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Differential response of normal and cirrhotic liver to vasoactive agents. A study in the isolated perfused rat liver
160
OOUmnEN AND BASEMENT MEMBRANES DISTRIBUTION IN DIMEI"f]A~ITROSAMINE (DMN) INDUCED RAT L I 9 ~ C I P 2 / q O S I S RESEMBLE HUMAN PATHOLOGY PNIq'KW/qS. G. Ballardini, M. Fallani, R. Mancini*, M.L. Rinaldesi*t C. Venturini*, A.M. Jezequel*, F.B. Bianchi, E. Pisi. Cattedre di Semeiotica Medica e Clinica Medica II, Universita' di Bologna, e Istituto di Patologia Sperimentale$, Universita' di Ancona. D ~ , which is a b l e to i n d ~ e l i v e r fibrosis, was intraperitonea]ly injee_ted three times a week (1%, I0 pl/kg) to Sprague-Dawley male rats (200 g body weight). Groups of 3 treated and 3 saline injected rats were sacrificed after 7, 14 and 21 days and liver samples prepared for histological, immunohistological (snap frozen in liquid nitrogen cooled isopenthane) biochemical (liver collagen, as evaluated by hydroxyproline content) and electron microscopical (}~i) examination. The behaviour of connective tissue components (collagens type I, III, IV, laminin-L, fibronectin-F, heperan sulphate proteoglycan-HSPg) and desmin, as a marker for Ire cells, was studied by indirect IFL. Uncomplete fibrous sepia appeared after 7 days and surrounded the complex Rappaport acinus after 14-21 days. Ito cells were higly represented within septa. Collagen content increased from 1.86 (median) in controls, to 3.04, 5.11, 8.35 mg/100 mg proteins after 7, 14 and 21 days respectively. F and HSPg firstly increased in septa and periseptal sinusoids, followed by type Ill and l collagens. In advanced cases limiting lamina was interrupted and isolated hepatocytes were surrounded by collagens (pericellular fibrosis) and L (suggesting the appearence of basement membranes). An increased collagen deposition was observed within the residual parenchima along with a rearrangement of hepatocellular laminas with formation of multicellular plates, reduction of sinusoidal surface (evaluated by sinusoidal type IV collagen positivity) and appearance of sinusoidal capillarization (presence of L and }~M demonstration of basement membranes). Unlike other exqoerimental models, this closely reproduces alterations co,mlonly found in human chronic active hepatitis and cirrhosis; for this reason it seems of interest in the study of liver fibrosis and possibly liver disfunction.
161
DIFFERENTIAL RESPONSE OF NORMAL AND CIRRHOTIC LIVER TO VASOACTIVE AGENTS. A STUDY IN THE ISOLATED PERFUSED RAT LIVER. F. BALLET, Y. CHRETIEN, C. REY, R. POUPON. Unitd d'Hdpatologie INSERM, HSpital Saint-Antoine, Paris, FRANCE.
In cirrhosis, endogenous vasoactive agents could act as modulators of intrahepatic portal resistance (R) and thus, portal pressure (P). The aim of this work was to study the effects of norepinephrine (NE), angiotensin II (AN) and argS-vasopressin (VP) on R in isolated perfused livers from normal and CCI~ -induced cirrhotic rats. Livers were perfused at a constant P and the measured variable was portal blood flow (Q). R was calculated as R = P/Q. Dose-response curves were obtained by cumulative addition of agonists to the perfusate. The maximal effect (Emax) and the molar concentration at Emax/2 (ED50) were derived from individual dose-response curves fitted to a logistic function . Results are below : Emax (dyn.s.cm-S. 10 ~)
controls cirrhosis
NE 9.61 ± 1.52 12.04 ± 3.05
AN 4.14 ± 0.59 5.11 ± 0.99
VP 0.47± 0.07 0.99±0.35
ED50 controls 3.38 ± 0.66.10-6, 4.11 ± 0.81.10-9,, 2.05± 0.82.10-9 (M) cirrhosis 1.43 ± 0.37 10-6 1.24 ± 0.09.10- e 2.57± 1.49.10- 9 (* P < 0.05, ** P < 0.001); (mean ~ SE) Emax was not significantly different in normal and cirrhotic livers. The cirrhotic livers exhibited an increased sensitivity to NE, a decreased sensitivity to AN but an unchanged sensitivity to VP. We conclude that there is a modulable component in the portal vasculature of cirrhotic livers that retains a strong vascular reactivity to vasoactive agonists, particularly to NE.
