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W J Kort

Publications and source records attributed to W J Kort.

72 records · Page 4Linked to original sources
PubMed1982

Effect of chronic light-dark shift stress on the immune response of the rat.

During a period of 35 weeks the night-day pattern of inbred Brown Norway female rats was changed weekly by alternating the light-dark (L-D) rhythm. After a period of 2 months, in a number of the animals, the cellular immune response was measured by means of Concanavalin A stimulation of peripheral blood (Con A) and a Popliteal Lymph Node Assay (PLNA). Serum corticosterone, plasma free fatty acids and peripheral leucocytes were determined as well. Seven months thereafter the remaining animals were sacrificed after which adrenal gland weight and spleen weight were established. Additionally, blood glucose and corticosterone were measured (corticosterone in vitro activity as well as the serum level). Both Con A and PLNA showed a significantly decreased immune response in the L-D shift stress group. Adrenal cortical activity measured in vitro as well as in vivo did not show any significant changes, neither at 2 months nor at 9 months. Therefore, the observed immunosuppressive effect of chronic light-dark shift stress can not be explained by an increased adrenal cortical activity. Other possible explanations for the effect of the light-dark shift stress on the immune response are discussed.

Animals↗
PubMed1982

Intrarenal distribution of ampicillin in the healthy and the infected rat kidney: a comparison of methods.

The ampicillin concentration in the cortex of the normal and the infected rat kidney was determined by means of three different methods: tissue homogenate analysis, renal lymph analysis, and autoradiography. Both tissue homogenate analysis and autoradiography revealed that the cortical ampicillin concentration was about five times as high as the serum concentration. Renal lymph analysis disclosed that the ampicillin concentration in this fluid amounted to about 93% of the serum concentration. The discrepancy between these results can be explained on the basis of the binding of ampicillin to cellular components in the cortex. The results of the study of ampicillin distribution in infected rat kidneys with the aid of tissue homogenate analysis and autoradiography indicate that the ampicillin concentration was lower in the affected than in the intact tissue. Renal lymph analysis showed that the ampicillin concentration in the lymph was not affected by the presence of the infection. Quantitative autoradiography demonstrated that the ampicillin concentration in the cortical foci of infection was of the same order of magnitude as the serum concentration. For this kind of study autoradiography together with lymph analysis are recommended.

Ampicillin↗
PubMed1982

The glomerular filtration rate of isogeneically transplanted rat kidneys.

The glomerular filtration rate (GFR) was determined in rats with an isogeneic kidney transplant and compared with that of unilaterally nephrectomized rats. Experiments were carried out in adult rats, 3 months of age, weighing approximately 300 g, as well as in juvenile rats, 6 to 8 weeks of age, weighing approximately 170 g. All donor kidneys were taken from adult rats. The GFR was measured regularly, using a chromium 51-EDTA clearance technique which permitted repeated measurements to be taken in the same animals, during a 15-week followup period. After unilateral nephrectomy the GFR per 100 g body weight (BW) increased compared with that of a single normal kidney. Adult transplant recipients had a GFR per 100 g BW of about 80% of that of unilaterally nephrectomized rats. There was no statistical difference in the GFR when comparing adult recipients of either a normal or a hyperfunctional kidney. When isografts were transplanted to juvenile recipients, there was an initial decrease in the absolute GFR compared with the donor value in the case of a normal adult donor kidney. This decrease was even more pronounced when a hyperfunctioning kidney was transplanted to a juvenile recipient. However, when related to BW the GFR was, as in the adult recipients, about 80% of that of unilaterally nephrectomized juvenile rats. During the followup period the systolic blood pressure was measured regularly by tail plethysmography, in order to detect any blood pressure elevations, which are a frequent complication in adult and pediatric human renal transplantation. However, no hypertension was observed after isogeneic kidney transplantation in the various groups. These results show that the GFR of isogeneically transplanted rat kidneys amounts to about 80% of the maximally attainable level. Isogeneic transplantation of an adult kidney to a juvenile recipient results in a rapid adaptation of the GFR to the smaller size of the body and does not cause an increase in blood pressure.

Age Factors↗
PubMed1982

Synergism of (15 S)-15-methyl-prostaglandin E1 with either azathioprine or prednisolone on the survival of heart allografts in rats.

Survival time of Brown Norway (BN) to Wistar (WR) heart allografts without immunosuppressive treatment is 7-10 days. Azathioprine or prednisolone do not improve the graft survival in this model significantly. However, treatment with (15 S)-15-methyl-PGE1 (15-M-PGE1), a synthetic long acting prostaglandin, which can be administered orally, in combination with either azathioprine or prednisolone increased the survival of the allogeneic heart grafts substantially. A synergistic inhibitory effect of 15-M-PGE1 and prednisolone was also noted in carrageenan induced granulomatous inflammation.

