone and 5α-DHT). Injections of ovine LH (2 × 50 μg; 2 × 500 μg) resulted in maximal androgen secretion in the intact rams and similar but lower concentrations in cryptorchid rams. Peak concentrations were 14·9 and 8·5 ng/ml in the intact and cryptorchid rams respectively (P < 0·05).

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R. JONES

As yet, there is little knowledge as to the possible side effects of vasectomy on the function of the epididymis. In rats and bulls, it has been reported that vasectomy causes a spermatocoele to develop at the site of ligation on the vas deferens or in the epididymis (Amann & Almquist, 1962; Igboeli & Rakha, 1970; Hooker & Gilmore, 1972); in other species, notably the rabbit, this does not occur (Macmillan, Desjardins, Kirton & Hafs, 1968; Paufler & Foote, 1969). Some reports have claimed that vasectomy causes atrophy of the testis and disruption of spermatogenesis (Laumas & Uniyal, 1967; Sacher & Schilling, 1973) but most workers agree that, at least in the early stages, vasectomy only affects the terminal parts of the epididymis. It is not known what influence this might have

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JAMES T. DAVIS and JOHN G. CONIGLIO

Summary.

Lipid and fatty acid composition of testes were determined in normal rats and in rats treated with various factors affecting spermatogenesis. Cryptorchidism and cadmium chloride treatment resulted in about 30% loss of weight of testes. In the former group there was a decrease in phospholipid and an increase in concentration of cholesterol and of triglycerides. In both groups there was a decrease in concentration of palmitate and docosapentaenoate compared to normal testes. Histological examination revealed atrophy of the germinal epithelium with disappearance of spermatids and spermatozoa and of most of the spermatocytes. Treatment of rats with two anti-spermatogenic drugs resulted in no change in the concentration of docosapentaenoic acid and a reduction in the number of spermatogonia and spermatocytes. The chemical and histological changes observed are consistent with the hypothesis that the docosapentaenoate of rat testicular tissue is associated with the spermatids and spermatozoa.

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Kusum Vermat, M. M. Misro, H. Singh, Sudha Mahajan, A. R. Ray and S. K. Guha

Summary. An alternate co-polymer of styrene and maleic anhydride was dissolved in dimethylsulphoxide and injected into the vas deferens of rats. The polymer was retained in the vas deferens and the morphological changes detected were confined to the mucosa. When the polymer was removed by flushing dimethylsulphoxide, the mucosal structure became normal within 2 weeks.

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T. B. Haugen, V. Hansson and P. Fritzson

Summary. High specific activity of uridine kinase was found in cultured peritubular cells (3·0 nmol/min per mg protein) which was more than 3-fold higher than that found in cultured Sertoli cells (0·79 nmol/min per mg protein). In the various classes of germ cells a decrease in specific uridine kinase activity was associated with increased maturity of the cells, primary spermatocytes, round spermatids and spermatozoa showing 1·3, 0·65 and 0·16 nmol/min per mg protein, respectively. A relationship between uridine kinase activity and the rate of RNA synthesis in these cells is suggested. A decrease in specific uridine kinase activity in testis with increasing age supports the finding of lower uridine kinase in mature germ cells than in earlier germ cells and somatic cells. This finding is further supported by the observation that cryptorchidism, which is associated with a time-dependent depletion of germ cells, resulted in an increase in specific uridine kinase activity. The results indicate that pyrimidine salvage is important in earlier germ cells, as well as in somatic cells in the testis, to produce substrates for nucleic acid synthesis.