$86
OOUmnEN AND BASEMENT MEMBRANES DISTRIBUTION IN DIMEI"f]A~ITROSAMINE (DMN) INDUCED RAT L I 9 ~ C I P 2 / q O S I S RESEMBLE HUMAN PATHOLOGY PNIq'KW/qS. G. Ballardini, M. Fallani, R. Mancini*, M.L. Rinaldesi*t C. Venturini*, A.M. Jezequel*, F.B. Bianchi, E. Pisi. Cattedre di Semeiotica Medica e Clinica Medica II, Universita' di Bologna, e Istituto di Patologia Sperimentale$, Universita' di Ancona. D ~ , which is a b l e to i n d ~ e l i v e r fibrosis, was intraperitonea]ly injee_ted three times a week (1%, I0 pl/kg) to Sprague-Dawley male rats (200 g body weight). Groups of 3 treated and 3 saline injected rats were sacrificed after 7, 14 and 21 days and liver samples prepared for histological, immunohistological (snap frozen in liquid nitrogen cooled isopenthane) biochemical (liver collagen, as evaluated by hydroxyproline content) and electron microscopical (}~i) examination. The behaviour of connective tissue components (collagens type I, III, IV, laminin-L, fibronectin-F, heperan sulphate proteoglycan-HSPg) and desmin, as a marker for Ire cells, was studied by indirect IFL. Uncomplete fibrous sepia appeared after 7 days and surrounded the complex Rappaport acinus after 14-21 days. Ito cells were higly represented within septa. Collagen content increased from 1.86 (median) in controls, to 3.04, 5.11, 8.35 mg/100 mg proteins after 7, 14 and 21 days respectively. F and HSPg firstly increased in septa and periseptal sinusoids, followed by type Ill and l collagens. In advanced cases limiting lamina was interrupted and isolated hepatocytes were surrounded by collagens (pericellular fibrosis) and L (suggesting the appearence of basement membranes). An increased collagen deposition was observed within the residual parenchima along with a rearrangement of hepatocellular laminas with formation of multicellular plates, reduction of sinusoidal surface (evaluated by sinusoidal type IV collagen positivity) and appearance of sinusoidal capillarization (presence of L and }~M demonstration of basement membranes). Unlike other exqoerimental models, this closely reproduces alterations co,mlonly found in human chronic active hepatitis and cirrhosis; for this reason it seems of interest in the study of liver fibrosis and possibly liver disfunction.
161
DIFFERENTIAL RESPONSE OF NORMAL AND CIRRHOTIC LIVER TO VASOACTIVE AGENTS. A STUDY IN THE ISOLATED PERFUSED RAT LIVER. F. BALLET, Y. CHRETIEN, C. REY, R. POUPON. Unitd d'Hdpatologie INSERM, HSpital Saint-Antoine, Paris, FRANCE.
In cirrhosis, endogenous vasoactive agents could act as modulators of intrahepatic portal resistance (R) and thus, portal pressure (P). The aim of this work was to study the effects of norepinephrine (NE), angiotensin II (AN) and argS-vasopressin (VP) on R in isolated perfused livers from normal and CCI~ -induced cirrhotic rats. Livers were perfused at a constant P and the measured variable was portal blood flow (Q). R was calculated as R = P/Q. Dose-response curves were obtained by cumulative addition of agonists to the perfusate. The maximal effect (Emax) and the molar concentration at Emax/2 (ED50) were derived from individual dose-response curves fitted to a logistic function . Results are below : Emax (dyn.s.cm-S. 10 ~)
controls cirrhosis
NE 9.61 ± 1.52 12.04 ± 3.05
AN 4.14 ± 0.59 5.11 ± 0.99
VP 0.47± 0.07 0.99±0.35
ED50 controls 3.38 ± 0.66.10-6, 4.11 ± 0.81.10-9,, 2.05± 0.82.10-9 (M) cirrhosis 1.43 ± 0.37 10-6 1.24 ± 0.09.10- e 2.57± 1.49.10- 9 (* P < 0.05, ** P < 0.001); (mean ~ SE) Emax was not significantly different in normal and cirrhotic livers. The cirrhotic livers exhibited an increased sensitivity to NE, a decreased sensitivity to AN but an unchanged sensitivity to VP. We conclude that there is a modulable component in the portal vasculature of cirrhotic livers that retains a strong vascular reactivity to vasoactive agonists, particularly to NE.
$86