pituitrin and sapropterin

Topics: Animals; Biopterins; Body Water; Dehydration; Hypothalamus; Male; Oxytocin; Pituitary Gland, Posterior; Rats; Rats, Wistar; Reference Values; Vasopressins

Experiments were performed to test a possible role of (6R)-5,6,7,8-tetrahydro-alpha-biopterin dihydrochloride (BH4) in the neurohypophysial vasopressin and oxytocin content in euhydrated and dehydrated rats. Chronic treatment with BH4, administered to not dehydrated animals, was followed by a significant decrease of neurohypophysial vasopressin, but not of neurohypophysial oxytocin. In dehydrated animals the neurohypophysial vasopressin content decreased progressively; this process was not affected significantly by BH4. In rats dehydrated and treated simultaneously with BH4 the decrease of neurohypophysial oxytocin content was distinctly less marked.

Topics: Animals; Biopterins; Dehydration; Male; Oxytocin; Pituitary Gland, Posterior; Rats; Rats, Wistar; Vasopressins

Incubation of neurointermediate lobes in Locke's solution containing 0.13 mumol.l-1 (6R)-5,6,7,8-tetrahydro-alpha-biopterin dihydrochloride (THB4) resulted in an inhibition of bioassayed vasopressin secretion and in an increase of that of oxytocin both under resting conditions as well as during depolarization due to excess potassium. It is suggested that some events related to THB4 and localized in the neural lobe are involved in the mechanism of vasopressin and oxytocin release.

Topics: Animals; Biopterins; Male; Oxytocin; Pituitary Gland; Rats; Rats, Inbred Strains; Vasopressins