bluuebunny/crossref_metadata_2025_split huggingface dataset:
CHANGES IN VARIOUS TISSUES IN THE ARTERIAL WALL OF SPONTANEOUSLY HYPERTENSIVE RATS
Authors: Saito Noboru , Okada Teruhiko , Shirota Masatoshi , Yagyu Kenichi , Takatsuji Hiroyoshi , Nishiyama Shoji , Enzan Hideo 
Published: June 2007

Summary1. Using stroke‐prone spontaneously hypertensive rats (SHRSP), stroke‐resistant spontaneously hypertensive rats (SHRSR) and Wistar‐Kyoto rats (WKY), vascular complications and the longevity of rats were investigated.2. SHRSP aged more than 9.5 months tended to suffer from severe vascular complications such as periarteritis nodosa (PN) of mesenteric artery, while SHRSR very rarely showed severe vascular complications and WKY did not show any complications, because of the different level of systolic blood pressure.3. Among some tissues PN tended to occur early in the small arteries of the testes and then in mesenteric artery, when these tissues of SHRSP were investigated microscopically.4. Concerning the influence of systolic blood pressure on arterial smooth muscle layer, the deviation force of this layer was larger in SHRSR compared to WKY (44.7 times in Y axis), which was calculated mathematically and physically using computer analysis.5. The arterial wall area of PN was enlarged, resulting in the low ratio of lumen/wall. The ratio of arterial lumen/wall was lower in SHRSP when compared to the age‐matched WKY.6. In search for myocardial ischaemia, ECG was recorded. There were positive correlations between PQ interval or SV1+ R V5 and age in the three strains of rats. ST depression more than 1 mm on ECG was most prevalent in old SHRSP, indicating probably the presence of myocardial ischaemia.
CHARACTERIZATION OF RETINAL VASCULAR ABNORMALITIES IN LEAN AND OBESE SPONTANEOUSLY HYPERTENSIVE RATS
Authors: Huang Suber S. , Khosrof Samer A. , Koletsky Richard J. , Benetz Beth Ann , Ernsberger Paul 
Published: June 2007

Summary1. The obese SHR (Koletsky rat; SHR‐k) is a unique animal model for the study of microvascular changes associated with genetic obesity, spontaneous hypertension, endogenous hyper‐lipidaemia, and hyperinsulinaernic, non‐insulin dependent diabetes mellitus (Type II).2. Lean and obese SHR‐k exhibit retinal vascular changes which have not been previously characterized and are more severe than previously described in other animal models of experimental hypertension or non‐insulin dependent diabetes.3. Progressive retinal capillary dropout, capillary cell changes, vascular tortuosity and dilatation are severe. Vessels form elevated varicose vascular tortuosities which leak fluo‐rescein dye and which are more frequent in the obese SHR‐k. This study suggests that lean and obese SHR may be unique models for the study of multivariate factors in the pathogenesis of ischaemic neovascular proliferation.
INFLUENCE OF HYPERTENSIVE VASCULAR CHANGES IN INTRATESTICULAR ARTERIES ON SPERMATOGENESIS IN SHRSP
Authors: Itoh Naoki , Akagashi Keigo , Kumamoto Yoshiaki , Suzuki Tsuneyuki , Ohta Yoshio 
Published: June 2007

Summary1. The process of the spermatogenetic damage induced by hypertensive vascular changes was studied with stroke‐prone spontaneously hypertensive rats (SHRSP).2. In SHRSP, hypertensive changes in intratesticular arterioles developed from 19 weeks of age.3. At 23 weeks of age, a severe reduction in the number of mature and immature spermatids was observed.4. The transferrin concentration in testicular cytosol was decreased at 23 weeks of age, suggesting that Sertoli cell function in SHRSP had regressed.5. In conclusion, it was suggested that the decline in Sertoli cell function as a result of hypertensive vascular changes is part of the mechanism whereby spermatogenic damage occurs in SHRSP.
BIOCHEMICAL CHARACTERIZATION OF THE FIBRES OF COLLAGEN AND ELASTIN IN THE AORTIC WALL OF SHRSP
Authors: Matsumura Sueo , Kawazoye Seiji , Tian Sheng‐Fang , Takashima Toshinobu , Sunaga Toshiaki , Toda Shuji , Fujitani Noboru , Higashino Hideaki , Suzuki Aritomo 
Published: June 2007

