Chronic renal insufficiency was modeled in rats by unilateral nephrectomy and electrocoagulation of both poles of the remaining kidney; acute renal failure was induced by 90-min clamping of the vascular pedicle of the only kidney. Injection of unfractionated culture of human fetal kidney cells or bone marrow mesenchymal stem cells into damaged kidney restored its function in rats with chronic renal insufficiency (observation period up to 2 months). After 2.5 months a relapse of chronic renal insufficiency was observed in 1 of 3 rats receiving human fetal kidney cells and in 1 of 2 animals receiving bone marrow mesenchymal stem cell culture. Injection of bone marrow mesenchymal stem cell culture to rats with acute renal failure improved recovery of renal function and prevented the death from uremia, while injection of total culture of human fetal kidney cells had virtually no effect on the course of acute renal failure.
Laser confocal microscopy showed that fluorescence of tetramethylrhodamine ethyl ether probe specifically accumulating in energized mitochondria significantly decreased in renal tubular epithelium after 40-min thermal ischemia, while fluorescence of dichlorodihydrofluorescein and diaminofluorescein probes in the same structures increased under these conditions, which attests to increased generation of ROS and NO, respectively. These forms were generated predominantly in mitochondria of tubular epitheliocytes. Hypoxic preconditioning (a series of sessions of breathing hypoxic mixture) preserved functional activity of mitochondria and prevented activation of ROS and NO generation. Ischemic preconditioning of the kidney consisting of three preliminary episodes of vascular clamping (5 min with 5 min reperfusion periods) also increased the percentage of functionally active mitochondria and prevented activation of NO synthesis without appreciably modifying ROS production. Both protective methods significantly reduced the severity of postischemic dysfunction of the kidney.
The therapeutic effect of intravenous injection of human fetal bone marrow mesenchymal stem cells or summary culture of kidney cells were studied on models of chronic or acute renal failure in outbred albino rats. Both cell types promoted improvement and normalization of the renal function in rats with stable chronic renal insufficiency (2 weeks after kidney cell injection, 1 month after bone marrow mesenchymal stem cell injection). Renal function remained normal or subnormal during the delayed period (3-3.5 months after injection). In rats with latent stage of chronic renal insufficiency, exacerbation was induced by additional 40-min ischemia. All rats receiving intravenous injection of saline died. Improvement of the functional parameters started 2 weeks after injection of kidney cells or bone marrow mesenchymal stem cells, and normalization was observed after 1.1-5 months. During the delayed period (after 3-4 months), functional parameters retained at normal or subnormal levels. In experimental series III, all rats with acute renal failure intravenously injected with saline (control) died from uremia on days 2-4. After injection of kidney cells 50% rats survived and renal function in these animals returned to normal after 2 weeks. After injection of bone marrow mesenchymal stem cells 83% rats survived, functional parameters returned to normal after 3 weeks.
Blood supply to the pelvic organs of outbred male rats was diminished by graduated constriction of the distal part of the inferior vena cava. Deficiency of intramural blood supply in prostate and urinary bladder was revealed by bioimpedance harmonic analysis according to the magnitude of first cardiac peak in the bioimpedance spectrogram. In 1-1.5 months, the histological examination revealed the glandular-stromal form of progressive benign prostatic hyperplasia in all ischemic rats. The development of hyperplasia was not accompanied by the changes in testosterone, dihydrotestosterone, or estradiol in blood and prostatic tissue. Assessment of vesical functional status by recording the intravesical pressure during infusion cystometry revealed an increase in the amplitude of spontaneous fluctuations of detrusor tone and intravesical pressure during bladder filling, which can be considered as indicator of detrusor hyperactivity. The data conclude that chronic ischemia of pelvic organs is an individual pathogenic factor in the development of benign prostatic hyperplasia and associated urinary disorders.
It is shown that in rats exposed to single external irradiation in a dose of 0.5 Gy the concentration of spermatozoa surpasses that of nonirradiated controls. The level of vitamin B 2 increases in the liver and testes of irradiated animals. For the given dose of ionizing radiation, the participation of angiotensin-converting enzyme in cell maturation during spermatogenesis is not observed. Various changes in the content of antioxidant vitamins at different stages of the experiment are described. Key Words: spermatozoa; irradiation; angiotensin-converting enzyme; vitamins; antioxidantsRadiation produces a variety of biological effects on mammals and men. Numerous studies demonstrated a dose-dependent effect of external irradiation on all systems of the organism. However, little is known on the mechanisms of this effect. Organism's response to irradiation include the repair processes. The efficiency of these processes has been little studied [8].The reproductive system, gonads, and cells of spermatogenesis are very sensitive to radiation. We previously described [3,4] the effect of irradiation on the reproductive system in Chernobyl cleanup workers. Analysis of spermograms revealed a rise of morphologically abnormal spermatozoa and the presence of numerous immature cells in ejaculate. At the same time, we found elevated activity of angiotensin converting enzyme (ACE) in spermatozoa, however, this phenomenon has not been explained. Taking into account that the Chernobyl workers were examined on average 4 years after irradiation (the mean dose in the group was 0.158 Gy), we decided to undertake an experimental study for evaluation of immediate effects of various doses of radiation. In the present study we explore changes in the intensity of spermatogenesis, ACE activity in spermatozoa, and the content of vitamins A, E, B 2, and B 6 in the testes, serum, and liver of mature rats exposed to external irradiation in a dose of 0.5 Gy. MATERIALS AND METHODSIrradiation was performed using an IGUR apparatus (Institute of Biophysics, Russian Academy of Medical Sciences): ~37Co emitter, 2.53 rad/sec power, 0.5 Gy (50 rad) dose, and 18 sec exposure. Age-matched animals served as the control.ACE activity was measured as described elsewhere [3]. Spermatozoa were counted as follows: epididymis homogenate in 10 ml physiological solution was centrifuged at 1500 rpm for 20 min, and the resultant sup.ernatant was centrifuged at 2000 rpm for 30 min. The sediment was resuspended in 1 ml buffer (pH 7.4), and the cells were counted in a Goryaev chamber (x200). In parallel, cells suspended in buffer containing a detergent phenylmethylsulfonyl fluoride were counted. It was shown that detergent did not increase ACE activity.For characterization of vitamin metabolism the following parameters were determined. Vitamin B2: riboflavin content in the testes and liver was mea-
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.