The inhibition of the ovarian response with repeated gonadotropin, obtained from pregnant mare serum and urine of pregnant women use, has been described by several authors. Among the possibilities put forward to explain this antigonadotropic mentioned action of a mechanical obstacle in the ovarian surface; the ovarian exhaustion; The inhibitory action of the presence of active exert lutea; antihormone the one according to the system proposed by Collip; and finally, the possibility of an antigen antibody reaction

The coastal and native resident of the height 4,560 meters, statistically no different in the excretion of 17 ketosteroids and neutral reducing the steroids. The coastal within the first 12 months of its adaptation to high altitude, showing changes in the urinary excretion of these steroids.

Excess progesterone and luteinizing ovarian hyper apparently produce embryonic death, not only in pregnancies that are concomitantly begin to endogenous or exogenous excess progesterone, but also in pregnancies that existed before hormone produced surcharge.

The results point out some effects of the ovaric hormones like substance over the early embryological development. Estrogens show a tendency to decrease the egg segmentation rate and to decrease the mucin coat around the egg. In the other hand, progesterone produces only increase of the mucin coat.

The results show that it is necessary a balance between the PMSG and the CG to obtain ovulation of the induced mature follicles. The hemorragie follicles without ovulation could he produced by insufficient amounts of CG in relation to the PMSG used to induce the follicular maturation.

The results point out some effects of the ovaric hormones like substance over the early embryological development. Estrogens show a tendency to decrease the egg segmentation rate and to decrease the mucin coat around the egg. In the other hand, progesterone produces only increase of the mucin coat.

The results show that it is necessary a balance between the PMSG and the CG to obtain ovulation of the induced mature follicles. The hemorragie follicles without ovulation could he produced by insufficient amounts of CG in relation to the PMSG used to induce the follicular maturation.

Anoxia crónica, en dos carneros Corriedale, importados desde el nivel del mar (Chile), y traídos a Huancayo (3200 mts. de altitud), ha producido azzospermia. Ambos sufrían de mal de montaña. Uno de ellos, desarrolló un proceso reversible de azoospermia. Después de unas semanas, los espermatozoides aparecieron de nuevo y el animal mostró el deseo sexual. El carnero se está recuperando: pH y la movilidad de su líquido seminal, puede considerarse normal. El número de células se incrementa mucho. El otro carnero no obstante lo hecho de haber marcado el deseo sexual, después de cinco meses, está todavía en la azoospermia.