Gamma-glutamyl transpeptidase activity in the epididymis during fetal and postnatal development in rats.

The histochemical and biochemical distributions of gamma-glutamyl transpeptidase (gamma-GT) were investigated in the epididymis of rats during fetal and postnatal development. In the epididymal homogenates, gamma-GT activity was detected on the fifth day after birth. A sharp increase was observed after 30 days of life in the caput homogenates. Moderate levels of the enzyme were found in the cauda epididymis. Gamma-GT is histochemically detected from the 15th day of gestation in Wolffian ducts and in 17- to 18-day-old fetuses in newly differentiated epididymal tubules. Enzyme activity, was associated with the plasma membranes (apical, lateral, and basal), was preponderant on the apical part of the epithelial cells. During the first 15 days of the postnatal life, the histochemical reaction intensities were identical from the caput to the cauda epididymidis. From the 18th day onwards, enzyme activity decreased in the corpus and in the cauda, while gamma-GT increased in the caput epididymidis, and a strong activity was found on the apical surface of epithelial cells. Weak or moderate gamma-GT activity of spermatozoa in the caput tubules, increasing steadily from caput to cauda epididymidis, suggests that gamma-GT may be related to the functional maturation of spermatozoa.

Autoradiographic localization of [3H]oestradiol in epididymis, seminal vesicles and prostate of the fetal guinea-pig.

The selective uptake and localization of radioactivity in the fetal male reproductive organs (epididymis, seminal vesicles and prostate) of the guinea-pig (50-60 days of gestation) after in-vivo and in-situ subcutaneous injection of [3H]oestradiol was investigated by autoradiography. In 50-day-old fetuses, the different areas of the epididymis showed selective retention of radioactivity in the nuclei of peritubular and stromal cells surrounding the epididymal duct; no retention was observed in the epididymal epithelium. A similar distribution of silver grains was observed in the 60-day-old fetus. Seminal vesicles and prostate sections from both 50- and 60-day-old fetuses showed concentration and retention of radioactivity only in stromal cells, whereas the epithelium did not exhibit silver grains. In all the tissues studied, the nuclear labelling was abolished after injection of [3H]oestradiol plus a 100-fold excess of non-labelled oestradiol. As the mesenchyme surrounding the epithelia of the epididymis, seminal vesicles and prostate were labelled selectively with [3H]oestradiol, it is suggested that during fetal life of the guinea-pig the mesenchymal stroma of these fetal male reproductive organs may be considered as a target tissue for oestrogen.

[Demonstration of the presence of an ultrafiltrable substance in human serum activating somatomedin A]. / Mise en évidence d'une substance ultrafiltrable dans le sérum humain activant la somatomédine A.

Human serum contains an ultrafiltrable factor which stimulates the somatomedin activity measured by 35SO4 incorporation into pelvic cartilage of chick embryo, this ultrafiltrable factor activates native serum somatomedin or partially purified somatomedin. The molecular weight determined by fractionated ultrafiltration or chromatography on Biogel P2 is about 350-500 daltons.

[Laron type familial dwarfism; genetic primary somatomedin deficiency]. / Le nanisme familial de type Laron, deficit gnetique primaire en somatomedine.

Five children from 3 different families presented with severe dwarfism and the morphological and biological features described by Laron: familial occurrence, small stature, peculiar facies, high levels of plasma HGH and resistance to treatment by GH. This therapeutic inefficiency is expressed by an absence of physical growth and unchanged nitrogen balance, during a prolonged treatment. The plasma levels of somatomedine were very low (K. Hall's biological method) and not influenced by administration of exogenous HGH. These findings suggest that the fundamental disorder is not an abnormal structure of the molecules of GH. This hypothesis seems further confirmed by the structural analysis of plasma HGH, which gave the same results as those of the reference GH.

[Activity of blood somatomedin during childhood in normal subjects and in delayed growth]. / L'activité somatomédine du sérum au cours de l'enfance chez le sujet normal et dans les retards de croissance

A hundred sera from children, were used to evaluate normal levels of somatomedin activity and pathological levels. The results showed that the level of this activity in the blood, rises gradually during infancy, to reach normal adult reference level by postulate, equal to 1. Although the values are widely dispersed in each sample, the general phenomenon of their increase in infancy remains significant. The patients with somatotropin deficiency, have very low somatomedin values which become normal under the influence of injection of human growth hormone. A very unusual case is that of Laron's dwarfism with very high values of HGH in the plasma, and very low levels of somatomedin and, clinical and laboratory indifference to injections of exogenous HGH. The prospects of progress in the techniques of study of somatomedin will be of great service in the near future.

[Sleen enhancement reactions in chick embryo after spleen homografting: autohistoradiography after labeling of graft with tritiated thymidine]. / Contribution à l'études des réactions splénomégaliques de l'embryon de poulet consécutives à l'homogreffe de fragments de rate : analyse par autohistoradiographie après marquage du greffon à la thymidine tritiée

The use as a graft involving an embryonic spleen enhancement of the spleen of an embryo previously grafted (with adult spleen) allowed a very high labelling (3H-thymidine) of the graft and therefore the study of ingrafted cells behaviour: a) on the chorioallantois membrane, b) on the host spleen. In the last case, only a very little number of labelled cells was observed and the whole results confirm the hypothesis of an active participation of the embryo in the case of such an haemopoietic spleen reaction.