() ,, NaCl,,NaCl. ; ,;

() -: . , (constant fraction reabsorption) . 65-70%.: .

: . , , Na+, Na+,. .

,

() , 1., ,, . 2.,-- , NaCl. 3.NaCl. () (antidiuretic hormone, ADH) (argininc vasopressinVP) 1.: ,-

-ADH-

2.: V1 V2 NaCl

3.: (ADH)V2 cAMP AQP-2 ADH ,, .

Peter Agre Johns Hopkins University School of Medicine Baltimore, MD, USA

Peter Agre, born 1949 (54 years) in Northfield, Minnesota (US citizen). Medical Doctor 1974 at Johns Hopkins University School of Medicine, Baltimore, USA. Professor of Biological Chemistry and Professor of Medicine at Johns Hopkins University School of Medicine, Baltimore, USA. That the body's cells must contain specific channels for transporting water was suspected as early as the middle of the nineteenth century. However, it was not until 1988 that Peter Agre succeeded in isolating a membrane protein that, a year or so later, he realised must be the long-sought-after water channel.

Peter Agres experiment with cells containing or lacking aquaporin. The aquaporin is necessary for making the cell absorb water and swell.

Water permeability of aquaporin-1 (AQP1) expressed in Xenopus oocytes. When transferred to hypo-osmolar buffer for 2 min, control water-injected oocytes exhibit negligible swelling (left). Under the same conditions, oocytes previously injected with AQP1 cRNA rapidly swell and explode (right).

The physiological importance of the aquaporins is perhaps most conspicuous in the kidney, where some 150-200 liters of water need to be resorbed from the primary urine each day. This is made possible mainly by the AQP1 and AQP2 aquaporins. AQP1 is expressed in the proximal tubules and the descending vasa recta, while AQP2 is expressed in the collecting duct. The expression of AQP2 at the plasma membrane is regulated by vasopressin, and decreased or increased AQP2 levels have been associated with nephrogenic diabetes insipidus as well as with several conditions associated with fluid retention such as congestive heart failure (King and Yasui, 2002).

4.ADH1 280-290mOSM ADH275-290mOsm,ADH 0-4pg/ml; 1%ADH1pg/ml 289-307mOsmADH 5pg/ml

: 1-2% () ADH

(1000) ,, (?)

(2) : ADH ADH(3) ADH: II ADH: (4-6,7)

() -- (renin-angiotensin system)1

2. II ADH

3. (aldosterone) + - DNA mRNA Na+, Na+; ATP, Na+; Na+, Na+-K+ Cl-. 45

4. PGE2 IINO

(clearance) : () , , .

: U: V: P: UV1. .2. . (?)

. () 1. (F), (E)(R).UV () = F P () - E() + R()F=, P= REU , . (125ml/).

2. ,. , , . (L/24)=() , ,.

= , P= 1-3mg/100ml, , 0., 660ml/min. 55%, =660/55 100 = 1200ml/min() 125 ml/min, ; = (?), =70ml/min, 125 ml/min, ; 125 ml/min.

. 1. 2-4 . 2.

3

10cm H2O 700ml> 35cm H2O > 400500ml,> 10cm H2O > 70cm H2O