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To determine whether anti-Müllerian hormone (AMH) is responsible for the gonadal anomalies observed in bovine female "freemartins" united by placental anastomosis to a male twin, fetal rat and ovine prospective ovaries were exposed to purified bovine AMH in organ culture. We show that AMH reproduces the caracteristical "freemartin effect"; namely the initial inhibition of gonadal and germ cell development, and the differentiation of fetal Sertoli cells forming seminiferous cord-like structures and producing immuno and bioactive AMH. In addition, fetal ovine ovaries submitted to AMH release testosterone instead of estradiol due to an inhibiting effect upon the biosynthesis of their aromatase enzyme. Taken together, these results indicate that AMH is probably the testicular factor responsible for the abnormalities of freemartin gonads and suggest that this hormone could play a pivotal role in normal testis differentiation.

Mitochondria from heart of rats fed a diet rich in rapeseed oil for two months from weaning, oxidized oleic acid a little better than those from animals fed a control diet containing peanut oil; but their activity decreased much more in presence of potassium cyanide which is an oxidation inhibitor. When observed by electronic microscopy, mitochondria from heart of rats fed rapeseed oil were more mumerous and more mitochondria of great size were encountered as compared with control rats. Biochemical data seemed to show a decrease of activity or quantity of certain enzymatic systems in mitochondria from heart of animals fed rapseed oil. Cyanide could more easily inhibit these enzymatic systems because of their deficiency. It can be thought that it is the mitochondria of great size which are implicated in this phenomenon since their growth is not accompanied by an increase of their content in certain enzymes which are just sensitive to cyanide. A mixture richer in mitochondria of big size, thus poorer in certain enzymes for an equal protein content in drastic conditions, such as partial anoxia since cyanide blocks the respiratory chain.

In this work, were studied the conditions of erucic acid (cis-docosenoic, n-9) shortening by using Rat liver mitochondrial preparations which were incubated in vitro with [14-14C] erucic acid (22:1), with inhibitors of the respiratory chain (rotenone, cyanide) or not, with activators of either the shortening reaction (NAD+, NADP+), or beta-oxidation (malate, carnitine, cytochrome c) or not. The shortening activity was measured by the amount of 14C radioactivity recovered in the shorter fatty acids formed (20:1, 18:1, 16:1) when beta-oxidation was inhibited. The beta-oxidation activity was measured by the amount of 14C recovered in the acid-soluble products (P A S). The incubations were performed under conditions which were the least favourable to peroxysomal activity. Data showed that, with increasing amounts of albumin, which inhibits peroxysomal activity, increasing amounts of shorter fatty acids (20:1, 18:1, 16:1) were formed from erucic acid. This shortening reaction was strongly stimulated by NAD+, more than by NADP+; it was also stimulated by cytochrome c and much more when both NAD+ and cytochrome c were added. Similar data were observed in beta-oxidation, except that practically NADP+ did not exhibit any stimulating effect. Oxidation of NADH by mitochondria only occurred when cytochrome c was added to the medium and was not modified by the addition of ADP or rotenone. These data show that liver mitochondria are capable of shortening erucic acid, as are peroxysomes. This shortening reaction is highly NAD+-dependent and seems to be localized outside the matrix. This system could constitute a second route for utilization of fatty acids in mitochondria, besides the well-known path of beta-oxidation.

Presentation of a simple method for reinforcement of the closure of laparotomies by so-called "brandebourg" full thickness sutures. In our experience, this technique is not ischaemic, ensures axial compression, and renders wound care easy, being simple, effective and cheap.