PubMed Health⌕ Search

Biomedical subjects

J Krecek

Publications and source records attributed to J Krecek.

At least 37 records · Page 2Linked to original sources
PubMed1979

Effect of age on hypertensive stimuli and the development of hypertension in Brattleboro rats.

1. In rats with inherited diabetes insipidus, unilateral nephrectomy plus drinking of 0.6% NaCl solution (saline) did not influence blood pressure in adult rats. However, when these factors applied before puberty, they produced hypertension. 2. We therefore analysed whether saline administration before puberty or unilateral nephrectomy before puberty was more important for this hypertensive response. 3. Saline drinking was found to be necessary for the response because hypertension was elicited by unilateral nephrectomy in adult rats only if saline consumption began before puberty.

Aging↗
PubMed1978

Effect of ovarectomy of females and oestrogen administration to males during the neonatal critical period on salt intake in adulthood in rats.

The effect of interference in the neonatal critical period on water and salt solution (3% NaCl) intake by adult rats given a free choice of these fluids was studied. Consumption was expressed per animal, per 100 g body weight and as the NaCl concentration in the total daily fluid intake volume [NaCl]I. Newborn female rats were ovarectomized or sham-ovarectomized. Ovarectomy markedly reduces consumption and [NaCl]I in adulthood and brought these values close to the values in normal males. Newborn male rats were injected with 1 mg oestradiol propionate dissolved in oil or just with oil. Oestradiol propionate severely inhibited growth, but produced no changes in fluid intake per animal. The [NaCl]I values were likewise unaltered, but owing to the lower body weight comsumption values per 100 g b.w. were higher in rats given oestradiol propionate than in those given oil. The relationship of the given growth changes to the regulation of salt intake and to hypothalamic function and its sexual correlates is discussed.

Animals↗
PubMed1977

Hypertension in rats with hereditary diabetes insipidus. The role of age.

The effect of age, sex and salt intake on the hypertension produced in homozygous (DI) and heterozygous (non-DI) Brattleboro rats and Long Evans rats was studied. The left kidney was removed at the age of 25, 35, 50 and 80 days (UNX 25, UNX 35, UNX 50, UNX 80), and 0.6% NaCl solution or water was offered as drinking fluid. In UNX DI rats drinking saline the mean value of blood pressure (BP) exceeded 150 torr. The highest values of BP were observed in DI UNX 25 females while no hypertension occurred in rats UNX 80. There was no correlation between individual values of BP and saline consumption in DI females with hypertension. However, individual BP values correlated with the urinary Na+/K+ ratio measured in the course of 24 h of water deprivation, due to age-dependent sodium excretion the values of which were highest in the UNX 25 group. Hydronephrosis was present in all DI rats with manifest hypertension. In hypertensive animals, BP values, Na+/K+ ratio and the frequency of hydronephrosis exhibited the same age dependence. The role of age and adaptability to the increased saline intake in the susceptibility of DI rats to experimental hypertension is discussed.

Age Factors↗
PubMed1977

Blood pressure and water and electrolyte intake and excretion in rats (Brattleboro strain) after unilateral nephrectomy.

Using Brattleboro rats with and without hereditary diabetes insipidus (DI, non-DI), blood pressure, water intake and the excretion of water, sodium, potassium and osmotically active substances were measured in intact individuals and in animals subjected to unilateral nephrectomy at the age of 23 or 80 days. The development of blood pressure (BP) changes, determined in unilaterally nephrectomized animals at the age of 4--6 months, depended on the age at which the kidney was removed. After nephrectomy at the age of 25 days, hypertension developed only in DI females given 0.6% NaCl solution to drink. The BP of those which drank water was unaffected. Unilateral nephrectomy at the age of 80 days produced a slight BP increase in females irrespective of whether they drank water or 0.6% NaCl, but in males only if they drank 0.6% NaCl solution. No hypertension was observed in intact animals. No relationship was found between water intake and the blood pressure level. The BP increase in water-drinking females uninephrectomized at 80 days was accompanied by a raised urine flow and raised excretion of osmotically active substances. Sodium losses in DI animals were greater than in non-DI animals and the urinary sodium concentration, in maximum dehydration, attained minimum values in DI and maximum values in non-DI animals. Unilateral nephrectomy at 25 days increased sodium losses in all the animals except non-DI females, but when performed at 80 days, only in DI males. No relationship between these results and BP changes was found. The possible relationship of the extrarenal consequences of absence of vasopressin to the development of experimental hypertension are discussed.

Animals↗
PubMed1976

The pineal gland and the development of salt intake patterns in male rats.

The effect of gonadectomy, sham-gonadectomy, pinealectomy, and sham-pinealectomy on the concentration of NaCl in the total volume of fluid drunk per day ([NaCl]) in male rats offered a free choice between water and 3% saline was measured. Neonatal gonadectomy increased [NaCl] I in adult males but had no effect on immature rats. If the rats, however, were neonatally pinealectomized as well as gonadectomized, the increase of [NaCl] I also appeared in the immatures. Neonatal sham-pinealectomy decreased [NaCl] I in immature and adult rats, both gonadectomized and sham-gonadectomized. In adult neonatally gonadectomized males the effects of sham-pinealectomy did not occur in those animals actually pinealectomized. The role of the pineal gland in the regulation of water and salt intake is discussed in relation to the function of hypothalamus, neonatal stress, and sexual maturation.

Age Factors↗
PubMed1975

The pineal gland and the effect of neonatal administration of androgen upon the development of spontaneous salt and water intake in female rats.

The effect of pinealectomy (PX) and sham-pinealectomy (SPX) on the calculated concentration of NaCl in the total volume of fluid drunk per day ([NaCl]I) in female rats offered a free choice between water and 3% NaCl solution was measured. In normal rats the [NaCl]I increases after attainment of sexual maturity. The increase can be accelerated by neonatal PX. Neonatal 'masculinization' of female rats by testosterone propionate (TP2) removes the increase of [NaCl]I in adult females and suppresses the acceleration due to PX. Neonatal SPX interferes with this decreasing effect of TP2 in adult female rats. The role of the pineal gland in the regulation of water and salt intake is discussed in relation to sex differences, sexual maturation and neonatal stress.

Animals↗
PubMed1975

[Axolotl 1975].

Explore the source record for details and available documents.

Ambystoma↗