Summary1. Vessel wall fragments consisting of collagen, elastin and other insoluble proteins were prepared from the aortas of 6 month old WKY and SHRSP and dead, elderly humans.2. Prolonged incubations of these fragments with pepsin below or at 30°C resulted in different amounts of insoluble materials containing similar or larger proportions of collagen and other insoluble proteins than the respective vessel fragments. The amounts of the pepsin‐insoluble materials obtained from SHRSP were larger than those from WKY but were much smaller than those from elderly humans.3. The elastins isolated from the vessel fragments were solubilized by pepsin much more effectively than the respective vessel fragments.4. The pepsin‐insoluble materials from WKY were composed of thin mesh‐shaped materials, while those from SHRSP were composed of denser sheet‐shaped materials. While these materials from both rats did not contain a significant number of distinctive fibrils of collagen, the materials from elderly humans did contain numerous distinctive fibrils of collagen.5. Large fractions of both the collagen and other proteins in the pepsin‐insoluble materials were solubilized by incubation with a crude bacterial collagenase below 30°C or by incubation with pepsin above 40°C where the triple‐helical regions of the collagens were unfolded.6. These results appear to indicate that the aortic wall of SHRSP contains larger amounts of some insoluble components that immobilize the collagen fibrils than that of WKY, but the aortic walls of elderly humans contain much larger amounts of these components than that of SHRSP.
BLOOD PRESSURE‐RELATED CHANGES OF ENDOTHELIUM‐DEPENDENT RELAXATION IN THE AORTA FROM SHRSP AT DEVELOPMENTAL AGES OF HYPERTENSION
Authors: Tomita T. , Onda T. , Mashiko S. , Hamano M. , Tomita I. 
Published: June 2007

Summary1. Shear stress and flow influence endothelial functions to stimulate the release of endothelium‐derived relaxing factor (EDRF). However, it is not well defined how hypertension affects endothelial functions. In this study, blood pressure‐related changes of endothelium‐dependent relaxation (EDR) in the aorta were examined in SHRSP, WKY and FI hybrid at developmental ages of hypertension, and hypotensively‐treated SHRSP.2. Acetylcholine‐induced EDR of aortic rings was significantly enhanced in 8 week old SHRSP compared with that of age‐matched WKY.3. NG‐monomethyl L‐arginine (L‐NMMA) (1 mmol/L), an inhibitor of nitric oxide, greatly reduced the relaxation in both strains. Indomethacin (10‐5 mol/L), a cyclo‐oxygenase inhibitor, did not affect the relaxation at this age.4. EDR was positively correlated (r = 0.81, n= 22) with blood pressure at 9 weeks of age in WKY, SHRSP and F1 hybrid.5. A five week hypotensive treatment of SHRSP caused a significant reduction in EDR with decreasing blood pressure.6. It was concluded that the endothelium releases more EDRF in response to increasing blood pressure to regulate vascular tone at developmental ages of hypertension.
COMPARATIVE STUDY ON FREE RADICAL INJURY IN THE ENDOTHELIUM OF SHR AND WKY AORTA
Authors: Ito H. , Torii M. , Suzuki T. 
Published: June 2007

Summary1. Using 13 week old SHR and WKY rats, aortic endothelial injury was examined after tert‐butylhydroperoxide (t‐BOOH) perfusion.2. ESR analysis revealed a hydroxyl radical adducts in the perfusate after t‐BOOH perfusion.3. After t‐BOOH perfusion, endothelial changes such as cauliflower‐like blebs and crater‐like holes were frequently observed in the SHR aorta, but rarely seen in the WKY aorta.4. X‐ray spectra revealed the cerium perhydroxide deposition on the surface of endothelial cells of the SHR aorta.5. These findings indicate that free radical injury is much more intense in the endothelial cells of SHR than in those in WKY.
INFLAMMATORY CYTOKINES AND RAT VASCULAR TONE
Authors: Ohkawa Fujio , Ikeda Uichi , Kanbe Toshiko , Kawasaki Kenichi , Shimada Kazuyuki 
Published: June 2007

