title: Levels of neurohypophyseal peptides in the rat during the first month of life. II. Response to physiological stimuli.
abstract: Levels of vasopressin, oxytocin, and neurophysin were measured by RIA in the hypothalamus, pituitary, and plasma of infant rats (2-30 days old). At all ages, ip injection of a hypertonic solution of 5 g/100 ml NaCl produced a marked increase in levels of vasopressin and neurophpysin in plasma, up to 21 microU/ml and 51 ng/ml, respectively. After dehydration, there was a decrease of 26-38% in the levels of neurohypophyseal peptides in the pituitary. Depletion of neurohypophyseal peptides from the pituitary was greater after 24 h of dehydration in younger rats (26%) than in older rats (7%). Levels of vasopressin in plasma were less than 1.7 microU/ml after dehydration in younger rats but were greater in older rats. Immaturity of the neurohypophysis may contribute to the inability of newborn rats to withstand prolonged dehydration.
mesh_terms: D000818:Animals; D007031:Hypothalamus / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D009481:Neurophysins / Q000378:metabolism*; D010121:Oxytocin / Q000378:metabolism*; D010904:Pituitary Gland, Posterior / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D051381:Rats; D012965:Sodium Chloride / Q000494:pharmacology*; D014667:Vasopressins / Q000378:metabolism*
chemical_list: D009481:Neurophysins; D014667:Vasopressins; D012965:Sodium Chloride; D010121:Oxytocin