Keywords: Sertoli cells; peritubular cells; germ cells; cryptorchidism; uridine kinase; pyrimidine salvage

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H Krzanowska and B Bilinska

Nuclei of mouse Sertoli cells were examined on air-dried toluidine blue-stained preparations to analyse factors influencing the aggregation of heterochromatin into chromocentres. For the CBA strain males tested at 1.3, 2, 3, 6, 9 and 12 months of age, mean numbers of heterochromatin bodies were 4.8, 2.4, 2.1, 1.8, 1.6 and 1. 4, respectively; two chromocentres predominated from 2 to 9 months of age. In the KE strain, heterochromatin aggregation was significantly accelerated; nuclei containing only one chromocentre were predominant from 6 months. The number of chromocentres did not change with the stages of the seminiferous cycle, and after 1 month of cryptorchid condition. Cryptorchidism resulted in disruption of spermatogenesis and Sertoli cell dysfunction, as demonstrated by the lack of immunohistochemically detectable androgen receptors. The difference in the number of chromocentres between KE and CBA Sertoli cells persisted after 3 days of in vitro culture, but unidentified cells with numerous chromatin bodies were also observed. Testing recombinant inbred strains indicates that at least two genes are involved in the difference in the number of chromocentres between progenitor KE and CBA strains; however, no correlations were found with 15 marker loci or with parameters linked to reproduction. Of the eight strains tested, AKR and C3H showed a 'CBA-like' chromocentre pattern; C57BL, B10.BR, B10.BR-Y(del) and KP were 'KE-like'; and BALB/c and DBA/2 were intermediate. The results showed that centromere aggregation in the Sertoli cell progresses throughout the life of a male in a strain specific manner; however, its functional significance remains unknown.

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M. H. JOHNSON

Summary.

Immunological damage induced by iso-immunization of guinea-pigs with testis in adjuvant is most readily observed in the rete testis and vasa efferentia and is less frequently present in the testis and epididymis. Possible reasons for the greater vulnerability of the rete testis and vasa efferentia are discussed. The testis shows interstitial inflammation and an invasion of tubules by eosinophils and mononuclear cells. The tubular barrier to acriflavine, and possibly also to γ-globulin, partially breaks down during the invasive phase of initial damage but is restored before normal spermatogenesis is re-established. It is suggested that the occurrence of testicular damage is dependent upon the immune response, of whatever type(s), overcoming the protective effect of the blood-testis barrier.

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W. R. GOMES

In his recent review of carbohydrate metabolism in the testis, Free (1970) summarized evidence that glucose stimulates respiration of testis tissue in vitro from adult rats, mice, rabbits, rams and chickens. However, when most germinal elements are absent from the testis (e.g. following cryptorchidism, hypophysectomy, irradiation or treatment with antispermatogenic chemicals), the stimulation of oxygen consumption by exogenous glucose is lost (Free, 1970). These results suggest that glucose is oxidized primarily in the more mature germinal elements rather than in Sertoli cells or interstitial tissues (Tepperman, Tepperman & Dick, 1949; Free, Massie & VanDemark, 1969; Free, 1970), but one cannot overlook the possibility that biochemical alterations may result from changes in the endocrine (Johnsen, 1970) or nutrient (Massie, Gomes & VanDemark, 1969) environment during such treatments, or that enzymatic capabilities

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U. A. SOD-MORIAH, G. M. GOLDBERG and E. BEDRAK

Summary.

Heat-acclimatized rats were exposed to an ambient temperature of 35°C, and the effect on testicular histology, reproductive capacity and body and scrotal temperature was evaluated. Both deep body and intrascrotal temperatures of these animals were found to be higher than those of control rats maintained at 22°C. The intrascrotal temperature in the heat-acclimatized animals and the deep body temperature in the controls were similar. Breeding experiments proved the heat-acclimatized animals to be capable of mating and reproducing, although at a lower rate than the controls. The heat reduced only the mating rate and fertilization. After conception, the groups showed no difference. Histological screening revealed degenerated seminiferous tubules randomly scattered in the testes of the heat-acclimatized rats although most of the tubules showed normal spermatogenesis. These localized necrotic foci resemble the overall appearance of a cross-section of a cryptorchid testis. The heat-acclimatized animals, however, maintain a body to scrotum temperature gradient which enables spermatogenesis to proceed despite the elevated temperatures.