Morphology

MD Idrisov A.A., Omarova S., T., Dosaev T. M., Aubakirov A. B.

Kazakh National Medical University after S. Asfendiyarov

Almaty, The Republic of Kazakhstan

STRUCTURAL CHANGES IN SPLEEN PARENCHYMA

UNDER EXPERIMENTAL ANHEPATIC PORTAL HYPERTENSION

The experimental animals: 100 outbred, sexually mature, female and male rats weighing 200 – 250 gr.

The control animals: 24 rats, false operated laparotomized without the portal vein constriction.

The experimental animals portal vein lumina was constricted at the place of the portal vein branching towards the lobes by ligation at two thirds of the initial size by the pattern under G. Celje.

Sampling was made on day 1, day 5, day 7, day 15, and day 30 after the operation date. The operation was made with etherization.

Histologicaly the spleen was studied on the preparations stained by hematoxylin and eosin, azur-2 and eosin by Van-Gizon.

Also, we made comparative analyses of morphological changes induced by experimental anhepatic portal hypertension with those of patients with portal hypertension syndrome under cirrhosis. The autopsy of 24 adult patients died of cirrhosis at the decompensation phase clinically diagnosed in Almaty Emergency Hospital was studied. As control there were 10 patients died suddenly of fatal traumas or of illnesses connected with neither abdominal cavity nor immune system abnormalities.

While analyzing the spleen preparations of the experimental animals under anhepatic portal hypertension by the day 1 we noticed that the structure of lymphoid nodules did not differ from those of the control animals. Only some areas of the spleen parenchyma showed extravasation centers and the sinus dilation.

By day 5 in contrast to day 1 in the lymphoid nodules of the spleen preparations of the experimental animals under anhepatic portal hypertension a mantle zone was observed more distinctly contouring the border between B-dependent zone and marginal zone. The marginal zone was identified in all lymphoid nodules in the form of a rim uniform in width and circling all B-dependent zone of all lymphoid nodules.

By day 7 of the experiment there was observed considerable dilation of the marginal zone of the lymphoid nodules and distinct borderline between B-dependent zone and marginal zone.

There were also visible dilated venous sinuses in the parenchyme surrounding a lymphoid nodule.

By day 15 of the experiment most of the lymphoid nodules were characterized by occurence of clear germinal centers which speaks about immunogenesis activation and further dilation of marginal zone of the lymphoid nodules. The marginal zones were dilated enough to contact each other at nearby lymphoid nodules and merging formed aggregates.

By day 30 in the spleen under portal hypertension there were discovered more considerable changes, namely, marginal zones size grew and most part of lymphoid nodules came to have germinal centers. Along all the parenchyma there were seen dilated venous sinuses.

But the most significant for that day was occurrence of large number of multinuclear cells of the kind of “a foreign body”.

Such multinuclear cells of the kind of “a foreign body” are absent in the control spleen of healthy rats. Neither they were discovered in the control examination and also by days 1, 5, 7 and 15 of portal hypertension.

Morphometric parameters statistical treatment of lymphoid nodules has revealed reliable (p<0,01) increase of lymphoid nodules size beginning from day 7 (Table 1) in proportion of anhepatic portal hypertension progress with animals and simultaneous considerable (р < 0,01) dilation of the marginal zone beginning form day 5 (Table 2).

Table 1 – Diameter (mkm) of the spleen lymphoid nodules under portal hypertension subject to the experiment period (М±m)

Diameter lymphoid nodules (mkm)	Period
	Control*	Day 1*	Day 5 *	Day 7**	Day 15**	Day 30**
	100,1±6,2	102,4±6,3	112±6,6	132±7,8	180±9,3	220±10,7

* – р > 0,05; ** – р < 0,01

Table 2 – Width (mkm) of the spleen lymphoid nodules marginal zones

under anhepatic portal hypertension

subject to the experiment period (М±m)

The marginal zone width (mkm)	Period
	Control*	Day 1*	Day 5 *	Day 7**	Day 15**	Day 30**
	16,5±1,4	19,2±1,6	28±2,04	33,1±2,2	37,8±2,5	45,9±2,3

* – р > 0,05; ** – р < 0,01

On the whole, due to lymphoid nodules diameter increase and the marginal zone dilation, volume density of white pulp has been substantially growing beginning from day 7 (p<0,01) and has grown twice by day 30 (Table 3).

Table 3 – Rat spleen white pulp volume density (Vv) under

anhepatic portal hypertension

subject to the experiment period (М±m)

Volume density (Vv)	Period
	Control*	Day 1*	Day 5 *	Day 7**	Day 15**	Day 30**
	24,3±0,7	25,5±0,6	26,8±0,8	35,8±1,6	50±2,7	55±3,2

* – р > 0,05; ** – р < 0,01

Among the data of morphometric parameters change of white pulp dynamics, dilation of lymphoid nodules marginal zone in proportion to portal hypertension progress is, in our opinion, of the most interest. It is explained by the fact that the marginal zone is an area on the borderline between red and white pulp where lymphocytes and macrophages come from blood and get first the information of antigens. Further they migrate into white pulp. Due to that the width of the marginal zone becomes a clear morphological criterion of immune state of an organism. [1].

References

1. Prasolova L. A., Oskina I. N., Shikhevich S. G. Morpho - functional characteristics of different reactions of a rat spleen after a restriction stress//Morphology (Saint Petersburg). - 2004. - 125, №1.- p .59-63.