PITUICYTES AND THE ORIGIN OF THE ANTIDIURETIC HORMONE 1

Dogs were kept in a state of excessive hydration by the oral administration of water, or its infusion into the stomach, for periods varying from 3 hr to 10 days. The effect of this procedure on the stainable neurosecretory material (NSM) in the hypothalamus was determined by histological examination.At the end of the longer periods of hydration there was seen an accumulation of NSM in the descending tracts from the paraventricular and supraoptic nuclei. In the 10-day hydrated animal a high proportion of the cell-bodies in these nuclei were depleted of NSM. The staining properties of the pars nervosa did not differ from normal.The hydrated animals exhibited large numbers of vesiculated neurones in the hypothalamic neurohypophysial nuclei.

Section: Water Deprivationmentioning

confidence: 99%

mentioning

confidence: 99%

The Effect of Long Periods of Continuous Hydration on the Neurosecretory Material in the Hypothalmus of the Dog

Andersson¹,

Jewell²

1957

“…If he was bold in this, he was more conservative when it came to the theories of others: in his 1955 monograph, he still inclined to the view that the posterior pituitary contained endocrine cells that were innervated by hypothalamic neurons (Harris 1955). Although he conceded that the neurosecretory origin of the posterior pituitary hormones (Leveque & Scharrer 1953) was an 'attractive hypothesis', he declared that 'sweeping statements have been made at various times by the protagonists of the neurosecretory hypothesis' and warned that 'such claims as these, which run contrary to a great deal of established data should be taken with reserve' (Harris 1955: 264). In particular, Harris rejected the notion that the Gomorri-stainable material present in the hypothalamo-hypophysial tract was the histological representation of antidiuretic hormone, as had been argued by the Scharrers.…”

Section: Introductionmentioning

confidence: 99%

60 YEARS OF NEUROENDOCRINOLOGY: The posterior pituitary, from Geoffrey Harris to our present understanding

Leng¹,

Pineda²,

Sabatier³

et al. 2015

Geoffrey Harris pioneered our understanding of the posterior pituitary, mainly with experiments that involved the electrical stimulation of the supraoptico-hypophysial tract. In the present essay, we explain how his observations included clues to the pulsatile nature of the oxytocin signal -clues that were followed up by subsequent workers, including his students and their students. These studies ultimately led to our present understanding of the milk-ejection reflex and of the role of oxytocin in parturition. Discoveries of wide significance followed, including: the recognition of the importance of pulsatile hormone secretion; the recognition of the importance of stimulus-secretion coupling mechanisms in interpreting the patterned electrical activity of neurons; the physiological importance of peptide release in the brain; the recognition that peptide release comes substantially from dendrites and can be regulated independently of nerve terminal secretion; and the importance of dynamic morphological changes to neuronal function in the hypothalamus. All of these discoveries followed from the drive to understand the milk-ejection reflex. We also reflect on Harris's observations on vasopressin secretion, on the effects of stress, and on oxytocin secretion during sexual activity.

“…This neurosecretory material migrates along the axons of the infundibular stalk to the posterior pituitary where it is deposited and stored (Leveque & Scharrer, 1953). Under unstimulated conditions a parallel relationship exists between the amount of neurosecretory material and neurohypophysial hormones in different parts of the hypothalamo-hypophysial system (Scharrer & Scharrer, 1954;Hild & Zetler, 1951, and under conditions of chronic stimulation, e.g.…”

Section: Introductionmentioning

confidence: 99%

“…Under unstimulated conditions a parallel relationship exists between the amount of neurosecretory material and neurohypophysial hormones in different parts of the hypothalamo-hypophysial system (Scharrer & Scharrer, 1954;Hild & Zetler, 1951, and under conditions of chronic stimulation, e.g. water deprivation, the administration of hypertonic saline, or the polyuria of alloxan diabetes, there is a decreased amount of neurohypophysial neurosecretory material (Leveque & Scharrer, 1953;Gaunt, Lloyd & Chart, 1957), which is proportional to the decrease in vasopressin (Ortmann, 1950(Ortmann, , 1951 and oxytocin (Sawyer & Roth, 1953). Similarly, lactation decreases both the content of neurosecretory material in the neurohypophysis (Racadot, 1957;Rennels, 1958;Rinne, 1960), and that of vaso¬ pressin and oxytocin (Rennels, 1958;Heller, 1959).…”

Section: Introductionmentioning

confidence: 99%

Dissociation Between the Content of Vasopressin and Neurosecretory Material in the Rat Neurohypophysis

Moses¹,

Leveque²,

Giambattista³

et al. 1963

Vasopressin content and the staining of neurosecretory material with chrome-alum-haematoxylin-phloxin were observed in the neurohypophysis of rats following injection of formalin. The amount of neurosecretory material was reduced during the period up to 90 min. after formalin injection while no change in the vasopressin content was observed. These observations support the concept that the neurosecretory material is distinct from vasopressin and may be acting as a carrier or precursor for the hormones of the neurohypophysis.