Distal axonopathy in streptozotocin diabetes in rats

Summary We noted the earliest morphological changes in the motor endplates 8 weeks after the induction of streptozotocin diabetes in rats. Morphometric measurements showed reduced axonal areas of the lateral plantar and the sicatic nerves in the diabetic rats 28 but not 2 and 8 weeks after the experiment. These findings suggested distal axonopathy.     

Developmental change of EEG in rat from 4th to 16th week.

The development of EEG in 8 male rats from 4 to 16 weeks age were studied chronically. Theta band had the highest power at 5--16 weeks. Especially after 11 weeks, theta band presented a significantly higher peak than that of 4-week-old. In contrast to this, delta band, which had the highest power at 4 weeks, was markedly decreased.     

Developmental change of EEG in rat from 4th to 16th week

Summary The development of EEG in 8 male rats from 4 to 16 weeks age were studied chronically. Theta band had the highest power at 5–16 weeks. Especially after 11 weeks, theta band presented a signigicantly higher peak than that of 4-week-old. In contrast to this, delta band, which had the highest power at 4 weeks, was markedly decreased.     

Liver vitamin A stores in chronic alcoholism in rats: effect of propylthiouracil treatment

Administration of alcohol to rats through drinking water for 8 weeks produced a significant decrease in the liver vitamin A stores without causing any change in the plasma vitamin A levels. Treatment of the alcoholic rats with propylthiouracil for 2 weeks restored the liver vitamin A reserves to control levels.     

Liver vitamin A stores in chronic alcoholism in rats: Effect of propylthiouracil treatment

Summary Administration of alcohol to rats through drinking water for 8 weeks produced a significant decrease in the liver vitamin A stores without causing any change in the plasma vitamin A levels. Treatment of the alcoholic rats with propylthiouracil for 2 weeks restored the liver vitamin A reserves to control levels.     

链霉素诱导的2型糖尿病大鼠模型的肾脏功能变化

目的通过观察链霉素诱导的2型糖尿病大鼠模型肾脏功能的变化,以探讨此种模型是否适用于糖尿病肾损害的研究。方法采用链脲佐菌素(streptozotocin,STZ)辅以高脂饮食建立2型糖尿病大鼠模型,筛选造模成功的大鼠为糖尿病组,并与正常大鼠比较,造模后8周观察两组大鼠血糖、血尿素氮(blood urea nitrogen,BUN)、血肌酐(creatinine,CR)、血糖基化终末产物(Advanced glycation end products,AGE)、尿微量白蛋白、肾重指数的变化以及AGE受体(Receptor of AGE,RAGE)、蛋白激酶C(protein kinase C,PKC)、蛋白激酶A(protein kinase A,PKA)在肾脏的表达变化。结果糖尿病组的血糖、血尿素氮、血肌酐、血AGE、尿微量白蛋白以及肾重指数均明显高于正常组(P0.05),RAGE、PKC的mRNA以及蛋白表达水平均较正常组高(P0.05),PKA的mRNA和蛋白表达水平则较正常组低(P0.05)。结论 STZ诱导的2型糖尿病大鼠模型在造模后第8周肾脏功能存在明显的损害,并且导致肾脏损害的上游重要介质RAGE、PKC、PKA在第8周都有着明显的变化。此种模型能够用于糖尿病肾损害的研究,并且是观察中早期糖尿病肾病的较好的模型。     

Roux-en-Y胃旁路术对2型糖尿病大鼠肾脏非对称性二甲基精氨酸代谢的影响

目的研究Roux-en-Y胃旁路术对2型糖尿病大鼠肾脏非对称性二甲基精氨酸(ADMA)代谢的影响。方法 40只SD大鼠,随机分为正常对照组(NC组,n=8)和糖尿病模型组(32只)。糖尿病模型组成模30只,随机分为糖尿病对照组(DC组,n=8)、糖尿病假手术组(DSO组,n=8)及糖尿病手术组(DO,n=14),DO组行胃旁路术,DSO组行胃窦十二指肠离断原位吻合。检测术前、术后1、2、4、8周血胰高血糖素样肽(GLP-1)水平,测定术前、术后8周空腹血糖(FBG),肾脏ADMA、血尿素氮(BUN)、肌酐(Cr)、一氧化氮(NO)水平,一氧化氮合酶(NOS)活性;检测蛋白质精氨酸甲基转移酶1(PRMT1)mRNA及二甲基精氨酸二甲胺水解酶1(DDAH1)mRNA,PRMT1蛋白表达水平,PAS染色观察肾脏组织学变化。结果随着手术时间延长,D0组GLP-1水平增加,其余各组无明显变化(P0.05),术后8周,DC和DSO组较DO组和NC组FBG、BUN、Cr、ADMA水平,PRMT1mRNA和蛋白表达水平均明显升高(P0.05),NO、NOS、水平、DDAH1的mRNA表达明显降低(P0.05);PAS染色示DC组和DSO组肾小球基质沉积,阳性染色物增多,余无明显变化。结论 2型糖尿病肾脏组织中的ADMA升高;胃旁路术促进ADMA代谢,改善了肾功能。     

