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Biomedical subjects

V Moritz

Publications and source records attributed to V Moritz.

At least 55 records · Page 3Linked to original sources
PubMed1980

High postheparin lipolytic activity as a possible cause of hypotriglyceridemia in spontaneously hypertensive rats.

In male spontaneously hypertensive rats (SHR) and normotensive Wistar rats at 4, 8 and 20 weeks of age the postheparin lipolytic activity (PHLA) has been estimated. PHLA was significantly higher in all SHR than in age- and weight-matched controls, although it decreased with advancing age in both groups. The data are discussed with regard to hyperinsulinemia and hypotriglyceridemia in SHR ascertained by a previous study. It is assumed that in young SHR catecholamine-induced lipolysis provokes impaired glucose tolerance and higher insulin response after glucose load. Insulin enhancement can stimulate PHLA via increased synthesis of lipoprotein lipase. The resulting augmented uptake of triglycerides by adipose tissue is suggested to be a beneficial (adaptive?) mechanism to compensate a primary increase of lipolysis. The well-known lower adipose cell size and body weight in SHR in comparison to age-related normotensive control rats might indicate that this mechanism is insufficient to balance the triglyceride supply in these animals.

Animals↗
PubMed1980

Effects of a substance P-analogue on blood pressure and avoidance learning of rats with spontaneous hypertension.

A shortened and modified eledoisin-hexapeptide sequence (Lys-Phe-Ile-Gly-Leu-MetNH2) was tested for their action on avoidance learning and blood pressure of rats with spontaneous hypertension (SH-rats) and intact Wistar rats. Both groups were 10, 14, and 26 weeks of age. Disorders of avoidance learning and elevation of blood pressure were likely to aggravate along with growing age of SH-rat. The used eledoisin-hexapeptide sequence is related to the essential C-terminal pentapeptide sequence of Substance P (SP). After injection of the used hexapeptide at doses of 250 microgram/kg intraperitoneally disorders in avoidance learning were completely eliminated from ten-week SH-rats or conditionally for SH-rats aged 14 and 26 weeks. Elevated blood pressure in SH-rats aged 26 weeks was reduced by the hexapeptide from 220 Torr to approximately 190 Torr. Blood pressure in SH-rats aged 14 weeks, originally about 180 Torr, was almost unaffected by the hexapeptide. Blood pressure went up from about 150 Torr to 190 in ten-week-old Sh-rats. A hypothesis was made about the mode of action of Substance P and related peptides.

Animals↗
PubMed1979

The fatty acid pattern of triglycerides and FFA in serum of spontaneously hypertensive rats (SHR).

The fatty acid patterns of serum triglycerides and FFA in SHR and in normotensive controls aged 4, 8 and 26 weeks were estimated by gas-liquid chromatography. In serum triglycerides of SHR, the percentage of linoleic acid (C18:2) was lower and the content of arachidonic acid (C20:4) higher than in age-matched control animals. A continuous increase in palmitic (C16) and linoleic acids as well as a decrease in arachidonic acid has been found with advancing age, the most striking differences existing between 4- and 8-week-old animals, i.e. before onset of arterial hypertension in SHR. In the pre-hypertensive stage, the percentage of arachidonic acid was about 3 times as high as in later stages in SHR. This gradation was, however, even more pronounced in normotensive control rats. The C18:2/C20:4-ratio of triglycerides was lower in SHR but increased with age in both groups reaching a 5--8-fold level. Similar behavior of the FFA fatty acid pattern was less marked. Alterations in levels of linoleic and arachidonic acids are of interest because of their pathogenic role as precursors of prostaglandins in the development of genetically spontaneous hypertension in rats. The results are discussed in connection with the hypotensive effect of a linoleic acid-rich diet recently reported in hypertensive rats.

Age Factors↗
PubMed1979

Adipose cell size in spontaneously hypertensive rats (SHR).

The size of adipose cells in spontaneously hypertensive rats (SHR) and normotensive controls has been evaluated at 4, 8 and 26 weeks of age. Age-matched groups showed significant differences only in 8-week-old rats, but this can be explained by the lower body weight of SHR. In both groups of animals fat cell size varies with body weight (r = 0.965 in SHR and r = 0.863 in normotensive rats) independent of the stage of hypertension. The regression lines are not significantly different. Thus, no evidence of enlarged adipocytes in SHR has been obtained.

Adipose Tissue↗
PubMed1978

[Learning and memory processes during postnatal ontogenesis in rats with spontaneous hypertension].

The examination of learning and memory processes by a conditional reflectory locomotor avoidance reaction on 8-, 10-, 12-, 14-, 16-, 20-, 26-, and 50-week-old rats with spontaneous hypertension (SHR Okamoto/Aoki) revealed, up to an age of 20 weeks, correlations between the height of blood pressure and learning and memory performance by analogy with parameters of the hydrocarbon metabolism [1,2]. Three stages were observed: Stage I: Juvenile animals (8--10 weeks) with mean systolic blood pressure values of 150 to 170 torr showed a comparatively low restriction of learning and memory processes. Stage II: In adult animals (12--20 weeks) with mean systolic blood pressure values of 180 to 210 torr learning was inhibited by about 50%, while retention of memory was completely disturbed. Stage III: In old animals (26--50 weeks) with mean systolic blood pressure values above 200 torr the faculty to learn a conditional avoidance reflex was virtually lost. Destruction or blockage of hypothalamic behavioral substances are assumed to cause the derangement of learning and memory processes in spontaneously hypertensive rats.