Summary1. Experiments were performed to examine the effect of inflammatory cytokines, interleukin‐2 (IL‐2), IL‐6 and IL‐8, on the contractility of rat aorta.2. Pretreatment of the endothelium‐denuded aortic ring with IL‐6 for 3h caused a significant inhibition of its contraction (58.9 ± 7.8%, n= 9, P < 0.01) when induced by 10−6mol/L phenylephrine.3. On the other hand, IL‐2 and IL‐8 failed to show significant effects on the contractility of the aorta.4. This inhibitory effect of IL‐6 on phenylephrine‐induced contraction showed dose‐dependency, and completely disappeared in the presence of 10−5mol/L indomethacin.5. In cultured rat vascular smooth muscle cells (VSMC), the release of 6‐keto‐prostaglandin F1α into the extracellular medium was significantly increased by exposure to IL‐6, but not by exposure to IL‐2 or IL‐8.6. IL‐2, IL‐6 and IL‐8 showed no effects on the release of nitrite, a stable metabolite of nitric oxide (NO), from VSMC.7. These results indicate that IL‐6, not IL‐2 or IL‐8, is a potent inhibitor of the α‐adrenergic‐stimulated contraction of vascular smooth muscle and its action is mediated by the increased synthesis of prostacyclin rather than NO.
MAPPING OF ANGIOTENSIN II RECEPTOR SUBTYPES IN PERIPHERAL TISSUES OF SPONTANEOUSLY HYPERTENSIVE RATS BY IN VITRO AUTORADIOGRAPHY
Authors: Song Keifu , Kurobe Yoshiko , Kanehara Hironori , Wada Takeo , Inada Yoshiyuki , Nishikawa Kohei , Miyazaki Mizuo 
Published: June 2007

Summary1. The regulation of angiotensin II (AII) receptor subtypes was studied in peripheral tissues of 20 week old male spontaneously hypertensive rats (SHR) and age‐matched normotensive Wistar‐Kyoto (WKY) rats.2. AII receptor binding was determined by a quantitative in vitro autoradiography using [125I]‐[Sar1, Ile8]AII as a ligand on the kidney, adrenal gland, thoracic aorta and heart. CV‐11974, a specific AT1 receptor antagonist, and CGP42112B, a specific AT2 antagonist, were used in competition with [125I]‐[Sar1, Ile8]AII to differentiate AT1 and AT2 receptor binding.3. The relative abundance of each subtype was very similar between SHR and WKY rats. In both strains of rats, the adrenal cortex contained predominantly AT1 receptors, while AT2 receptors predominated in the adrenal medulla. The kidney contained exclusively AT1 receptors over glomeruli, proximal tubules and outer medulla. AT1 receptors were predominant in the thoracic aorta and heart.4. As for relative receptor density, important differences were observed between SHR and WKY rats. In SHR, the adrenal cortex, outer medulla of the kidney, and heart displayed higher AT1 receptor density than WKY rats.5. These results indicate that the expression of AT1 receptors is differently regulated in some important targets of AII in SHR, and suggest that the altered regulation of AT1 receptor presented in this study should be relevant to the patho‐physiological features of SHR.
ELEVATED GLUCOSE CONCENTRATION AND NATRIURETIC PEPTIDES RECEPTOR RESPONSE ON VASCULAR SMOOTH MUSCLE OF SPONTANEOUSLY HYPERTENSIVE RATS
Authors: Yasunari Kenichi , Kohno Masakazu , Kano Hiroaki , Hanehira Takao , Minami Mieko , Ikeda Miwako , Horio Takeshi , Yokokawa Koji , Takeda Tadanao 
Published: June 2007

Summary1. Hyperglycaemia is believed to be a major cause of diabetic vascular complications such as accelerated atherosclerosis. In order to elucidate the effect of hyperglycaemia on vascular response in spontaneously hypertensive rats (SHR), the natriuretic peptides receptor responses to vascular smooth muscle cells (VSMC) which are thought to suppress atherosclerosis were studied under high glucose (HG:22.2 mmol/L) conditions.2. The total number of cells in SHR is higher and natriuretic peptides receptor response is smaller than that of cells in the Wistar‐Kyoto (WKY) rat. Membrane bound protein kinase C (PKC) activity in HG or SHR is higher compared to that of cells in normal glucose (NG:5.6 mmol/L) or WKY. Cells cultured in HG for at least 2 passages had higher total cell number and receptor mediated cGMP formation were suppressed compared to cells cultured in NG both in SHR and WKY. Specific PKC inhibitor PKC (19–36) 1 μmol/L prevented HG induced suppression of natriuretic peptides response.3. These results show that hyperglycaemia may be linked to suppressed natriuretic peptides receptor response which is caused by increased PKC activity both in WKY and SHR. This suppressed response may cause the accelerated atherosclerosis by hyperglycaemia.
GENE REGULATION OF BRAIN NATRIURETIC PEPTIDE IN CARDIOCYTE HYPERTROPHY BY α1‐ADRENERGIC STIMULATION
Authors: Nakagawa O. , Itoh H. , Harada M. , Komatsu Y. , Yoshimasa T. , Nakao K. 
Published: June 2007

