Circadian effects of ionizing radiation on reproductive function and clock genes expression in male mouse

BACKGROUND@#Exposure to the ionizing radiation (IR) encountered outside the magnetic field of the Earth poses a persistent threat to the reproductive functions of astronauts. The potential effects of space IR on the circadian rhythms of male reproductive functions have not been well characterized so far.@*METHODS@#Here, we investigated the circadian effects of IR exposure (3 Gy X-rays) on reproductive functional markers in mouse testicular tissue and epididymis at regular intervals over a 24-h day. For each animal, epididymis was tested for sperm motility, and the testis tissue was used for daily sperm production (DSP), testosterone levels, and activities of testicular enzymes (glucose-6-phosphate dehydrogenase (G6PDH), sorbitol dehydrogenase (SDH), lactic dehydrogenase (LDH), and acid phosphatase (ACP)), and the clock genes mRNA expression such as Clock, Bmal1, Ror-α, Ror-β, or Ror-γ.@*RESULTS@#Mice exposed to IR exhibited a disruption in circadian rhythms of reproductive markers, as indicated by decreased sperm motility, increased daily sperm production (DSP), and reduced activities of testis enzymes such as G6PDH, SDH, LDH, and ACP. Moreover, IR exposure also decreased mRNA expression of five clock genes (Clock, Bmal1, Ror-α, Ror-β, or Ror-γ) in testis, with alteration in the rhythm parameters.@*CONCLUSION@#These findings suggested potential health effects of IR exposure on reproductive functions of male astronauts, in terms of both the daily overall level as well as the circadian rhythmicity.

Effects of glucose concentration fluctuation on function of cultured bovine arterial endothelial cells / 中华心血管病杂志

<p><b>OBJECTIVE</b>To explore the effects of glucose concentration fluctuation on function of cultured bovine arterial endothelial cells and underlying mechanism.</p><p><b>METHODS</b>The thoracic aorta of newborn calf was used for primary endothelial cells culture. Cells were divided into 3 groups and cultured for 48 h: control group (C, 5.5 mmol/L), constant high glucose group (HG, 30 mmol/L) and glucose fluctuation (GF, three circles of 2 h 30 mmol/L followed by 3 h 5.5 mmol/L, 30 mmol/L overnight, repeat the whole procedure on the following day) groups. The membranes fluidity of endothelial cells was detected by fluorescence polarization method. The contents of sorbierite, aldose reductase (AR), sorbitol dehydrogenase (SDH) and advanced glycation end products (AGEs) were measured. RAGE, eNOS and ET-1 mRNA expressions were detected by semi-quantitative RT-PCR.</p><p><b>RESULTS</b>The membranes fluidity of endothelial cells in HG or GF group were significantly decreased compared with the control group (all P < 0.01) and significantly lower in GF group than those in HG group (all P < 0.01). Sorbierite, AR and AGEs concentrations were significantly higher in HG and GF groups than those in control group (all P < 0.01) and AR and AGEs concentrations were significantly higher in GF group than that in HG group (all P < 0.01). SDH of endothelial cells in HG or GF group were decreased compared with the control group and lower in GF group than in HG group (all P < 0.05). In addition, the mRNA levels of RAGE, eNOS and ET-1 were significantly upregulated compared with the control group (all P < 0.01).</p><p><b>CONCLUSIONS</b>Glucose concentration fluctuation can result in more severe bovine arterial endothelial cells dysfunction than high glucose via activating polyols metabolic pathways, upregulating the expression of AGEs, eNOS and ET-1. Therefore, glucose concentration fluctuation might play a crucial role on macrovascular complications of diabetes.</p>

Effect of dibutyl phthalate on the biochemical enzymes and lipid peroxidation in rat testes / 中华男科学杂志

<p><b>OBJECTIVE</b>To explore the effect of dibutyl phthalate (DBP) on the biochemical enzymes and lipid peroxidation in rats.</p><p><b>METHODS</b>Healthy 6-week old male Sprague-Dawley rats were randomly divided into 4 groups with 16 in each. DBP dissolved in peanut oil was administered by gavage at dosages of 0, 250, 500 and 1000 mg/(kg x d). After 2- and 4-week DBP exposure, 8 rats in each group were killed, with certain organs selected and weighed. The activities of biochemical enzymes and glutathione peroxidase (GSH-Px) and the levels of glutathione (GSH) in the serum and testis homogenate were determined respectively.</p><p><b>RESULTS</b>DBP induced a rise in the liver organ body weight ratio, but a fall in the testis organ body weight ratio, and it was significant in the highest exposure group compared with the control after either 2-week or 4-week treatment (P < 0.01). After 2-week DBP exposure, GSHPx activities in the serum and GSH levels in the testis homogenate showed a decreasing tendency, but GSHPx activities increased markedly in the testis homogenate (P < 0.05). After 4-week DBP exposure, while alkaline phosphatase (ALP) activities in the serum revealed an increasing tendency, sorbitol dehydrogenase (SDH) activities were inhibited significantly in both the serum and the testis homogenate at the dosage of 1000 mg/(kg x d) compared with the control group (P < 0.01). Furthermore, GSH contents in the serum were also affected at this dose (P < 0.05).</p><p><b>CONCLUSION</b>The results indicate that DBP administration strongly affects the liver and the testis organ body weight ratios. Lipid peroxidation is one possible toxic mechanism caused by DBP. SDH may be one of the most sensitive toxic indices when exposed to DBP.</p>