Aging↗
PubMed1976

[Glucose tolerance of postnatally stress-sensitized albino rats following chronic emotional stress in adulthood].

Male albino rats were used to study the effect of electrical stimulation in the postnatal phase (day 1--15) leading to short-time convulsions and cyanosis lasting about 10 min in 5-month-old animals upon the development of glycemic dysregulation induced by emotional stress. The studies involving i.p. glucose administration show that a 3-week stress influence on postnatally stimulated animals caused heavier changes of glycemic regulation than with non-pretreated animals. These results suggest a stress sensitization occurring in the postnatal phase and are discussed in connection with the "stress-sensitive risk personality" by R. BAUMANN. Further studies have shown that the postnatal stress sensitiveness is reversible and cannot only be compensated by a rest period of several weeks but may even cause stress resistance on renewed stressing for three weeks.

Animals↗
PubMed1976

[The significance of stress intensity for the emotional and visceral reactivity, especially for blood pressure regulation].

The influence of light, medium, and heavy chronic stress upon cerebro-visceral functions following 3 and 5 weeks of daily stress exposure was examined. The following results were obtained: Light stress produced no changes of cerebro-visceral functions. Medium stress restricted the learning and memory capacity, increased systolic blood pressure, fasting blood sugar and adrenal weights. The B-cells of the pancreatic islets showed degranulations of varying intensity. Heavy stress diminished the learning and memory capacity, increased adrenal weights and led to hypergranulation of the pancreatic B-cells. Blood sugar and blood pressure values fall within physiological limits. Load tests, however, revealed in these animals symptoms of premorbid states. Since throughout the period of observation, light stress stablized the regulation processes, medium stress induced early stages of pathological processes, and heavy stress caused premorbid states, no linearity could be established between the load intensity and the changes of cerebro-visceral functions.

Adrenal Glands↗
PubMed1976

[Correlations between hippocampus function and stressed learning and their effect on cerebro-visceral regulation processes].

43 male albino rats were investigated to find out what are the effects of bilateral exclusion of pes hippocampus structures upon the development of arterial hypertension released by learning stress exposure. The following results were obtained: 5 weeks of stress exposure (learning load and heavy learning load) caused disturbances of information-processing events of the central nervous system in all the animals with hippocampal lesions. Systolic blood pressure values, fasting blood sugar values, and adrenal weights fall within the physiological range. The B-cells of the pancreatic islets show hypergranulation. Functional tests of the blood pressure under exercise load, and of blood sugar under glucose load revealed normal reactions in animals with hippocampal lesions. In animals with intact brains the same stress exposure caused pathologic malfunctioning (under learning stress) or even premorbid states. The results being considered in relation to the pathogenesis of arterial hypertension show that the exclusion of circumscribed areas of the hippocampus prevents the development of permanent, stress-induced emotional excitations spreading into the viscerum.

Animals↗
PubMed1976

[Learning and chronobiological regulation following experimental damage to the coronary-artery wall of albino rats].

Forty male albino rats were used to study the relationship between experimentally (concentrated hydrochloric acid) produced local structural changes of the coronary artery wall and central nervous information processing and chronobiological events, respectively. The alterations of the coronary arteries caused by this treatment did not produce infarction but initiated on the whole length of the arterial branch proliferative processes that are complete within 12 weeks following the intervention. Central nervous information processing and chronoregulatory processes showed, immediately after exposure to hydrochloric acid, pronounced malfunctions followed by a stage of hyperreactivity (4 weeks following the damage). At 8 weeks from the intervention, the parameters of information processing and chronobiological events of the CNS again equalled the control values. Since the central nervous functions were back to normal earlier than the structural alterations, the results are interpreted as reflecting CNS-controlled interactions between the complex of visceral afference and efference, the regulation of which is determined by the CNS after coronary damage in such a way as to restore the adaptational capacity of the organism by a predominance of sanogenetic processes.

Animals↗
PubMed1976

Insulin kinetic, glucose tolerance, and lipid metabolism in genetically spontaneous-hypertensive rats.

Genetically spontaneous hypertension in rats (SHR) showed a significant rise not only in systolic blood pressure in the early age groups, but also, from the 8th week of life onward, in diastolic blood pressure together with a rise in heart rates, when compared with control rats. Following an i.p. glucose injection a disturbed glucose tolerance, increased insulin level and a reduction in plasma triglycerides and cholesterol occurred. These findings in SHR allow to draw interesting analogous conclusions as to the protodiabetic disturbances in carbohydrate metabolism accompanied by insulin enhancement after glucose and diminished glucose- and increased lipogenetic effects, which had been demonstrated by R. BAUMANN et al. in 58% of all studied cases of juvenile human hypertension (Stage I and Stage II, NITSCHKOFF and R. BAUMANN), in which possibly hereditary factors may be involved.

Animals↗