Latent iron deficiency alters gamma-aminobutyric acid and glutamate metabolism in rat brain

A diet containing 18-20 mg iron/kg to young weaned rats for 8 weeks altered the metabolism of gamma-aminobutyric acid and glutamate in the central nervous system without affecting blood hemoglobin. Subsequent rehabilitation with 390 mg iron/kg diet for 2 weeks normalized these changes.     

Latent iron deficiency alters gamma-aminobutyric acid and glutamate metabolism in rat brain

Summary A diet containing 18–20 mg iron/kg to young weaned rats for 8 weeks altered the metabolism of gamma-aminobutyric acid and glutamate in the central nervous system without affecting blood hemoglobin. Subsequent rehabilitation with 390 mg iron/kg diet for 2 weeks normalized these changes.     

Sequential changes in serum glucose,triglycerides and cholesterol in aging of normal and alloxan-diabetic rats

Summary 16-week-old Wistar, alloxan diabetic rats exhibited progressive elevations in levels of serum glucose, total triglycerides, cholesterol and creatinine over a period of 8 weeks; hyperglycemia preceeded hyperlipidemia and hypercreatininemia and hypertriglyceridemia preceeded hypercholesteremia. Age-matched control rats failed to develop any signs of hyperglycemia or hypercreatininemia, but did develop both hypercholesterolemia and hypertriglyceridemia at 24 weeks of age. This suggests that the progressive cardiovascular derangements (e.g., atherosclerosis, hypertension) noted in experimental diabetes mellitus and in the normal aging (and maturation) process may be brought about by distinctly different biochemical processes.Supported by NIH grant nos. HL-18002 and HL-18015 and NIDA grant No. DA-02339.     

Quantitative immunofluorescence of tyrosine hydroxylase in the adrenal medulla of spontaneously hypertensive rats

The amount of tyrosine hydroxylase protein in the adrenal medulla, which was estimated by a quantitative immunofluorescence method, was higher in spontaneously hypertensive rats than in normotensive control Wistar-Kyoto rats at 4 and 16 weeks of age before and after the development of hypertension.     

Renal denervation delays blood pressure increase in the spontaneously hypertensive rat

Summary Bilateral surgical and chemical denervation of the kidneys in spontaneously hypertensive rats, performed 5 weeks after birth, delayed blood pressure increase by 2–3 weeks without affecting the rate of development or the final level of hypertension.Acknowledgments. Dr J. Altman, INSERM, U 25, Paris, France, provided the spontaneously hypertensive rats. The technical assistance of Miss L. Viguité is gratefully acknowledged.     

Methimazole treatment reduces cardiac hypertrophy and mortality without a concomitant reduction in blood pressure in established Goldblatt two-kidney one clip hypertension

The effects of methimazole, and antithyroid drug, on blood pressure and other parameters were evaluated in the established phase of Goldblatt two-kidney one clip (G2K-1C) hypertension. Methimazole was administered via drinking water for five weeks, starting five weeks after hypertension had been induced. After this period of treatment, similarly high blood pressures were observed in methimazole-treated and non-treated G2K-1C rats, despite the fact that a hypothyroid state had been achieved in methimazole-treated rats. Methimazole-treated G2K-1C rats showed reductions in heart rate, ventricular weight, ventricular/body weight ratio and mortality in comparison with rats not treated with methimazole. These results clearly demonstrate that hypothyroidism induced by methimazole: a) does not reverse G2K-1C hypertension, but b) improves the rate of survival and c) reduces relative cardiac hypertrophy, possibly by the reduction in cardiac work observed in Goldblatt hypothyroid rats.     