Summary1. We previously demonstrated that brain natriuretic peptide (BNP) is a cardiac hormone mainly produced in the ventricle, while the major production site of atrial natriuretic peptide (ANP) is the atrium. The production and secretion of BNP and ANP in the hypertrophied ventricles were markedly augmented, serving as a compensation mechanism against ventricular overload by their natriuretic, diuretic and vasodilatory actions.2. In the present study, we prepared an in vitro model of cardiocyte hypertrophy using cultured neonatal rat ventricular cardiocytes and αl‐adrenergic stimulation, and examined the gene expressions of BNP and ANP during the process of cardiocyte hypertrophy.3. The treatment of cultured ventricular cardiocytes with phenylephrine evoked cardiocyte hypertrophy around 24 h after the treatment, which was characterized by augmented expression of the myosin light chain‐2 gene and increase in cell size.4. In this model of cardiocyte hypertrophy, the steady‐state level of BNP mRNA rapidly increased to the maximal level within 1 h after the treatment. In contrast, ANP mRNA began to increase at 3h, and accumulated during the course of cardiocyte hypertrophy. The secretion of BNP from ventricular cardiocytes was also stimulated more rapidly than the ANP secretion.5. These results indicate that the gene expression of BNP is distinctly regulated from that of ANP in cardiocyte hypertrophy, and suggest a discrete pathophysiological role of BNP as an ‘emergency’ cardiac hormone against ventricular overload.
AUGMENTED EXPRESSION OF THE ENDOTHELIN‐A RECEPTOR GENE IN CULTURED MESANGIAL CELLS FROM STROKE‐PRONE SPONTANEOUSLY HYPERTENSIVE RATS
Authors: Hiraoka Junko , Arai Hiroshi , Yoshimasa Takaaki , Takaya Kazuhiko , Miyamoto Yoshihiro , Yamashita Jun , Suga Shin‐ichi , Ogawa Yoshihiro , Shirakami Gotaro , Itoh Hiroshi , Yamori Yukio , Nakao Kazuwa 
Published: June 2007

Summary1. To elucidate the role of endothelin (ET) receptor in hypertension, we studied the expression of the ET‐A receptor (ET‐ AR) gene and the ET‐B receptor (ET‐BR) gene in cultured mesangial cells isolated from stroke‐prone spontaneously hypertensive rats (SHRSP) and Wistar‐Kyoto (WKY) rats.2. The mesangial cells from both SHRSP and WKY expressed ET‐AR predominantly. The level of the ET‐AR mRNA in mesangial cells from SHRSP was 5‐fold higher than that in the cells from WKY. The ET‐BR mRNA in the mesangial cells from both strains was hardly detectable by northern blot analysis.3. These results demonstrate that the expression of the ET‐AR gene was markedly augmented in mesangial cells from SHRSP.
ENHANCED PHOSPHOINOSITIDE TURNOVER SIGNALLING STIMULATED BY ENDOTHELIN B‐TYPE RECEPTOR IN ENDOTHELIAL CELLS FROM SPONTANEOUSLY HYPERTENSIVE RATS
Authors: Yokokawa K. , Kohno M. , Minami M. , Ikeda M. , Horio T. , Kano H. , Hanehira T. , Yasunari K. , Takeda T. 
Published: June 2007

