Search PubMed⌕ Search

Biomedical subjects

P Kugler

Publications and source records attributed to P Kugler.

At least 73 records · Page 4Linked to original sources
PubMed1984

Genetic and histological aspects of stomach lesions induced by systemic injection of phenylbutazone in the rat.

Roman high-avoidance (RHA/Verh) rats, food-deprived (F-D) for 5 days, had higher stomach lesion scores than did F-D Roman low-avoidance (RLA/Verh) rats. F-D RLA/Verh rats which were injected i.p. with phenylbutazone (PBZ) 24 h before examination, however, had higher scores than did PBZ-treated, F-D RHA/Verh rats. Histologically, extensive edema and cellular infiltration (including numerous erythrocytes) were seen below the lesions, in the submucosa, denoting vascular damage. An attenuating influence of food on the ulcerogenic effects of PBZ, which were much more severe in F-D than in fed rats, was also indicated.

Animals↗
PubMed1984

Quantitative histochemistry of the angiotensinase A (APA) in the renal glomeruli of rats after stimulation of the renin-angiotensin system.

Quantitative histochemical measurements of aminopeptidase A (APA, angiotensinase A) were done kinetically in the kidney glomeruli of rats after short-term experiments (treatment with furosemide as well as captopril for 2, 4, and 6 h). The APA activities increased after treatment with furosemide or captopril. Highest activities were determined after 4 h using furosemide and 6 h using captopril. It is concluded that glomerular APA activities correspond to the renin/angiotensin plasma levels and that the fast changes of APA activities are well demonstrable by kinetic densitometric measurements in situ.

Aminopeptidases↗
PubMed1984

Comparative enzyme histochemical study on the visceral yolk sac endoderm in the rat in vivo and in vitro.

Histochemical study of the visceral yolk-sac endoderm of the rat was performed in vitro (whole-embryo culture for 24, 48 and 72 h explanted at 9.5 days of gestation) and in vivo (10.5, 11.5 and 12.5 days of gestation) in order to compare the distribution and activity of various enzymes involved in the digestion and energy metabolism in both systems. It was shown that, both in vitro and in vivo gamma-glytamyltransferase and dipeptidylpeptidase IV are demonstrable in the apical cell membranes (membrane-bound hydrolases), while acid phosphatase, dipeptidylpeptidases I, II and acid beta-galactosidase are concentrated in the supranuclear vacuoles (lysosomal hydrolases), and cytoplasmic lactate dehydrogenase and mitochondrial enzymes (succinate dehydrogenase, NAD-dependent isocitrate dehydrogenase, cytochrom oxidase) are localized in the whole cytoplasm and mainly in the apical cytoplasm, respectively, of the visceral yolk-sac epithelium. In vivo, the activity of all enzymes increased until 12.5 days, but in vitro, this activity increased only until 48 h after the start of culture (corresponding to 11.5 days in vivo). Comparison of the yolk sacs at 10.5 and 11.5 days in vivo with those after 24 and 48 h in vitro showed that the activities of all the investigated enzymes were almost identical. Yolk sacs which were cultured for 72 h showed lower activities of lysosomal and mitochondrial enzymes than those at 12.5 days in vivo. It is concluded that the digestive function and energy metabolism of the visceral yolk-sac epithelium are almost identical in vitro and in vivo at 10.5 and 11.5 days.

Animals↗
PubMed1984

[Peptidases in the kidney of male rats following castration and testosterone substitution].

