[Influence of Malignant Growth and Chronic Neurogenic Pain on Neurosteroid Levels in Rat Brain]

The aim of the study was to determine the level of sex steroid hormones in white matter of the brain of rats with tumors combined with chronic neurogenic pain (CNP), which was modeled by bilateral sciatic nerve ligation. The study included albino male rats (n=74). In the main group, M1 sarcoma was transplanted subcutaneously (n=11) or into the subclavian vein (n=11) 45 days after CNP modeling. Two comparison groups (n=13 each) included sham operated animals (without CNP) with M1 sarcoma transplanted subcutaneously and intravenously. Control groups included animals with CNP and sham operated animals. Rats were euthanized on day 21 of the carcinogenesis. Levels of total and free testosterone (T), estrone (E1), estradiol (E2), estriol (E3) and progesterone (P4) in the brain white matter were measured using ELISA kits ("Cusabio", China). CNP caused a decrease in the total and free T by 1.5 times (p<0.05), E2 and P4 by 1.9 and 3 times, respectively, E3 by 1.6 times (p<0.05), as well as an increase in E1 by 1.4 times (p<0.05) as compared to the corresponding levels in the brain white matter of rats without CNP. CNP stimulated M1 sarcoma growth in both subcutaneous and intravenous transplantation. Regardless of the tumor site, the dynamics of total T, E2 and E3 in the brain had similar features, but the dynamics of free T, P4 and E1 differed. Thus, changes in the level of neurosteroids in the white matter of rat brain with CNP and tumor growth alone or associated with CNP are a reaction to stress.

Issledovali soderzhanie polovykh steroidnykh gormonov v belom veshchestve golovnogo mozga krys pri zlokachestvennom protsesse, sopriazhennom s khronicheskoĭ neĭrogennoĭ bol'iu (KhNB), kotoruiu modelirovali putem dvustoronneĭ pereviazki sedalishchnykh nervov. Rabota vypolnena na samtsakh belykh besporodnykh krys (n=74). V osnovnoĭ gruppe zhivotnym cherez 45 dneĭ posle modelirovaniia KhNB perevivali sarkomu M1 podkozhno (n=11) ili v podkliuchichnuiu venu (n=11). Dve gruppy sravneniia (v kazhdoĭ po 13 krys) – lozhno operirovannye zhivotnye s perevivkoĭ sarkomy M1 podkozhno i vnutrivenno, no bez KhNB. Kontrol'nye gruppy – zhivotnye s KhNB i lozhno operirovannye zhivotnye. Évtanaziiu proizvodili na 21 den' kantserogeneza. V belom veshchestve golovnogo mozga opredeliali soderzhanie obshchego i svobodnogo testosterona (T), éstrona (E1), éstradiola (E2), éstriola (E3) i progesterona (R4). KhNB vyzyvaet snizhenie obshchego i svobodnogo T v srednem v 1,5 raza (p<0,05), E2 i R4 v 1,9 raza i 3 raza sootvetstvenno (p<0,05), E3 v 1,6 raza (p<0,05) i povyshenie urovnia E1 v 1,4 raza (p<0,05) otnositel'no urovnia v belom veshchestve mozga krys bez KhNB. Vyiavleno, chto KhNB stimuliruet rost sarkomy M1 kak pri traditsionnoĭ podkozhnoĭ, tak i pri vnutrivennoĭ perevivke. Nezavisimo ot lokalizatsii opukholevogo rosta dinamika urovneĭ obshchego T, E2 i E3 v mozge imela skhozhie cherty, odnako dinamika urovneĭ svobodnogo T, R4 i E1 razlichalas'. Takim obrazom, obnaruzhennye izmeneniia urovnia neĭrosteroidov v belom veshchestve mozga krys pri KhNB i opukholevom roste v samostoiatel'nom vide ili sopriazhennom s KhNB iavliaiutsia reaktsieĭ na stressornoe vozdeĭstvie.

Keywords: M1 sarcoma; brain; chronic neurogenic pain; rats; sex steroid hormones.