Changes in the Amount of Adrenergic Transmitter in the Female Genital Tract‐of Rabbit During Pregnancy

The noradrenaline present in the female reproductive organs – ovary, oviduct, uterus, and vagina – of the rabbit is stored in adrenergic nerves. Fluorescence microscopy revealed that these nerves are related to the vascular bed and the smooth muscle walls; besides the vascular nerves the ovary also contains adrenergic nerves unrelated to the vessels. The adrenergic innervation of the genital organs originates from sympathetic ganglia located near the effector organs, as well as from pre‐ and paravertebral ganglia. During the former half of pregnancy a marked increase in neuronal noradrenaline occurs in the reproductive organs, except in the ovary. In the uterus and the vagina this increase is followed by a dramatic decrease in total noradrenaline during the latter half of pregnancy; by the end of pregnancy the uterus is almost completely devoid of noradrenaline‐containing sympathetic nerves. The findings are discussed in terms of an humoral influence on the adrenergic neurons supplying the female reprocluctive tract.