[Changes in the diameter and length of hypertrophic cardiomyocytes in the dilated left ventricle of cardiac surgical patients]. / Izmenenie diametra i dliny gipertrofirovannykh kardiomiotsitov dilatirovannogo levogo zheludochka u kardiokhirurgicheskikh bol'nykh.

AIM: to investigate changes in the diameter and length of hypertrophic cardiomyocytes (CMCs) in the dilated left ventricle (LV). SUBJECTS AND METHODS: Light microscopy, morphometry, and statistical analysis were used to investigate the status of the contractile apparatus and changes in the length, diameter of CHC and diameter of CMC nuclei, by using intraoperative dilated LV biopsy samples from 31 patients with valvular disorders and dilated cardiomyopathy. Morphological findings were compared with the clinical parameters of the patients. RESULTS: CMCs in the patients with the dilated LV were hypertrophic and were at different stages of restructuring with progressive myofibrillar loss (PML). In 81% of patients, the diameter of CMCs was not significantly changed as their zones of PML extended. The length of CMCs, which correlated with the enlarged LV cavity, was increased in 52% of patients during cell restructuring with PML. In 42% of patients, the CMC nuclear diameter increased during restructuring with PML, which appeared to be associated with CMC polyploidization; in some of these patients (19% of the total number of patients), the diameter of CMCs increased in parallel with the higher diameter of their nuclei. CONCLUSION: The findings suggest that after completion of their transverse growth, hypertrophic CMCs are involved in a restructuring process with PML. The findings are consistent with the hypothesis that dilatation of the hypertrophied LV cavity is related to the preferential elongation of CMCs with an inadequate increase in their diameter. The results of the investigation may assume that the higher CMC diameter that brings to completion before the entry of the cells into the restructuring process with PML, resumes in the cells, the ploidy of which increases in the course of restructuring with PML, triggering an additional mechanism for raising the CMC diameter at this stage of myocardial hypertrophy. The results are indicative of different mechanisms for increasing the diameter and length of hypertrophic CMCs, since the diameter of CMCs directly correlates with that of their nuclei, and the length increases as the zones of PML extend in the CMCs.

[Morphometric features of cardiomyocytes in the ventricular septum of patients with hypertrophic cardiomyopathy]. / Morfometricheskie osobennosti kardiomiotsitov mezhzheludochkovoi peregorodki u bol'nykh gipertroficheskoi kardiomiopatiei.

AIM: to determine the diameter and length of cardiomyocytes (CMC) in the ventricular septum (VS) of patients with hypertrophic cardiomyopathy (HCM) and to analyze correlations of a change in CMC sizes with the anatomical features of the heart in the patients. MATERIAL AND METHODS: Longitudinal sections of intraoperative myocardial biopsy specimens taken from 23 patients aged 15-59 years with HCM were treated using immunohistochemical detection of connexin 43; the sizes of 50 CMCs were measured; a 4-point scale was used to assess the degree of myofibril loss (MFL) in these cells. The change in the diameter and length of the cells during their rearrangement as MFL gradually increased, as well as the correlations of CMC sizes with the anatomical parameters of the heart were analyzed. RESULTS: VS CMCs from the patients with HCM were hypertrophic and were in the early stages of rearrangement accompanied by MFL. During this rearrangement, CMCs in some patients grew in length and, less frequently, diameter. The average diameter of CMCs was directly correlated with VS thickness. The average length of the cells in the CMC population with a considerable degree of MFL also directly correlated with VS thickness. CONCLUSION: The findings could suggest that the factor raising VS thickness in HCM may be an increase in not only diameter of CMCs, but also in length of CMCs, which had impaired orientation in the VS - which are oriented perpendicular to their normal tangential position. The presence of such CMCs in the VS myocardium in patients with HCM can be discussed due to the typical large number of myocardial areas with the impaired parallel arrangement of CMCs.

[Effectiveness of protecting the myocardium against ischemia with a normothermic cardioplegic solution and creatine phosphate]. / Effektivnost' zashchity miokarda ot ishemii normotermicheskim kardioplegicheskim rastvorom s kreatinfosfatom.

The protective effects of cardioplegic solutions (CS) containing creatine phosphate (CP) were studied in a rat heart model of cardiopulmonary bypass and ischemic cardiac arrest. Isolated rat hearts were subjected to a 3-minute coronary infusion with CS containing CP in normothermic (37 degrees C) and hypothermic (4-6 degrees C) regimes. In the normothermia group, the postischemic functional recovery was 70-75% of the preischemic control value, while the cellular ATP and CP content was reduced but insignificantly. By contrast, in the hypothermia group, the postischemic functional recovery was markedly depressed, with the tissue high-energy phosphate content being appreciably lowered. The data obtained confirm high efficacy of CP-containing cardioplegic solutions administered under normothermia conditions.

[Incorporation of labeled sex hormones into the ependyma of the mediobasal hypothalamus of rats after intraperitoneal and intraventricular administration]. / Vkliuchenie mechenykh polovykh gormonov v ependimu mediobazal'nogo gipotalamusa krys posle vnutribriushinnogo i vnutrizheludochkovogo ikh vvedeniia.

Histoautoradiography was used to demonstrate the ability of ependyma element of the 3d brain ventricle to incorporate the label after intraperitoneal and intraventricular injection of labeled sexual hormones. The least label incorporation after intraventricular injection of 3H-estradiol and 3H-testosterone and the maximal label incorporation after intraperitoneal injection of 3H-estradiol was demonstrated by beta 1-tanicytes. The basal processes of these cells terminate in the lateral part of the external zone of the median eminence where gonadoliberin is released to the portal capillaries of the hypophysis. The data obtained warrant an assumption that beta 1-tanicytes are responsible for the transport of sexual hormones primarily from the pericapillary space of the median eminence of the hypothalamus to the cerebrospinal fluid, thereby possibly taking part in the regulation of gonadoliberin release to the portal circulation of the hypophysis.

[Incorporation of 3H-estradiol into elements of the tanycytic and ciliated ependyma of the 3d cerebral ventricle in experiments in vitro]. / Vkliuchenie 3H-éstradiola v élementy tanitsitarnoi i resnichnoi épendimy III zheludochka mozga v opytakh in vitro.

The label incorporation into the arcuate nucleus neurons, the tanicytic and ciliary ependyma of the mediobasal hypotahalamus, and also into the underlying nerve tissue after in vitro incubation of male Wistar rats hypothalamic tissue in the presence of 3H-estradiol was studied autoradiographically. After incubation at 37 degrees C, along with the nuclear localization of the label in the neutrons of the arcuate nucleus, characteristic of estradiol, high radioactivity was revealed in tanicytes; the label incorporation into beta-tanicytes was always higher than into the alpha2-tanicytes. Subsequent incubation of the tissue with nonlabeled estradiol led to reduction of beta-tanicytes radioactivity; as to ciliary ependyma and alpha2-tanicytes radioactivity--it rose. Reduction of incubation temperature to 22 degrees C failed to alter the character of the label incorporation into tanicytes. The data obtained confirmed the possibility of participation of the mediobasal hypothalamus tanicytes in the realization of the estradiol action of the hypothalamus.