Methimazole treatment reduces cardiac hypertrophy and mortality without a concomitant reduction in blood pressure in established Goldblatt two-kidney one clip hypertension.

The effects of methimazole, an antithyroid drug, on blood pressure and other parameters were evaluated in the established phase of Goldblatt two-kidney one clip (G2K-1C) hypertension. Methimazole was administered via drinking water for five weeks, starting five weeks after hypertension had been induced. After this period of treatment, similarly high blood pressures were observed in methimazole-treated and non-treated G2K-1 C rats, despite the fact that a hypothyroid state had been achieved in methimazole-treated rats. Methimazole-treated G2K-1 C rats showed reductions in heart rate, ventricular weight, ventricular/body weight ratio and mortality in comparison with rats not treated with methimazole. These results clearly demonstrate that hypothyroidism induced by methimazole: a) does not reverse G2K-1 C hypertension, but b) improves the rate of survival and c) reduces relative cardiac hypertrophy, possibly by the reduction in cardiac work observed in Goldblatt hypothyroid rats.     

Circadian rhythm of plasma corticosterone in vagotomized rats

Summary In vagotomized rats, 2 weeks after surgery, the amplitude of the circadian rhythm of plasma corticosterone was extremely low, indicating that gastrointestinal activity may be in part involved in the hypothalamo-hypophyseal circadian rhythmicity.     

Vascular reactivity in chronic Goldblatt two kidney-one clip hypertensive rats

We studied the possible contribution of increased vascular reactivity in the chronic phase of Goldblatt two kidney-one clip hypertension. Vascular reactivity was evaluated in aortic strips from hypertensive rats (16 weeks after inducing hypertension) and age-matched control rats. The findings were: a) increased sensitivity to vasopressin in the aortic tissue of hypertensive rats, b) a similar response to angiotensin II, noradrenaline and KCl in hypertensive and control rats, and c) reduced maximal response to angiotensin II compared with other vasoconstrictors in both groups of rats. These results suggest a possible role for vasopressin in the chronic phase of this model of hypertension.     

Effect of intratumoral injection of bacterial and viral neuraminidase in rats]

We studied the effect of neuraminidase injection in rat's tumor at different doses: 5,10,50,100, 500 U and we concluded that: There was no difference between the rats treated with 5,10,50 U and the controls. The y died 3 weeks after the injection. But the rats treated by 100 at 500 U of NA died quickley, in the week, of long metastases.     

The effect of guanethidine treatment of testicular blood flow and testosterone production in rats

Testicular blood flow was measured by means of Xenon-133 clearance in control rats and rats treated with guanethidine for 3 weeks. Plasma and testis testosterone concentrations were also measured, and the effect of hCG-treatment was examined. No difference in testicular blood flow between the control group and the guanethidine-treated group was found. However, in guanethidine-treated rats, plasma and testis testosterone concentrations after hCG-treatment were significantly decreased. The results may indicate that adrenergic nerves are involved in the regulation of Leydig cell function.     

The effect of guanethidine treatment of testicular blood flow and testosterone production in rats

Summary Testicular blood flow was measured bymeans of Xenon-133 clearance in control rats and rats treated with guanethidine for 3 weeks. Plasma and testis testosterone concentrations were also measured, and the effect of hCG-treatment was examined. No difference in testicular blood flow between the control group and the guanethidinetreated group was found. However, in guanethidine-treated rats, plasma and testis testosterone concentrations after hCG-treatment were significantly decreased. The results may indicate that adrenergic nerves are involved in the regulation of Leydig cell function.     

New bone induction by demineralized bone matrix in immunosuppressed rats

Subcutaneous implantation of demineralized bone matrix (DBM) initiates a sequence of developmental events which culminate in endochondral bone formation. To test the effects of T-cell deficiency on new bone formation, the morphology of DBM-induced bone was examined in rats thymectomized at three weeks of age and in thymectomized or nonthymectomized rats lethally irradiated and reconstituted with syngeneic bone marrow. At 24 days after implantation, bone induction in control rats was appropriate for their age, while thymectomized-irradiated-reconstituted rats and thymectomized rats had significantly more new bone and larger bone marrow space than the controls. In non-thymectomized, irradiated and reconstituted rats, bone induction occurred in only 25% of the animals, compared to 95% in other groups.