[INFLUENCE OF THE FEMALE SEX HORMONE 17-BETA-ESTRADIOL ON THE DEGREE OF HYPOXIC PULMONARY HYPERTENSION IN MALE AND FEMALE WISTAR RATS.]

The influence of endogenous and exogenous 17-beta-estradiol on the degree of hypoxic pulmonary hypertension (HPH) in male and female Wistar rats has been studied. Endogenous estradiol reduced the right ventricular systolic pressure (RVSP) in normal female rats, but not in male rats. Exogenous estradiol (15 pg/kg for 4 weeks) caused the same effect. The HPH was induced by exposure to intermittent hypobaric hypoxia (10 h a day, 02 = 10%). Two weeks after hypoxia exposure, increased RVSP was more developed in females as compared to males. Comparison of RVSP between hypertensive and normotensive fet'a- le groups showed that the pathology in hypertensive females with retained ovaries is developed more than in ovariectomized ones. Exogenous estradiol exhibi- ted no protective effect in hypoxic ovariectomized female rats. In males, the ovariectomy did not influence the RVSP level, but caused hypertrophy of the right ventricle. In this case, exogenous estradiol led to an increase in RVSP. Thus, endogenous 17-beta-estradiol has a protective effect on the pulmonary blood flow in normal females. In the case of hypoxic pulmonary hypertension, endogenous estradiol enhances the development of this pathology in females and ovariecto- mized males.

[Characteristics of an interspecies somatic hybrid (Chinese hamster X mouse)]. / Osobennosti mezhvidovogo somaticheskogo gibrida (kitaiskii khomiachokXmysh').

An interspecific somatic hybrid between the biochemically marked cell lines of Chinese hamster (M-15-1) and mouse (B-82) was obtained. Morphology of the hybrid, its karyotype characteristics in the 9-th and 22-nd passages, as well as kinetics of growth were studied. Periods of doubling of the hybrid cells, the Chinese hamster M-15-1 cells and the mouse B-82 cells proved to be 26, 18 and 21 h, respectively. It was revealed, that elimination of chromosomes took place in the course of the hybrid cells reproduction at the expense of two-arm chromosomes of both parental lines.

[Biochemically labelled human lymphoblastoid cell line. I. Its karyotypic, growth and physiological characteristics]. / Biokhimicheski markirovannaia limfoblastoidnaia liniia kletok cheloveka. I. Kariotipicheskaia, rostovye i fiziologicheskie kharakteristiki.

A study was made of the properties of human lymphoid cell line RPMI-6410 derived from peripheral blood of a patient with acute myeloblastic leukaemia. The lymphoblastoid cell line was found to be resistant to 5-brom-deoxyuridine and to have a low thymidine kinase activity. The modal chromosome number for RPMI-6410 is 46-47 XY. The karyotype includes marker chromosomes: two large submetacentrics --M1 and M2, and two small acrocentrics--M3 and M4. Ways of marker chromosome formation are discussed. The properties of RPMI-6410 line make it possible to use it for somatic cell hybridization, in particular, for obtaining hybridoma synthesizing human monoclonal antibodies.

[Chinese hamster cell mutant at the hypoxanthine-guanine phosphoribosyltransferase locus. I. The collection of mutants and intragene complementation experiments]. / Issledovanie kletok kitaiskogo khomiachka, mutantnykh po lokusu gipoksantin-guaninfosforiboziltransferazy. Soobshchenie I. Kollektsiia mutantov i éksperimenty po vnutrigennoi komplementatsii.

A group of 59 Chinese hamster cell clones mutant for hypoxanthine-guanine phosphoribozyl-transferase (HGPRT) is described. The clones were collected from selective media containing three purine analogs, 8-azaguanine, 6-mercaptopurine and 6-thioguanine. Spontaneous mutants of an independent origin induced by different mutagens were studied. They differed by the degree of the HGPRT enzyme activity and their ability to grow in the presence of purine analogs and on a counter-selective HAT medium. Mutant clones showed "abnormal" combinations of resistance to both types of selective media and also lacked cross-resistance to different analogs of hypoxanthine and guanine. A possibility of intragenics complementation between various clones was studied. The scheme of experiments on complementation is proposed to make the work less time-consuming by virtue of a simultaneous testing of a clone group. Having used the method, 383 clone combinations were analyzed and 13 complementing pairs of mutants. were found.