Biological Effect of Continuous, Quasi-Continuous and Pulsed Laser Radiation

Abstract

In this work, for the first time, comparative studies of biological activity of low intensity continuous, quasi-continuous and pulsed laser radiation of nano-and picosecond time ranges with the same average power density are carried out. It is shown, that, despite the significant differences in peak values of intensity of acting factor, both continuous and quasi-continuous radiation and radiation of nano-and picosecond ranges are able to have both stimulating and inhibiting effects on all investigated parameters of functional activity of biological systems in a certain range of dose rates.The ability of laser radiation of near infra-red spectral region (800 -1340 nm) located out the absorption bands of main chromophores of cells to have regulatory effect on biochemical processes that control the hatching of branchiopod crustaceans Artemia salina L. upon irradiation of their cysts is revealed. The role of molecular oxygen and water as acceptors of laser radiation is discussed.

Comparative Effect of Low‐intensity Laser Radiation in Green and Red Spectral Regions on Functional Characteristics of Sturgeon Sperm

“…The data on the photobiomodulation effect on the sperm using the radiation from laser and LED sources with other wavelengths in red spectral region (k = 620-630 (2,20-23), k = 630 nm (19), k = 635 nm (38), k = 637 nm (14), k = 647 nm (1), k = 650 nm (38), k = 655 nm (31,32), k = 660 nm (26,29), k = 670 nm (37)) can also be found in the literature. The effect of laser radiation in green spectral region (k = 532 nm) on spermatozoa is less studied (25,39). There are also few publications on the biomodulatory effect of radiation with other wavelengths in mentioned spectral region on sperm cells: k = 490-540 nm (34).…”

“…The following tests testifying to changes in the functional characteristics of spermatozoa as a result of exposure to laser radiation were chosen: (1) spermatozoa motility duration after 24 h cold storage (temperature 5°C) after activation; (2) the percentage of motile spermatozoa in sperm samples after 48 h cold storage; and (3) the fertilization rate (fertilization of eggs) after 48 h cold storage. The choice of above conditions for determining the photobiomodulation effect is due to both our (39) and literature (30) data indicating that, after cold storage for 24-48 h, the differences between the treated and control (untreated) samples of spermatozoa become more significant than immediately after the irradiation procedure.…”

“…Numerous studies performed with sperm from different species have shown that the radiation in visible spectral region (blue-green region: k = 470 nm (13), green: k = 532 nm (25,39), k = 490-540 nm (34); red: k = 620-630 (2,(20)(21)(22)(23), k = 630 (19), k = 632.8 (15,24,27,28,30,35,36), k = 635 nm (38), k = 637 nm (14), k = 647 nm (1), k = 650 nm (35), k = 655 nm (30,31), k = 660 nm (26,29), k = 670 nm (37)) and in near-infrared spectral region (k = 810 nm (16,19), k = 830 nm (12), k = 850 nm (14), k = 905 nm (11), k = 940 nm (10)), as well as broadband white light (k = 400-800 nm (17,18,27)), exerts a regulatory effect on spermatozoa.…”

“…At the present time, convincing evidences of the changes in the most important characteristics of spermatozoa exposed to light (motility, velocity, vitality, maintaining at a higher level the functional characteristics of spermatozoa during storage and their fertilization rate) have been obtained. The effects of photobiomodulation were reported upon irradiation of sperm from different species: mammals (human (1,(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19), boar (20)(21)(22), horse (2), donkey (23), bull (24)(25)(26)(27), ram (28,29), rabbit (30), dog (31,32), mouse (18,33,34)), birds (35,36) and hydrobionts (29,(37)(38)(39)(40). Changes in the functional characteristics of spermatozoa are induced by exposure to coherent laser radiation (1,9,11,12,15,16,19,(24)(25)…”

Biological Effect of Continuous, Quasi-Continuous and Pulsed Laser Radiation

“…Despite the progress in the practical use of low-intensity laser radiation in medicine and agriculture [1][2][3][4][5][6], question about mechanism of biological activity of mentioned physical factor is still open [2,4]. As a rule, the basic studies are carried out using a continuous radiation; biological effect of pulsed radiation of nano-and picosecond ranges is studied poorly.…”