|Budget Amount *help
¥1,800,000 (Direct Cost : ¥1,800,000)
Fiscal Year 1996 : ¥400,000 (Direct Cost : ¥400,000)
Fiscal Year 1995 : ¥1,400,000 (Direct Cost : ¥1,400,000)
Phosphodiesterase (PDE), an enzyme hydrolyzing 2 cyclic nucleotide monophosphates, plays a pivotal role in the action of antidiuretic hormone (ADH) or atrial natriuretic hormone (ANP) in kidney. Although less concentarted urine in neonatal period has been known, an involvement of PDE has not been elucidated yet. Thus we investigated PDE activity in developmental maturation in "Developmental Change of Phosphodiesterase Activity in Rat Kidney, Heart and Liver : An Involvement of Increased Phosphodiesterase Activity in Limited Urinary Concentration Ability in Neonatal Period", which will be pressed in the "Jichi medical School Kiyou, vol.20,1997". In this report, we found that PDE activity alters through maturation, and its alteration pattern differs from organ to organ. In the next study, we invesigated an involvement of mechanical stress, such as changes of osmolality, in the activity of PDE.We will send the study "Alteration of the Phosphodiesterase Activity by Osmolality in Rat Inner Medullary Collecting Ducts Cell" to the "Nephrology" in the first half of this spring. In that report, we examined whether PDE activity is altered by osmolality. We found that PDE,especially PDE type-I,chages its activity by handling osmolality. From these reports, we concluded that PDE alters through maturation, and its alteratin being involved, with ambient osmolality. Therefore, it will be of suggestive that factors participating in the osmolality around kidney cells, such as meal contents, are relted to the maturational change of PDE in kidney.