José A. Palma

Evaluation of inflammatory biomarkers associated with oxidative stress and histological assessment of low-level laser therapy in experimental myopathy

The objective of the present work was to study the effect of helium–neon (He–Ne) and gallium–arsenide (Ga–As) laser upon inflammatory biomarkers associated with oxidative stress: fibrinogen, nitric oxide (NO), L‐citrulline, and superoxide dismutase (SOD). These were evaluated through histological assessment, in rats with experimental myopathy. Materials and Methods: The groups studied were: (A) control, (B) injured, (C) injured and treated with He–Ne laser, (D) injured and treated with Ga–As laser, (E) irradiated with He–Ne; and (F) irradiated with Ga–As laser. Myopathy was induced by injecting 0.05 mg/rat/day of adrenaline in the left posterior limb muscle at the same point on 5 consecutive days, in groups B, C, and D. Low‐level laser therapy (LLLT) was applied with 9.5 J/cm2 daily for 7 consecutive days with each laser. The determination of the biomarkers was made by spectrophotometry. The muscles (5/8, single blinded) were stained with Gomori Trichrome and examined by optic microscopy. The quantitative variables were statistically analyzed by the Fishers test and categorical data by the Axionvision 4.8 program. Pearsons chi‐squared test was applied, setting significant difference at P < 0.05 for all cases. Results: In group B, the biomarkers were significantly increased compared to the other groups (P < 0.001), except for NO which in group B decreased significantly (P < 0.001). In group B, there was a higher inflammatory infiltration level (80.67%) in relation to destroyed fibers. Conclusions: LLLT caused significant changes in inflammatory biomarkers and oxidative stress: decreased levels of fibrinogen, L‐citrulline and SOD as opposed to the increase of NO in rats with experimental myopathies and significant muscle recovery. Lasers Surg. Med. 42:577–583, 2010.

Interactions of prostaglandin E1, bradykinin and histamine and the increase of plasma fibrinogen in rats

Considering that tissue injury caused by laparotomy significantly increases the liver synthesis of plasma fibrinogen, and that PGE1, bradykinin and histamine are released into the injured tissues, the effect of above mentioned inflammatory agents and of the adrenal medulla on plasma fibrinogen levels in rats was studied. The subcutaneous administration of PGE1, bradykinin or histamine does not modify plasma fibrinogen levels acting independently comparing with non-injected animals or injected with the drug vehicle. Bradykinin + histamine did not modify plasma fibrinogen levels either. However the administration of prostaglandin E1 + bradykinin + histamine reproduced the increase of fibrinogen characteristics of laparotomy. This increase was partially but significantly inhibited in rats that had undergone bilateral removal of the adrenal medulla or administration of PGE1 + bradykinin + histamine + bupivacaine (a local anesthetic), but it was not modified when the adrenal medullectomy was unilateral. It is concluded that plasma fibrinogen increase is obtained only when PGE1 acts in presence of bradykinin or histamine and the adrenal medulla should be partially responsible for said increase.

Effects of diethylstilbestrol, 17 beta estradiol, and progesterone on plasma fibrinogen levels in rats submitted to tissue injury (laparotomy).

Participation of estrogens (17 beta estradiol, diethylstilbestrol) and progesterone in the increase of plasma fibrinogen levels in female rats submitted to tissue injury (laparotomy) was studied. Ovariectomy avoided the increase of fibrinogen observed in laparotomized rats, while the administration of 17 beta estradiol or diethylstilbestrol to laparotomized-ovariectomized rats increased fibrinogen to levels similar to those observed in the group of laparotomized rats without other treatment. On the other hand, progesterone inhibited the increase of fibrinogen which is typical of laparotomy in both groups: one of laparotomized rats and the other of laparotomized rats injected with estrogens. Neither estrogens nor progesterone modify plasma fibrinogen levels in uninjured rats. It is concluded that estrogens might participate in the fibrinogen increase observed after tissue injury in female rats, and on the contrary, the administration of progesterone would render that increase null.

Helium-neon effects of laser radiation in rats infected with thromboxane B 2

In previous investigations it was found that prostaglanding E1 (PGE1) and Bradiquinine (B), liberated in the inflammatory process, produced a significant increment on the Plasma fibrition Level (PFL), indicative of inflammatory process. The mentioned increment was completely abolished by the irradiation with HeNe laser in the area of infection of the mentioned substances. In the current investigation it was studied the effect of HeNe laser radiation on the P.F.L. of rats injected with another substance related with the inflammatory process and tissular injury: Thromboxane (Tx). It is though that the signal to increase P.F.L. is though an adrenal and an extra adrenal pathways. To study it we injected normal and medullectomized animals and both showed marked increment of P.F.L. Then we repeated the experiment but followed immediately by HeNe laser radiation and we noted a complete blockage of the P.F.L. increment in both groups which suggest that the effect is extra-adrenal. All substances were injected I.M. once daily X 3 days. Immediately after injection the area was irradiated with HeNe laser, 1.5 J total energy. In the normal, non injected non irradiated animals the P.F.L. reached 210.3 + 1.15 mg%. The single injection of Tx did not modify the P.F.L. compared with the previous group. The HeNe irradiation alone did not modify the P.F.L. in the animals injected with Tx only. The animals injected with PGE1+B showed a marked increment of P.F.L. to 337.6 + 14.5 mg%; the HeNe laser radiation completely abolished the increment (231 + 22.3 mg%). But in the animals injected with PGE1+B+Tx, the P.F.L. reached even larger values: 375.2 + 15.3 mg%. The HeNe laser radiation produced a partial blockage in P.F.L. increment (270.3 +/- 13.4 mg%). Showing a significant difference (p < 0.001) compared with normal rats or with rats injected with PGE1+B+Tx without radiation. In conclusion Tx potentiate the effect of PGE+B on the P.F.L. The HeNe laser blocks completely the interaction of PGE1+B on the P.F.L. but only partially the interaction PGE(subscript 1+B+Tx.

Na+-K+ Transport, Cotransport and Cell Volume of Rats Erythrocytes Submitted to Helium-Neon Laser Radiation

It has been studied the Na+-K+ transport, cotransport, and cell volume in erythrocytes of rats irradiated with Helium-Neon laser. It has been observed an increase in the passive diffusion of Na+ and K+ compensated by higher Na+-K+ pump activity. There was not observed alterations in Na+ and K+ cotransport, cell volume, as well as in the Na+ and K+ intracellular content.