Glycosaminoglycan content in tissues and body fluids of rats treated with atherogenic diet.

An increase of total glycosaminoglycan content in aortic wall and liver as well as changes in the concentration of glycosaminoglycan fractions in aorta, skin, liver, and blood serum were found in white rats fed with atherogenic diet. Urinary excretion of glycosaminoglycans was increased in experimental animals.     

Insulin and beta receptor modulation of K homeostasis in nephrectomized dogs with hyperkalemia

In nephrectomized dogs infused with 2 mEq KCl/kg/hr a homeostatic mechanism retards the development of hyperkalemia by transferring about 70% of the K load to intracellular fluid. beta Adrenergic receptor activity is importantly involved in the transfer process; halting it with propranolol reduces the proportion transferred to less than 35%. The addition of pancreatectomy increases the involvement of beta receptor activity; propranolol treatment now reduces the proportion transferred to less than 20%. Insulin treatment, on the other hand, not only improves transfer of a K load, it also alters the response to propranolol. Nephrectomized dogs treated with 2 U insulin/kg/hr deposit some 80% of the infused K in intracellular fluid. After beta receptor blockade, nearly 90% is transferred. The results suggest that in the K homeostatic mechanism of nephrectomized dogs, insulin and beta receptors may be reciprocally related. K transfer mediated by beta receptors improves after pancreatectomy, and insulin mediated K transfer improves after beta receptors are inactivated.     

Changes in anthocyanin and phenolics content of grapevine leaf and fruit tissues treated with sucrose, nitrate, and abscisic Acid

Sucrose (0.04 to 0.12 m) induces accumulation of both total phenolics and anthocyanin in leaf discs of grapevine (Vitis vinifera L.) incubated in intermittent light. Abscisic acid (20 muM) and 2-chloroethyl phosphonic acid (60 mum) act synergistically with the sucrose to enhance its induction of both total phenolics and anthocyanin. The magnitude of this interaction depends on leaf age. Nitrate (30 mm) inhibits sucrose induction of phenolics and anthocyanin. Levels of total phenolics and anthocyanin changed independently.     

Adrenal cortex, tumor, and peripheral production of deoxycorticosterone.

A method is reported for the measurement of the urine excretion rates of tetrahydro-11-deoxycorticosterone (3 alpha,5 beta-THDOC), an important metabolite of 11-deoxycorticosterone (DOC). Quantification using gas chromatography/mass spectrometry (GC/MS) was achieved by comparing the ion fragment response for the molecular ion (m/z 507) of the analyte (as methyloxime trimethylsilyl ether derivative) to that of a fixed amount of an isomer of THDOC added to urine as internal standard. To improve the specificity of measuring THDOC in clinical samples, an additional Sephadex LH-20 chromatography step was introduced to separate 11-deoxycortisol and some progesterone metabolites. In the luteal phase of the menstrual cycle, THDOC excretion was higher than in the follicular phase; it was also higher than in women taking oral contraceptives. The correlation of THDOC with progesterone production, independent of a constant cortisol output, supports an ovarian or peripheral conversion of progesterone to DOC. The assay proved useful (1) in monitoring for the recurrence of a mineralocorticoid-secreting tumor and (2) when adrenal production of DOC was not fully suppressed in congenital adrenal hyperplasia due to 11 beta-hydroxylase deficiency. Under the latter circumstances, the renin-angiotensin system seemed to be an important regulator of DOC production.     

Changes in polyamines,proline and ethylene in sunflower calluses treated with NaCl

Responses of sunflower tissues to NaCl stress were studied in control (C), salt-stressed (S) and salt-adapted (T) calluses in terms of proline, polyamines and ethylene content for a period of 21 days. Salt-adapted calluses showed their adaptation to salinity by growing in the medium with 175 mM NaCl, at a similar rate than C calluses on medium without salt. Proline concentration was 27 times higher in salt-adapted calluses compared to control calluses at time 0, but salt stressed calluses (S calluses) were able to increase proline by day 21, demonstrating that proline was not just an osmoregulator but might be involved in other responses in sunflower salt-stressed calluses. Putrescine (Put) was the most abundant polyamine in C calluses at time 0, while spermidine (Spd) was the main polyamine in salt tolerant (T) calluses. Ethylene increased in C calluses until day 14, decreasing thereafter. In salt-adapted calluses, ethylene increased significantly over the concentration in C and S calluses by the end of the experiment. In control calluses, the highest level of total polyamines and the lowest of ethylene was found on day 21, while T calluses synthesized the highest ethylene level and had the lower polyamines level by this time. It seems that in salt-adapted calluses ethylene was related to stress tolerance and in salt sensitive tissues (S calluses), ethylene formation was related to senescence. The present data suggests a close relationship between proline, polyamines, ethylene and salt-stress tolerance in sunflower dedifferentiated tissues.