HISTOLOGICAL LOCALIZATION 



OF FLUORESCENT SERUM PROTEINS 



AND THYROID-STIMULATING HORMONE 



IN THE CONNECTIVE TISSUE OF THE RAT 



R. E. MANCINI, 0. VILAR, J. M. DELLACHA, 0. W. DAVIDSON 



and B. ALVAREZ 



Instituto de Anatomîa General y Embriologia, Facultad de Medicina, 



Buenos Aires, Argentina 



Rat total sérum, albumin, globulins and fibrinogen (native or denaturated) 

 were labeled with a fluorescent dye (Lissamine-Rhodamine B 200) follow- 

 ing Chadwick's method with slight modifications. Changes in the nature 

 of thèse proteins were checked by paper electrophoresis and anaphylactic 

 shock in guinea-pigs. 



Several Armour and U.S. Public Health pituitary hormones préparations 

 (TSH, FSH, LH, ACTII, MSH, STII and Prolactin) active and denaturated, 

 were labeled with the same fluorescent dye. The amount of dye bound to 

 thèse proteins and hormones was spectro-photometrically determined. 

 Changes in the biological activity of some of thèse hormones were check- 

 ed using biological methods. 



Labeled sérum proteins or hormones were i.v. injected in rats or mice 

 and the animais were killed between three minutes and twelve days. 

 Blood and urine samples were taken just before sacrifice for measuring 

 the decay of the labeled proteins and hormones in the circulation and its 

 élimination by the kidney. As a control, another lot of rats were injected 

 with Lissamine-Rhodamine solutions alone. AU tissues were fixed in 

 buffered formalin and frozen or paraffin sections examined with the fluo- 

 rescence microscope. 



It was observed: 1) the decay of sérum proteins in the circulation 

 showed a fast and a slow component. The first is correlated with the 

 présence of fluorescent proteins in the lumen and wall of the capillaries 

 and then trasppassing the vessels in the neighboring connective tissue 

 of différent organs (capsules, septa, interstitium, basai membranes, 

 tendons, perichondrium). The slow component of the curve is correlated 



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