Renal proton magnetic resonance and bound and free water distribution in the normal, angiotensin II-and ADH-infused rats, before and after Gd DTPA paramagnetic enhancement.
Female Charles River rats, 250-300 g, were used in all experiments. The rats were divided into the following experimental groups. Group A: Normal rats were injected with 1 ml saline intravenously. Exactly after 8 min the kidneys were excised as rapidly as possible. The papilla was dissected and cortical and medullary slices were prepared. Immediately following the excision T1 and T2 were measured with a Bruker PC-20 Minispec spectrometer operating at 20 MHz at 37 + 1 degree C. Water content (PW) of the samples was calculated as a percentage tissue weight, after 24 h drying to constant weight. The fraction bound (FB = % water bound) and hydration fraction (% water bound/g solid) were computed from T1 relaxation time, and the PW, according to a fast proton diffusion model. Group B: As group A but 3 min after the saline administration bolus of 1 ml solution of Gd DTPA. 70 mumol/kg body weight, was given intravenously. Group C: As group A but instead of saline the rats were given a solution of ADH (5 mU/kg body weight i.v.). Group D: As group C plus Gd DTPA as in group B. Group E: As group A but instead of saline the rats were given a solution of angiotensin II (Ag II) (5 micrograms/kg body weight). Group F: As group E plus Gd DTPA as in group B. In groups B-F the magnetic resonance and water distribution were determined and calculated as in group A. In the normal rats there is a prolongation of T1, T2 and an increased total water content from the cortex to the papilla.(ABSTRACT TRUNCATED AT 250 WORDS)
Iaina
A
A
Department of Nephrology, Barzilai Medical Centre, Ashkelon, Israel.
Abrashkin
S
S
Weininger
J
J
Azoury
R
R
D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D005260:Female; D019786:Gadolinium DTPA; D007668:Kidney / Q000187:drug effects / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D009942:Organometallic Compounds / Q000494:pharmacology*; D004369:Pentetic Acid / Q000494:pharmacology*; D051381:Rats; D014667:Vasopressins / Q000494:pharmacology*; D014867:Water / Q000032:analysis*
D009942:Organometallic Compounds; D014867:Water; D014667:Vasopressins; D000804:Angiotensin II; D004369:Pentetic Acid; D019786:Gadolinium DTPA