REGULARITIES OF THE KINETICS OF GROWTH OF THE HEART MASS, LEFT VENTRICLE AND PARENCHYMA OF MYOCARD PRENATAL AND POSTNATAL ONTOGENESIS OF RATS

Zagoruyko Yu. V., Shmulich A. V., Zagoruiko G. E.

BIOLOGY

Scentific article

Wistar rats were used: 15-16 and 20-21 diurnal embryos, newborns, 5, 10, 15, 20, 25, 30, 35, 40, 45 day-old rats. Only 12 age groups. In each age group there were 5-10 individuals, mostly from the same litter. For further work, rats with body weight not exceeding 10-15% of the mean value for a group of animals were selected. After anesthesia in the rats, the heart was removed, which was placed in a filter on the ice to stop the heartbeat. The vessels were cut off, the chambers of the heart were released from blood clots. Isolated hearts were weighed (mсor, mg). Then, the atria were removed and the mass of the left ventricular wall was determined with an interventricular septum (ml, mg). From slices of LV of rats of different age half-thin sections were prepared. With microscopy of stained sections (1000x), the volume fraction (relative volume) of myocardial parenchyma (Vvpar, %) was determined using an ocular mesh (No = 225). It is established that the growth mass of the heart mcor = f1 (t) of the rat before and after birth has the form of an elongated letter “S”. For 45 days postnatal development of the rat, the heart mass increased 12 times, from 30 ± 5 mg to 360 ± 20 mg. The graph of the kinetics of the growth of the LV mass mlzh = f2 (t) also has the form of an elongated letter “S”. For 45 days of postnatal development of rats, the absolute mass of LV increased monotonically 24 times from 11.5 ± 2 mg (newborns) to 279.4 ± 25 mg, and the relative mass of the left ventricle increased by 2 times, from 38.5% to 77.6 %. Morphometric indices mL and Vvpar were used to determine the growth kinetics of the absolute mass of the myocardial parenchyma mpar = f3 (t) in the left ventricle of the rat heart of different ages. Calculations were carried out according to the formula: mpar = mł x Vvpar. It was found that for 45 days of postnatal development of rats, the mass of myocardial parenchyma in the LV increased monotonically 25 times, from 8.9 ± 2 mg to 223.5 ± 20 mg. Consequently, in the early periods of ontogeny of Wistar rats, monotonous growth of the mass of the heart, left ventricle and parenchyma of the myocardium of the LV is observed.

Wistar rats, ontogeny, heart, left ventricle (LV), left ventricular parenchyma

1. Gavrish AS. Stroyeniye serdechno-sosudistoy i limfaticheskoy sistemy. V kn. Rukovodstvo po kardiologii. K.: MORION; 2008. 1424 s. [in Russian].
2. Zhedenov VN. Legkiye i serdtse zhivotnykh i cheloveka. M.: Sovetskaya nauka; 1954. 206 s. [in Russian].
3. Puzik VI, Kharkov AA. Vozrastnaya morfologiya serdechno-sosudistoy sistemy cheloveka. M.: Medgiz; 1948. 210 s. [in Russian].
4. Roytberg GI. Vnutrenniye bolezni. Serdechno-sosudistaya sistema. M.: Binom-press; 2007. 856 s. [in Russian].
5. Antonyuk OP, Hnateyko OZ, Prokochuk NM. Suchasnyy stan pryrodzhenykh vad rozvytku lyudyny. Visnyk probl. biol. i medytsyny. 2016; 3(130):12-9. [in Ukrainian].
6. Frolkis VV, Muradyan HK. Eksperimentalnyye puti prodleniya zhizni. L.: Nauka; 1988. 248 s. [in Russian].
7. Frolkis VV. Stareniye serdtsa. Kardiologiya. 1991;1:8-10. [in Russian].
8. Rumyantsev PP. Kardiomiotsity v protsessakh reproduktsii, differentsirovki i regeneratsii. L.: Nauka; 1982. 288 s. [in Russian].
9. Kozlov VA, Tverdokhleb IV, Shponka IS, Mishalov VD. Morfologiya razvivayushchegosya serdtsa. Struktura, ultrastruktura, metabolizm. Dnepropetrovsk: DМА; 1995. 220 s. [in Russian].
10. Leu M, Ehler E, Perriard JC. Characterisation of postnatal growth of the murine heart. Brain structure and Function. 2001;204:217-24.
11. Prothero J. Heart weight as function of body weight in mammals. Growth. 1979;43:139-50.
12. Zagoruyko GYe, Zagoruyko YuV. Morfometricheskiy analiz prenatalnogo i postnatalnogo sozrevaniya kardiomiotsitov krys. Vísnik probl. bíol. í med. 2017;2(136):290-3. [in Russian].
13. Suslonova OV, Roshchevskaya IM, Rasputina AA. Morfometriya serdtsa zheludochkov krys linii NISAG v period rannego postnatalnogo razvitiya. Izvestiya Komi nauchnogo tsentra UrO RAN. 2016;1(25):44-50. [in Russian].
14. Gnatyuk MS, Tatarchuk LV, Prishlyak AM. Víkoví osoblivostí zmín yaderno-tsitoplazmatichnikh vídnoshen v kardíomíotsitakh sertsya doslídnikh tvarin. Tavrich. mediko-biol. vestnik. 2010;13(4):29-32. [in Ukrainian].
15. Nepomnyashchikh LM, Lushnikova YeL, Nepomnyashchikh GI. Morfometriya i stereologiya gipertrofii serdtsa Novosibirsk: Nauka. 1986. 304 s. [in Russian].
16. Zagoruyko GYe. Ranneye postnatal’noye razvitiye stromy miokarda krys. Arkhiv anatomii, gistologii i embriologii. 1989;97(11):5-8. [in Russian].

«Bulletin of problems biology and medicine» Issue 2 (144), 2018 year, 87-90 pages, index UDK 612.172 : 611.127-018

10.29254/2077-4214-2018-2-144-87-90