Studies on the Melanocyte Stimulating Hormone-like Substance from Urine

Urine of Retinitis Pigmentosa Patient

抄録

As a part of studies on intermedia pituitary hormone (MSH), the isolation of MSH-like substance from human urine was performed to prove that MSH occurred in urine. And the physical and chemical properties of this MSH-like substance were characterized. Furthermore. their physico-chemical properties were investigated. On the other hand, it has been known that the regeneration of visual purple in the isolated retina was augmented by MSH which had relations to Retinitis Pigmentosa.
In this paper the physico-chemical difference between the MSH-like substance from normal adult urine and Retinitis Pigmentosa patient's urine is made clear and Retinitis Pigmentosa is suggested as endocrinological metabolic disease.
(I) Isolation of MSH-like Substance from Human Urine and its Properties.
The active material is extracted with warm acetic acid from urine, precipitated with acetone-ether mixture and purified by the charcoal adsorption procedure. Further purification is carried out by ion exchange chromatography. This MSH-like substance is a slightly basic polypeptide which migrates as a single band when it is submitted to ionophoresis on paper in pyridine-acetic acid buffer at pH 6.5. It seems that their physical properties are very similar to the MSH from human pituitary gland.
(II) Physico-chemical Properties of Urinary MSH-like Substance
(1) This substance possesses a melanocyte expanding activity and inhibits the influence of large doses of Vitamin C which suppress a melanocyte expanding action, in the same way as that of MSH from pituitary gland.
(2) This substance auguments the activity of tyrosinase by Kobowitz's method at 10 min. after initiation. This effect is the same as that of MSH from pituitary gland.
(3) This substance decreases the level of Vitamin A in rat liver, and increases the urinary excretion of estrogen in rabbit.
(4) This substance expands slightly the amplitude of heart palpitation on Bufo, but does not affect to the blood pressure in rabbit.
(III) Difference between the Urinary MSH-like Substance of Normal Adult and that of Patient
(1) The urinary MSH-like substance from patients does not posses the activity of melanocyte expanding.
(2) This substance from diseased urine does not show the effect of decreasing Vitamin A level in rat liver and of increasing urinary estrogen excretion in rabbit.
(3) This substance from diseased urine has no absorption at 1100cm^-1 of ultra-red absorption spectrum.