Alprostadil↗
PubMed1981

Comparative study of chylomicron and fatty acid utilization in small intestine and heart.

Chylomicrons were isolated from the urine of rats after a surgical procedure in which the cysterna chyli was connected with the right ureter. The fatty acids of the chylomicrons served as a respiratory substrate for rat heart and not for rat small intestine during in vitro vascular perfusions. The reason for the absence of chylomicron utilization in small intestine was found to be the virtual absence of lipoprotein lipase from this organ. Both heart and small intestine oxidized oleate complexed to albumin. Increasing the molar ratio of fatty acid to albumin from 3 to 6 did not affect the rate of fatty acid oxidation in heart, but increased fatty acid oxidation in small intestine.

Albumins↗
PubMed1979

Effect of stress and dietary fatty acids on allograft survival in the rat.

To determine the immunosuppressive effect of stress and a diet rich on linoleic acid on vascularized organ graft survival in the rat, a series of allogeneic heart and kidney grafts were carried out. Restraint stress resulted in a significant prolongation of the survival time. Although 5 days of postoperative stress gave the best results, 3 h of stress given on the first postoperative day already gave a marked prolongation of the survival time of kidney allografts. The beneficial effect of stress on heart survival was abolished when prior adrenalectomy was carried out. A diet high on polyunsaturated fatty acids gave significant prolongation of the survival times of kidney-grafted rats. A diet hgh on saturated fatty acids did not result in a statistical significant prolongation of the survival time, although the difference with the polyunsaturated fatty acid group was very small and not statistically significant. It was concluded that stress and diets high in certain types of fatty acids depress the immune response in rats, possibly via a mechanism which has some common pathways. The adrenal glands could play an important role in this immune inhibition.

Adrenal Glands↗
PubMed1975

Vasocystostomy, a new technique of sperm output measurement.

A vasocystostomy in the rat is described, a new technique simplifying the common methods of spermatozoa output measuring. In two series of different rat strains a mean output of 21.1 X 10(6) and 29.0 X 10(6) spermatozoa per 24 h were found. Perspectives of the new method are discussed.

Animals↗
PubMedDate not supplied

Modulation of metastatic ability by inhibition of cholesterol synthesis.

Synvinolin (MK-733), a potent inhibitor of 3-hydroxy-3-methylglutaryl coenzyme-A reductase (HMG-CoA reductase) depressing de novo synthesis of cholesterol, was given to BN472 tumor cells in culture medium, 2 days prior to i.v. injection of the cells into syngeneic rats. Another group of rats received cells cultured under the same conditions but without synvinolin. Two different types of culture medium were used, a 'complete' medium (Hybridoma) and a medium (RPMI 1640) to which 1 per cent of fetal calf serum (FCS) was added. Tumor cells cultured in the presence of synvinolin showed significantly lower cholesterol values than untreated cells. Tumor cells treated with synvinolin had a decreased ability to form metastatic nodules when compared with control cells. The results supply further evidence for the suggestion that cholesterol modulates the ability of mononuclear cells to eliminate tumor cells, although it cannot be excluded that alteration of cell growth plays an important role as well.

Animals↗
PubMedDate not supplied

Inhibition of tumor metastasis by carrageenan-induced granulomas.

At -1, 0, +1 weeks from tumor inoculation, carrageenan-impregnated cotton sponges were subcutaneously implanted. Tumor BN472, a malignant adenocarcinoma, was transplanted in syngeneic Brown Norway female rats, either subcutaneously or intravenously. Plasma eicosanoid values (prostaglandin-E2, thromboxane-B2 and 6-keto-prostaglandin-F1 alpha) were determined as well as the cellular immune response (natural killer activity, concanavalin-A and phytohemagglutinin stimulation of spleen lymphocytes). Primary tumor growth and the number of tumor foci in the lungs were measured as parameters of tumor growth and dissemination. No statistically significant differences were observed in primary tumor growth. However, the number of metastatic foci in the lungs of rats in which the tumor was implanted subcutaneously, as well as those in which the tumor was inoculated intravenously, was significantly reduced in those that had carrageenan implanted one week after tumor inoculation. In all other carrageenan-treated groups only slightly reduced numbers of metastatic foci were seen. In those rats with a decreased number of tumor metastatic foci in the lungs, no correlation could be shown with either altered plasma prostaglandin levels, or cellular immune response.

6-Ketoprostaglandin F1 alpha↗