Summary1. Endothelin (ET) B‐type (ETB) receptor‐mediated signal transduction was examined after stimulation with ET‐3 in cultured aortic endothelial cells (EC) from spontaneously hypertensive (SHR) and Wistar‐Kyoto (WKY) rats (8 weeks old).2. The EC from both rat strains expressed only ETB receptor mRNA. The receptor densities and affinities, which were non‐selective for ET‐1, ‐2, ‐3 and Sarafotoxin S6c, and mRNA expression were similar in WKY and SHR.3. The cytosolic Ca2+ level in the absence of extracellular Ca2+, inositol 1,4,5‐trisphosphate levels, protein kinase C and phospholipase C activities in response to ET‐3 were greater in SHR EC than in WKY EC.4. The 45Ca uptake in response to ET‐3, which was blocked by Ni2+, was smaller in SHR EC than in WKY EC.5. The 6‐keto‐PGF1α production was augmented in SHR, though nitric oxide formation after stimulation with ET‐3 was similar.6. These results suggest that ETB receptor‐mediated phosphoinositide turnover signalling is augmented in SHR EC through postreceptor mechanism.
EFFECT OF THROMBIN AND PDGF ON ENDOTHELIN PRODUCTION IN CULTURED MESANGIAL CELLS DERIVED FROM SPONTANEOUSLY HYPERTENSIVE RATS
Authors: Ikeda Miwako , Kohno Masakazu , Horio Takeshi , Yasunari Kenichi , Yokokawa Koji , Kano Hiroaki , Minami Mieko , Hanehira Takao , Fukui Toshiki , Takeda Tadanao 
Published: June 2007

Summary1. Basal endothelin‐1 (ET‐1) production in mesangial cells of spontaneously hypertensive rats (SHR) was not different from that of Wistar‐Kyoto (WKY) rats, although a trend toward increased ET‐1 production was observed in these cells of SHR.2. Thrombin and platelet‐derived growth factor (PDGF) stimulated ET‐1 production in a concentration‐dependent manner in these cells of both rat strains, but thrombin‐ and PDGF‐induced stimulation of ET‐1 production were clearly greater in cells of SHR than WKY rats.3. The protein kinase C (PKC)‐activating phorbol ester, phorbol myristate acetate, stimulated ET‐1 production in cells of both rat strains, but this stimulation was significantly greater in cells of SHR than in cells of WKY rats.4. An inactive enantiomer of phorbol ester, 4a‐PDD, had no effect on the ET‐1 production in these cells of both rat strains.5. Neither thrombin nor PDGF stimulated ET‐1 production in PKC‐depleted cells of both rat strains.
COMPARATIVE HAEMODYNAMIC STUDIES OF ENDOTHELIN‐1, ‐2 AND ‐3 ON CONSCIOUS SHRSP AND WKY
Authors: Higashino H. , Simeonova K. , Lambev I. , Suzuki A. 
Published: June 2007

Summary1. Depressor and pressor effects of endothelin‐1, ‐2 and ‐3 in relation to hypertension were investigated in conscious WKY and SHRSP.2. Changes of systolic arterial pressure to both depressor and pressor responses caused by three doses of endothelin‐1, ‐2 or ‐3 (0.1, 0.3 and 1 nmol/kg) occurred to a similar extent between WKY and SHRSP. These data showed that endothelins may not exert an important role on the pathogenesis of hypertension.3. Endothelin‐1 decreased the cardiac index more in SHRSP than in WKY, indicating the dominance of ETA receptors in SHRSP compared with WKY.4. ET‐1 was the most potent vasodepressor and vasodilator of three endothelin peptides in rats.5. During the pressor responses to endothelin‐1 and ‐3, cardiac arrhythmia was observed with high frequency in the animals of both groups, indicating the arrhythmogenic effect of ET.
A NEW LOCUS ON CHROMOSOME 3 STRONGLY LINKED WITH SALT‐SENSITIVE HIGH BLOOD PRESSURE IN FEMALE F2 FROM SHRSP AND WKY RATS
Authors: Matsumoto Ciho , Nara Yasuo , Ikeda Katsumi , Nabika Toru , Sawamura Makoto , Yamori Yukio 
Published: June 2007

Summary1. We investigated candidate loci for salt‐sensitive high blood pressure in F2 progeny from crossing Wistar‐Kyoto rats and stroke‐prone spontaneously hypertensive rats.2. The average systolic and diastolic blood pressure did not increase in male and female F2 progeny by the 12th day after salt loading.3. In female F2 progeny, systolic and diastolic blood pressure became strongly linked with the MITR244 locus on chromosome 3,1 month and 12 days after salt loading.4. This locus became linked with blood pressure only in the female F2 progeny and not in the males.5. These results indicate that hormonal factors and gender differences, in particular, might influence salt sensitivity.
EFFECTS OF A HIGH‐SALT DIET ON TISSUE NORADRENALINE CONCENTRATIONS IN DAHL SALT‐RESISTANT AND ‐SENSITIVE RATS
Authors: Chen Q. H. , Morita H. , Nishida Y. , Hosomi H. 
Published: June 2007

