Decrease of pituitary adenylate cyclase activating polypeptide and its type I receptor mRNAs in rat testes by ethanol exposure

The present study was designed to evaluate the effect of ethanol on pituitary adenylate cyclase activating polypeptide (PACAP) and its typ I (PAC1) receptor expression in adult rat testes. Ethanol (3 g/kg i.p., 15% v/v in saline) was administrated to adult male rats for 10 days. Using northern blot analysis, the present study showed the reduction of PACAP mRNA levels in rat testes by ethanol administration. Also, ethanol decreased the expression level of PAC1 receptor in testes. In particular, in situ hybridization clearly showed the decrease of PAC1 receptor mRNA expression in Leydig cells, which produce testosterone. Furthermore, the serum level of testosterone was significantly decreased in the ethanol-treated group. In conclusion, our findings suggest that the decrease of PACAP and PAC1 receptor expression in rat testes by ethanol exposure may partly contribute to the suppression of male reproductive activity.     

The effects of growth and disease in serum keratan sulfate concentration in dogs

The purpose of this study is to investigate keratan sulfate (KS) concentration in the serum of puppies and the effects of age, body weight, breed and diseases. Serum samples from six neonatal dogs (4 Beagles, 2 Labrador Retrievers), and from 127 adult dogs with various diseases were collected at a Teaching Animal Hospital. Canine serum KS concentration was measured by inhibition enzyme-linked immunosorbent assay (ELISA). Samples from puppies were evaluated for growth-related changes, and samples from patients were evaluated for age, body weight, breed and disease-related changes. Serum KS concentration was high in puppies from birth to 4 months of age. KS values started to decrease from 4 months to 9 months of age, and then gradually reached to the plateau. Though in the small sample, mean KS concentration in a Labrador Retriever was higher than in Beagles during the first 10 months. The values of serum KS showed body weight-related increase within retrievers among teaching hospital population and there was significant increase in body weight-related change. Cartilage metabolism is high in canine immature joint and that activity continues for 5 months, and that higher in Labrador Retrievers rather than in Beagles. There was no effect from other factors, including age, body weight, breed and disease in all patients. Serum KS concentration of Retrievers is higher than Beagles, and that value increased with gain of body weight. We suggest that Retriever have higher cartilage metabolism with growth or ageing.     

Effects of Alendronate on A Disintegrin and Metalloproteinase with Thrombospondin Motifs Expression in the Developing Epiphyseal Cartilage in Rats

A disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) have been reported to play a role in the degradation of aggrecan, a major component of cartilage. This study was performed to examine the effects of alendronate on the expression of ADAMTS in developing femoral epiphyseal cartilage. Primary cultured chondrocytes from this cartilage were treated with alendronate in vitro and postnatal day 1 rats were injected subcutaneously with alendronate (1 mg/kg) every second day in vivo . The number of cultured chondrocytes and their aggrecan mRNA levels were unaffected by the alendronate treatment at 10⁻⁶ to 10⁻⁴  m concentrations. The mRNA levels of ADAMTS-1, -2 and -9 in chondrocytes were also unaffected. However, the levels of ADAMTS-5 and -4 were reduced significantly by the same treatment. The thickness of the proliferating chondrocyte layers and the aggrecan mRNA levels in the epiphysis were unaffected by the alendronate treatment in vivo . However, the hypertrophied chondrocyte layers became significantly thicker, and the size of the secondary ossification centre was reduced significantly by the same treatment ( P  < 0.05). Both ADAMTS-4 and -5 mRNA expressions were also reduced significantly in vivo . The immunoreactivity against ADAMTS-4 was seen in hypertrophied chondrocytes and reduced significantly by the alendronate treatment. These results suggested that alendronate can inhibit the degradation of aggrecan in the articular cartilage by downregulating the expression of matrix enzymes such as ADAMTS-4 and -5.     