The localization of aminopeptidase M (APM), dipeptidyl peptidase I (DAP I), II (DAP II) and IV (DAP IV) in the renal section was investigated histochemically, and their activities were determined fluorometrically in renal homogenate of normal, castrated and testosteron treated male rats.--After castration the activities of the lysosomal DAP II (pars convoluta of the proximal tubule), DAP I (distal and proximal tubule) and of the mainly membrane-bound DAP IV (glomeruli, brush border of the proximal tubule) increase in comparison to normal males, whereas the activities of the brush border-bound APM decrease. After testosteron treatment of castrated animals (0.1, 0.5 and 1.0 mg testosterone proprionate/100 g BW and day; 5-day treatment) the activities of DAP I, II and IV decrease again, so that after treatment with 0.1 mg testosterone proprionate, the activities of DAP I and II approach those in normal males.--The additionally determined urinary protein excretion shows that there is a significant decrease in proteinuria after castration, whereas testosterone treatment of castrated animals is accompanied by an increase of proteinuria.--Our results would suggest that the protein catabolism in the proximal tubule and the proteinuria are interrelated, and that testosterone influences (decreases) the protein catabolism in the proximal tubule. This means that high activities of lysosomal proteinases in the proximal tubule (castrates) are accompanied by a low proteinuria, and low activities of those proteinases (testosterone treated castrated or normal males) by a high proteinuria.

Aminopeptidases↗
PubMed1984

[Sex differentiated protein pattern in the urine of the rat following castration].

Protein excretion and protein fractions according to their molecular weight (SDS polyacrylamide-gelectrophoresis) were studied in the urine of male and female rats before and after castration. The polyacrylamide-gels were investigated qualitatively as well as quantitatively by densitometry. Male rats excrete considerably more protein in the urine than female rats. The values for the absolute protein quantity in 24-h-urine and the relative proteinuria (mg protein per 24 h and 100 g body weight) are five and three times higher, respectively, in males than in females. After castration proteinuria decreases significantly in both sexes, in males, however, more considerably (by about 75%) than in females (by about 30%), so that there is no significant difference in relative proteinuria between castrated males and females. The electrophoresis method used in this study allows to distinguish at least 10 to 11 protein fractions in the total urinary protein of both sexes within a molecular weight range from about 94.000 d to 14.000 d. Low molecular weight proteins (about 31.000 d to about 14.000 d) represent in both sexes the main part of the urinary protein. Females, however, excrete relatively more high molecular weight proteins (about 94.000 d to 60.000 d; about 25% of total urinary protein) than males (about 15% of total urinary protein). Concerning the relative parts in total urinary protein there are sex differences in all protein fractions, especially, however, in the fraction with a molecular weight of about 19.000 d (males more than 50%, females about 17% of total urinary protein). Castration causes in males more distinct changes in the relative parts of protein fractions in total urinary protein (drastic decrease of the 19.000-d-fraction) than in females. The results can be interpreted among other things in connection with a sex different handling of proteins in the proximal tubule of the rat kidney. The lysosomal catabolism of proteins in the proximal tubule is probably lower in males than in females, thus contributing to a higher proteinuria and a higher excretion especially of low molecular weight proteins in males in comparison with females.

Animals↗
PubMed1983

Angiotensinase A in the renomedullary interstitial cells.

Aminopeptidase A (angiotensinase A; APA) was demonstrated by histochemical means in the renomedullary interstitial cells of the golden hamster, rat, guinea pig and hare. The highest APA activities were shown in the interstitial cells of the hamster. Ultracytochemical studies of the kidney medulla of the hamster indicated that APA is localized mainly on the cell membranes of interstitial cells. Reaction product was also observed intracellularly in the nuclear membrane region. Besides the interstitial cells, APA was demonstrable ultracytochemically in the endothelial cell membranes of medullary blood vessels. Biochemical studies of APA in the renal medulla of experimental animals (sodium loaded and sodium depleted hamsters) have shown that significant changes of APA activities were available only after sodium loading, namely a decrease of APA activities in comparison to control animals. - APA through its degradation of angiotensin, is presumed, to have a bearing on the angiotensin induced prostaglandin biosynthesis of renomedullary interstitial cells.

Aminopeptidases↗
PubMed1983

Environmental and genetic effects on food-deprivation induced stomach lesions in male rats.

