EVIDENCE FOR THE HORMONAL NATURE OF THE OXYTOCIC PRINCIPLE OF THE HYPOPHYSIS

Abstract

In 12 rabbits, 2 to 80 hrs. post partum, electrical stimulation in the region of the infundibular stalk produced a definite increase in uterine activity, characterized by increased frequency and amplitude of contractions. This response resembled closely that obtained by inj. of pitocin and differed radically from the effects of epinephrine. The response persisted after spinal transection, after section of the splanchnic nerves and after vagotomy, but was effectively blocked by electrolytic lesions placed directly in the stalk of the pituitary body. The pituitary complex apparently secreted the oxytocic principle and the latter need not be regarded as a pharmacological principle but might properly be classed as a hormone of the pituitary gland.