Relationship between endogenous protein disulfide isomerase family proteins and glutenin macropolymer

The effects of endogenous protein disulfide isomerase (PDI) family proteins on the properties of gluten proteins in dough during breadmaking were determined using bacitracin, an inhibitor of PDI. Bread loaf volume in the presence of bacitracin was increased to 118% of that in the absence of bacitracin. The addition of bacitracin caused a decrease in the extension tolerance of the dough. The amount of sodium dodecyl sulfate (SDS)-insoluble glutenin macropolymer (GMP) in dough decreased to approximately 70% of that in flour during the 20 min of mixing for doughmaking. The addition of bacitracin to dough caused a dramatic GMP decrease, corresponding to ～20-30% of that in flour during the 20 min of mixing. The decrease in GMP was compensated by an increase in SDS-soluble glutenin polymer. Taken together, these results suggest that the endogenous PDI family proteins in flour suppress the depolymerization of GMP during dough mixing.     

Ligation of caeca improves nitrogen utilisation and decreases urinary uric acid excretion in chickens fed on a low protein diet plus urea

1. The effect of the ligation of the caeca on nitrogen utilisation and nitrogen excretion was examined in conventional chickens fed a diet containing 50 g protein/kg plus urea.

2. Ligation of the caeca significantly improved nitrogen balance and utilisation by up to more than 2 times as much as those of controls (P< 0.05).

3. The treatment significantly decreased uric acid excretion by 77 mg nitrogen/day (P< 0.01) and also total nitrogen excretion (P<0.05): the former decrease almost explained the latter.

4. No effect of the ligation of caeca on urea and ammonia excretion was observed.

5. It is concluded that nitrogen metabolism in chickens is affected by possible changes in caecal fermentation by preventing entry into the caeca of substances from urine and digesta.     

Acute toxicity of organochlorine insecticide endosulfan and its effect on behaviour and some hematological parameters of Asian swamp eel (Monopterus albus, Zuiew)

In Asia, Monopterus albus (Asian swamp eel) is commonly found in rice fields, muddy ponds and swamp areas. Because of its habitat, it is exposed to toxic pesticides used in rice fields, especially endosulfan, which is one of the most widely used insecticides. This study aims to determine the acute toxicity of endosulfan and its effect on the behaviour and some hematological parameters of the fish. The 96 h-LC₅₀ (with 95% confidence limits) obtained in this study for M. albus was 0.42 (0.35-0.50) μg L⁻¹. After 96 h exposure to endosulfan, the fish exhibited a series of abnormal behavioural responses; these included imbalanced position, restlessness of movement, erratic swimming, tremor, flashing and lethargy. When the swamp eels were exhausted, they were laterally recumbent on the bottom and had no opercula movement. Endosulfan toxicity also caused a significant lower (p < 0.05) value of erythrocyte count, leukocyte count, hemoglobin and hematocrit as compared to the control experiment. Nevertheless, the erythrocyte cell showed an increasing trend in size. The swollen erythrocyte cells may be impaired in their oxygen-carrying capacity. Severe blood loss through the gill capillary and hematemesis of the fish may be the main reasons for the hematological changes in the test organisms. Despite its relatively bigger size (30-40 cm in length) as compared to most of the other test organisms (<5 cm in length) for endosulfan toxicity, it is interesting to find that this fish is one of the most sensitive freshwater fishes to endosulfan.     

对于柿和君迁子角斑病(Cercospora kaki Ell.&Ev.)的研究

 柿樹虽然是亚热带果樹,但在我国分布很广,南自海南島,北迄河北省長城一带都有柿的栽培,从数量上看,有許多省如河南、河北、山东、陝西、湖北等,柿的栽培都占果樹栽培中重要地位。     

籼稻品种味度及淀粉RVA谱特性配合力分析

选用8个籼稻品种,采用Griffing双列杂交方法Ⅳ,对稻米味度及淀粉黏滞性谱（RVA谱）特性配合力进行分析。结果表明,(1) 在稻米味度、最高黏度、最低黏度、最终黏度、下降黏度值、黏滞峰消减值、回冷黏滞性恢复值等特性中,亲本基因的加性效应对杂种一代起主导作用,而糊化开始温度的遗传变异主要来自基因的非加性效应;(2)