When Roman high- and low-avoidance (RHA/Verh and RLA/Verh) rats were individually housed in plastic cages with sawdust bedding and food-deprived (F-D) for 4-5 days, it was found that F-D RHA/Verh rats had more lesions than their unfasted controls and more lesions than F-D RLA/Verh rats. The lesions were mostly petechial in nature and located in the glandular portion of the stomach. Also, F-D RHA/Verh rats which were housed in the same room as the controls, as well as F-D RHA/Verh rats which were housed in a separate room with a strong food odor present, had more lesions than F-D RHA/Verh rats housed in the same separate room when there was no food odor, and when none of the rats present had access to food. When F-D RHA/Verh and F-D RLA/Verh rats were individually housed in metal cages with grid floors, however, a general increase in lesion scores resulted and differences between the two rat lines disappeared, as did differences among the room conditions. Also, many lesions were of an ulcerative nature and were located in the rumenal portion of the stomach. It was concluded that sensory (in this case olfactory, at least) and genetic factors are capable of playing roles in the induction of stomach lesions in rats, and that the type, extent and location of the lesions can depend upon whether or not the animals have access to sawdust bedding.

Animals↗
PubMed1983

[Topochemistry of aminopeptidase A (angiotensinase A) in the kidney cortex of the golden hamster].

The localization of aminopeptidase A (APA; E.C. 3.4.11.7) in the kidney cortex of the golden hamster was demonstrated by histochemical means (simultaneous azo coupling technique; alpha-L-Glu-MNA as substrate and HNF as coupling agent). APA was shown in the renal corpuscle (mainly podocytes and epithelium of the Bowman's capsule), the brush border of the proximal tubule, the perivascular tissue and some peritubular capillaries.--The demonstration of APA in the perivascular tissue of the juxtaglomerular apparatus (JGA) appears to have bearing on the regulation of angiotensin effects in the JGA for APA is an angiotensin degrading enzyme.

Aminopeptidases↗
PubMed1982

The intrarenal renin-angiotensin-system. An immunocytochemical study on the localization of renin, angiotensinogen, converting enzyme and the angiotensins in the kidney of mouse and rat.

The localization of renin, converting enzyme (CE) and angiotensin II (ANG II) in the kidneys of rats and mice was investigated with immunocytochemical methods. According to the presence and specific intrarenal localization of these components of the renin-angiotensin-system (RAS) our results suggest that in addition to the well known systemic effects of the RAS, there are interactions of its components inside the kidney. These interactions may lead to the generation of an extra portion of ANG II in the renal blood stream with its target cells determined by the localization of CE at the luminal side of well defined endothelial areas. These intrarenal-intravasal reactions may or may not reinforce the action of "systemic" ANG II, generated prerenally. In addition, the existence of true intrarenal-interstitial interactions, with the different components and actions of this intrarenal RAS restricted entirely to the kidney is suggested by our results, particularly the demonstration of ANG II within epitheloid cells and the dissociation of systemic renin and ANG II from their local concentrations in renal hypertensive rats.

Angiotensinogen↗
PubMed1982

Quantitative histochemistry of the lysosomal dipeptidyl aminopeptidase II in the proximal tubule of the rat kidney.

The activity of the lysosomal dipeptidyl aminopeptidase II (DAP II) was measured by quantitative histochemical methods in the S1/S2 segments of the proximal tubule using freeze dried and celloidin mounted cryostat sections (FDC sections) of rat kidney. The methodological studies show that there is a linear relationship between the amount of reaction product and reaction time for the first 5 min, as well as section thickness between 4 and 10 microns. Maximal DAP II activities were demonstrated at pH 5.5. The Km of DAP II was about 2.3 mM. In addition to the methodological studies, DAP II activity was also measured in the proximal tubule (S1/S2 segments) of experimental animals (sham-operated and castrated male and female rats). Sham-operated females showed significantly higher DAP II activities than males. DAP II activity increased significantly in castrated males so that there were no significant differences between castrated males, sham-operated and castrated females. The quantitative histochemical results are largely in agreement with biochemical data published earlier.