Melatonin: the assumed latest cure- all drug

This study was carried out to evaluate the hormonal and some biochemical changes which might be caused by administration of melatonin [Mt] daily for five months to 36 albino rats of both sexes. Long-term administration of doses equivalent to human dose range of melatonin caused an increase in testosterone, a decrease in estradiol [E2] levels in males with no change in the levels of both hormones in females, an increase in follicular stimulating hormones [FSH] and luteinizing hormone [LH] and a decrease in prolactin [PRL] levels in both sexes. Serum glutamicoxalo-acetic transaminase [GOT], glutamic- pyruvic transaminase [GPT] and sorbitol dehydrogenase [SDH] showed a significant increase from the third month onwards, while serum urea and creatinine showed a significant increase only at the fifth month

Testicular lactate dehydrogenase and sorbitol dehydrogenase activity after intratesticular injection of dynorphin and morphine in male rats.

Testicular lactate dehydrogenase (LDH) and sorbitol dehydrogenase (SDH) activity were measured at 1 and 4 hr following intratesticular injection of morphine and dynorphin. Twenty five and 50 micrograms doses of morphine sulfate significantly reduced LDH activity at 1 hr after injection. Five and 25 micrograms doses of dynorphin reduced LDH activity both at 1 and 4 hr after treatment. Testicular SDH activity was increased by morphine at 1 hr followed by a decrease at 4 hr. Both doses of dynorphin significantly reduced SDH activity at 1 and 4 hr after treatment. These results indicate paracrine regulatory role for opioids in testicular metabolism.

Vitamins prevention of diabetic complication: effect of vitamins C and B6 on glycosylated hemoglobin and sorbitol dehydrogenase

The experiments were undertaken to assess the role of vitamin C [ascorbic acid] and vitamin B6 [pyridoxine] in relation to sorbitol dehydrogenase activity and glycosylated hemoglobin levels in sorbitol pathway linked neural and vascular dysfunction and nonenzymatic glycosylation in rats with alloxan induced diabetes. Vitamins C and B6 monotherapy were given orally to control and diabetic rats. After 30 days and 45 days of treatment, glycosylated hemoglobin levels were decreased significantly [p <0.05 to 0.001]. Sorbitol dehydrogenase activity in normal rats during vitamin C therapy were increased significantly [p <0.08 to 0.001] from 7 to 9 folds after 30 days and 45 days, respectively. In diabetic rats sorbitol dehydrogenase activity elevated about 2.5 folds. Vitamin B6 increased sorbitol dehydrogenase activity about 7 folds in normal and 3 to 2.5 folds after 30 days and 45 days, respectively, in diabetic rats. These observations together with other evidence, suggested the significant relationship between glycosylated hemoglobin, sorbitol dehydrogenase and intake of vitamin C and vitamin B6. The elevated sorbitol dehydrogenase activity associated with the previously reported sorbitol levels. These vitamins supplementation is effective in individuals with insulin-dependent diabetes mellitus [IDDM]. They may be potentially important in controlling glucose-induced nonenzymatic glycosylation of proteins and, therefore may be a preferable drugs for inhibiting glucose induced nonenzymatic glycosylation, neural and vascular dysfunction

Cytochemical localization of sorbitol dehydrogenase in kidney and liver from Myiopsitta m. monachus (Boddaert, 1783), during embryonic development

A histochemical study to determine the localization of sorbitol dehydrogenase (SDH) in kidney and liver from embryionic, young and adult Myiopsitta m. monachus was performed. The enzyme activity increased with age in both organs. In the kidney, the enzyme appeared at the proximal convoluted tubules, and increased in the basal cytoplasm of the tubular cells. In the liver the localization was diffuse in the lobule but more intense in the cytoplasm of hepatocytes, especially in the perinuclear areas. These studies indicate that the cytochemical enzyme localization differs in this species, which is more evolutioned than Gallus gallus, and would be related to ontogenetic and phylogenetic differentiation.

Los sustitutos del azúcar en la prevención de la caries dental: revisión de la literatura / Substitution of sugar in prevention of dental caries: review of the literature

La prevención de la caries dental no sólo se limita al uso del fluoruro y/o selladores de fosetas y fisuras, que combinados con una adecuada educación para la salud e higiene bucal disminuyen la frecuencia de caries dental. La utilización parcial de ciertos sustitutos del azúcar en la dieta ha mostrado tener efectos cariostáticos. Se presenta una revisión de la literatura sobre sustitutos del azúcar, con el propósito de identificar los diferentes tipos de edulcorantes desarrollados y describir sus características, haciendo énfasis en los alcoholes del azúcar como el xilitol y sorbitol, que han mostrado poseer un efecto cariostático. Se describe su posible mecanismo de acción y se informan acerca de diferentes estudios realizados al respecto

Effect of gossypol on few testicular enzymes in mature rats.

Effect of oral administration of gossypol acetic acid (15 mg/kg/day) for 10 weeks, on certain enzymes, which may be taken as markers for the different stages of spermatogenesis, was studied in male albino rats. Gossypol produced a significant decrease in hyaluronidase and sorbitol dehydrogenase, while no change was observed in beta-glucuronidase and acid phosphatase. A significant increase in the total lactate dehydrogenase activity was observed in the testis. The possible significance of these findings is discussed.