Summary1. We measured systolic arterial pressure (SAP) and tissue noradrenaline concentrations (tNA) of 16 organs (heart, kidney, aorta, brain stem, pancreas, spleen, stomach, jejunum, ileum, colon, lung, muscle, cerebrum, liver, bone, salivary gland) in Dahl salt‐resistant (DSR) and ‐sensitive rats (DSS) fed 0.4 (0.4%) or 8% salt diet (8%) from 5 weeks old until the age of 5, 7, 9 and 11 weeks.2. SAP increased in DSS with the 8% salt diet. An increased rate of SAP of DSS with the 0.4% salt diet was larger than DSR with the 0.4% diet. In DSR with 0.4%, tNA tended to increase from 5 weeks old except in the bone, which may have been the result of ageing. In DSS with 0.4%, tNA did not increase from 5 weeks old. DSS showed salt‐sensitivity even to 0.4%.3. tNA of the heart and kidney of both DSS and DSR with 8% were lower than 0.4%. These organs are high‐salt‐sensitive organs. tNA of the aorta, spleen, stomach, jejunum, ileum, and colon of DSS with 8% were lower than 0.4%, but not DSR. These organs are medium salt‐sensitive organs. tNA of the pancreas of DSS with 8% was lower than 0.4% which was not different from DSR with 0.4 and 8%. The pancreas is a low salt‐sensitive organ. tNA of the lung, muscle, cerebrum, liver, bone and salivary gland did not show any differences between 0.4 and 8% in DSS as well as DSR. These organs are not salt‐sensitive organs.4. There were large organ differences in tNA among organs studied. There were large organ differences in decrease rate of tNA in response to a high‐salt diet. The organ function and the period of salt diet influence tNA.
MAGNESIUM, CALCIUM AND TRACE ELEMENTS IN SPONTANEOUSLY HYPERTENSIVE RATS
Authors: Saito Noboru , Abbu G. C. , Konishi Yuuko , Nishiyama Shoji , Okada Teruhiko 
Published: June 2007

Summary1. Using three strains, which showed severe hypertension, mild hypertension and normotension, respectively, the relationships between electrolytes or trace elements and vascular complications combined with the factor of ageing were investigated.2. In ash materials of some tissues old female SHRSP and old WKY showed a decrease of selenium in many tissues when compared to adult female SHRSP and WKY, respectively.3. In cellular supernatant fraction, SHRSP showed a decrease of magnesium in many tissues and an elevation of the calcium to magnesium ratio when compared to age‐matched WKY and SHRSR.4. In diabetic rats induced by streptozotocin, myocardial magnesium decreased, resulting in an elevation of the myocardial calcium to magnesium ratio.5. Alpha tocopherol concentration was lower in both the myocardium and cerebrum of old female SHRSR when compared to that of adult female SHRSR.6. From these findings the elevation of calcium to magnesium ratio was found in old rats and SHRSP, indicating the tendency of tissue deterioration in these rats.7. Tissue selenium also decreased in old rats and SHRSP and this decrement was probably related to the peroxidation in tissue damage.
PECULIARITIES OF THE CELLULAR ION‐TRANSPORT FUNCTION OF THE GASTROINTESTINAL TRACT IN HYPERTENSIVE RATS
Authors: Smirnov Y. , Oslopov V. , Sorokina N. , Maklakov A. , Stolpner E. 
Published: June 2007

Summary1. A study of gastric and intestinal mucosa samples of 15 SHR and 15 normotensive rats of the line WKY was performed by proton‐pulsed NMR with a pulsed magnetic field gradient.2. The diffusion decay shape under the effect of the magnetic field gradient for intestinal mucosa cells in SHR and WKY appeared to be similar and differed drastically for gastric mucosa cells. The signal population of slow protons in SHR was lower and, with regard to fast protons, was higher than that in WKY.3. The amount of slow protons is connected with low molecular cytoskeleton proteins. The decrease of their amount in hypertensive rats can be used as a test for cell membrane defects and explains, to some extent, the increase of membrane permeability for ions in the case of essential hypertension. This phenomenon is observed only in an acid medium (with increased proton concentration).