Animals↗
PubMed1982

Quantitative dehydrogenase histochemistry with exogenous electron carriers (PMS, MPMS, MB).

The relative efficiencies of phenazine methosulfate (PMS), 1-methoxy-phenazine methosulfate (MPMS) and Meldola Blue (MB) as electron carriers were determined biochemically (non-enzymic NADH-tetrazolium salt-test) and by quantitative histochemistry (heart and kidney slices; succinate dehydrogenase, SDH; lactate dehydrogenase, LDH). MPMS developed the highest electron transfer velocity in biochemical assays. The reaction was independent of the pH value between 7.0-8.5. PMS and MB always showed a lower transfer ability in biochemical tests which was higher with iodonitrotetrazolium chloride (INT) than with nitro blue tetrazolium chloride (NBT). A distinct pH dependence was demonstrable with MB in this respect, preferentially using INT as tetrazolium salt. Quantitative histochemical results with electron carriers are often at variance with biochemical ones. MPMS leads to somewhat higher demonstrable activities only in the determination of the NAD-dependent LDH, whereas MB results in somewhat higher LDH activity than PMS (reaction medium with agarose). MB and PMS yielded almost equally high activities in the demonstration of the flavoprotein-dependent SDH using a reaction medium with agarose. With an aqueous reaction medium, PMS resulted in higher SDH activities than MB. MPMS always had the lowest efficiency in electron transfer ability using an aqueous or agarose containing reaction medium (SDH). With PVA in the reaction medium (SDH determination) PMS was clearly superior to MPMS. MB showed only a small transfer activity under these conditions because PVA seems to bind MB almost completely. It is concluded that in histochemistry an appropriate electron carrier and electron carrier concentration must be determined for different incubation conditions, tissues, tissue preparations and dehydrogenases studied. General statements about the efficiency or inefficiency of an electron carrier as a result of only one incubation condition does not seem to be justified.

Animals↗
PubMed1982

Peptidases in the kidney and urine of rats after castration.

The localization of various peptidases in the renal section of the rat was investigated histochemically, and their activities were determined fluorometrically in renal homogenate. The membrane-bound peptidases aminopeptidase A (APA), aminopeptidase M (APM), gamma-glutamyl-transferase (gamma-GT), dipeptidylpeptidase IV (DAP IV), and the lysosomal dipeptidyl peptidases I (DAP I) and II (DAP II) were investigated in male and female (estrus) rats both before and 30 days after castration. In addition, protein excretion and APA, APM, DAP I and DAP IV activities were measured in the urine of these animals. Histochemically, the membrane-bound peptidases are demonstrable mainly in the brush borders of the proximal tubules. In addition, APA and DAP IV are found in the glomeruli, gamma-GT and DAP IV in the thin descending limbs of the loops of Henle, and gamma-GT in the basal labyrinth of the S2 and S3 segments. The lysosomal peptidases are most concentrated in the S1 and S2 segments of the proximal tubule, in the distal tubule, and in certain cells of the connecting tubule and collecting duct, where they are contained in lysosomes of varying size. Sex differences and castration effects are demonstrable both histochemically and biochemically for the investigated peptidases. Histochemically these effects are most pronounced in the S3 segments for the membrane-bound peptidases, and in the lysosomes of the proximal tubule for the lysosomal peptidases. Biochemical tests in controls show significantly higher lysosomal peptidase activities in the renal homogenate of females than of males. After castration the lysosomal peptidase activities in males increase, approaching those of females. This appears to have bearing on the sex-dependent proteinuria in rats, for lysosomal peptidases and proteinases are particularly important in the degradation of filtered proteins that are reabsorbed in the proximal tubule. In females high lysosomal peptidase activities correlate with a low proteinuria, while males demonstrate lower lysosomal peptidase activities and a significantly higher proteinuria than females. After castration, the lysosomal peptidase activities and proteinuria in males approach those in females. Renal peptidases are also excreted in the urine, again with sex differences, and so these excreted peptidases contribute to the proteinuria in rats.

Animals↗