The vasa vasorum patterns in the fetal aorta of sheep

In 37 aortae of sheep fetuses of various ages, the medial vasa vasorum were investigated. The aortic segments which had more than 29 medial lamellar units displayed medial vasa vasorum. This occurred in the second month of gestation for the ascending and descending segments, and in the fifth month for abdominal aorta.

Patterns of the vasa vasorum network in the uterine arteries of domestic and wild mammals

The vasa vasorum patterns in the uterine arteries of virgin and multiparous domestic and wild mammals were investigated. In young virgin females the vasa vasorum network was present in the adventitia. The uterine arteries of adult multiparous females showed various degrees of intimal hyperplasia and the adventitial vasa vasorum were piercing the arterial wall. The depth of penetration was related to the degree of intimal hyperplasia, namely, to the thickness ratio between the intima and media. Intimal vascularisation occurred in those arteries in which the hyperplastic intima overpassed the thickness of the media. These capillaries originated from the adventitial vasa vasorum network and were penetrating transmedially.

Influence of neonatal gestagen injection on the differentiation of psychosexuality in female rats

The influence of neonatal injection of gestagens with androgenic, oestrogenic, or no side activities on sexual behaviour differentiation was studied in female rats. Single injections of norethindrone acetate, ethinodiol diacetate and norethindrone oenanthate, which are steroids with inherent oestrogenic activities, suppressed the capacity to display lordosis responses in adult life after hormonal stimulation. Both norethindrone esters also caused a certain shift of psychosexuality towards masculinity. The incidence of bisexuality was, however, extremely low in all the rats.

Androgenic gestagens, i. e. d.l-norgestrel and norethandrolone, did not suppress female differentiation of sexuality; there was moreover no increase in male behavioural patterns. Norhydroxyprogesterone caproate, megestrol acetate and a new synthetic progesterone derivative (clomegestone acetate), all steroids with no side activities, were without any effect on mating behaviour differentiation. Allylestrenol and medroxyprogesterone acetate suppressed the capacity to display feminine mating patterns but did not induce male behaviour. It is most likely, however, that this result is due to the administration of higher gestagen doses rather than to any side effects of either steroid.