Ergebnisse von in vitro-Befruchtungsversuchen mit Kanincheneizellen.

Abstract

Inhalt: 1. Zur Prüfung der Rückgewinnungsrate von kapazitierten Samenzellen aus dem Uterus and der Vagina wurden Kapazitatorweibchen mit 1 ml unverdünntem Sperma von 2 Böcken künstlich hesamt. Dabei belrug die Dichte 83–408 × 106 Samenzellen pro ml. Der Anteil wiedergewonnener Samzellen nach 13–17 stündiger Kapazitation lag im Durchschnitt bei 0,4–0,5%. Mit steigender Kapazitationsdauer verringerte sich die Zahl der wiedergewonnenen Samenzellen aus der Vagina, während im Uterus zwischen 9 und 17 Stunden Kapazitation die meisten Samenzellen anzutreffen waren. 2. Die optimale Kapazitationsdauer der Samenzellen betrug 13 Stunden. Dann lagen die in vitro‐Befruchtungsraten bei Verwendung von Samenzellen aus elm Uterus and der Vagina bei 69 bzw. 44%. 3. Für die Erzielung optimaler in vitro‐Befruchtungsergebnisse ist eine Samenzellkonzentration im Befruchtungsmedium von mehr als 100000/ml erforderlich. Voraussetzung für die Wiedergewinnung einer ausreichenden Zahl kapazitierter Samenzellen ist ein gut entwickelter Uterus. 4. Bei der Verwendung von Samenzellen, die im Uterus bzw. in der Vagina kapazitiert waren, entwickelten rich nach Transplantation von in vitro‐hefruchteten Eizellen 44% bzw. 21% zu Implantaten. Diese unterschiedliche Eientwicklung spricht dafür, daβ der Uterus als Kapazitationsort günstiger ist als die Vagina. Contents: (Results of in vitro‐fertilization experiments with rabbit ova A. Effect of sperm concentration and capacitation time) 1. For studying the recovery rate of capacitated sperms from the uterus and vagina, capacitator females were artifically inseminated with 1 ml of undiluted semen from 2 bucks. The density was in the range 83–408 × 106 sperms per ml. The proportion of sperms recovered after 13–17 hours capacitation was on average 0.4–0.5%. With increase in capacitation time the number of sperms recovered from the vagina fell, and most were recovered from the uterus between 9–17 hours of capacitation time. 2. The optimum capacitation time for sperms was 13 hours. The fertilization rate in vitro was then 69% for sperms from the uterus and 44% for sperms from the vagina. 3. A sperms concentration of at least 105/ml in the fertilization medium was found necessary for optimum fertilization results. 4. Using sperms capacitated in the uterus and vagina, the percentage of in vitro fertilised ova which implanted after transplantation was 44% and 21% respectively. This difference in development demonstrates that capacitation is more efficient in the uterus than in the vagina.

INVESTlGATlONS ON IN VlTRO FERTlLlZATlON OF RABBIT OVA

“…-24 hours after natural mating and the best in vitro fertilization rates were achieved when spermatozoa had resided in the uterus for 18 1 /2 hours. These results are similar to those reported by Seitz et al (15) and are different from those reported by others (8).…”

“…According to Seitz et al (15), the best in vitro fertilization rates were achieved when spermatozoa had resided in the uterus for 16-18 hours. Hahn (8), reported that optimum capacitation time for sperms was i3 hours.…”

“…Hahn et al (8), claimed that at 1east 10 5 spermatozoa must be found in the fertilization medium for in vitro .fertilization. In these experiments, the best results were obtained in experiment 7, reported here in (Table 3).…”

“…The history of attempted in vitro fertilization in mamma]s is a lengthy one, dating back at ]east to the work of Shenk (1878) with rabbit and guinea-pig eggs (12,]9). it has been shown in several mammals that some physiological changes (Capacitation) occur in sperm of the female reproductive tract that enables the sperm to fertilize the egg (1,8,9,10,14,16,17,18). it is generally believed, however, that before the requirement for capacitation of spermatozoa was appreciated, the supposed fertilization of eggs in vitro with samples of ejaculated spermatozoa or those prepared from the male tract was either a chance occurence or, more probably, an incorrect diagnosis (10).…”

“…In the context of a technology that might one day be applied to the field of animal breeding, in vitro fertilization has a]so been suggested as a possible seque] to in vitro maturation of large number of oocytes and as a means of fertilizing eggs obtained from immature animals or after excessive responses to superovu]atory treatments. In the case of human medicine a technique of in vitro fertilization has aıready been use d to overcome problems of infertility due to blocked fal10pian tubes (2,7,8,10,12,] 9). The history of attempted in vitro fertilization in mamma]s is a lengthy one, dating back at ]east to the work of Shenk (1878) with rabbit and guinea-pig eggs (12,]9).…”