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Biomedical subjects

Y Gutman

Publications and source records attributed to Y Gutman.

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

The effect of saline loading on blood pressure and catecholamine secretion in the rat and the cat.

The effects of acute and chronic saline loading on blood pressure and catechalomine (CA) response in the rat and cat were studied. In the rat, both acute and chronic saline loading stimulated urinary CA excretion without affecting blood pressure; adrenal tyrosine hydroxylase (TH) activity was increased. Pentolinium bitartrate abolished the increase in CA excretion. Chronic saline loading reduced the plasma renin concentration (PRC) and the heart noradrenaline concentration and elevated the plasma cholesterol. Acute infusion of isotonic or hypertonic saline in the cat stimulated adrenomedullary CA secretion. This response was not significantly affected after bilateral cervical vagotomy, but was totally abolished following bilateral nephrectomy. Blood pressure was increased only during the isotonic saline infusion but not during hypertonic saline administration. It is concluded that stimulation of adrenal CA secretion by saline loading is mediated through a renal factor.

Animals↗
PubMed1979

Effects of verapamil, dantrolene and lanthanum on catecholamine release from rat adrenal medulla.

1. The release of catecholamines (CA) from rat adrenal incubated in vivo in Locke solution was studied. 2. Acetylcholine-induced release of CA and CA release by 56 mM KCl were inhibited by verapamil and lanthanum chloride which block calcium permeability. 3. CA secretion induced by salbutamol or by theophylline was unaffected by either verapamil or lanthanum chloride. 4. Dantrolene-sodium inhibited the CA secretion induced by theophylline but only partially reduced potassium-induced release of CA. 5. Verapamil enhanced the secretion of CA induced by salbutamol (in a calcium-free medium). 6. Tyramine-induced secretion of CA was unaffected by lanthanum chloride, verapamil or dantrolene-sodium. 7. It is suggested that cyclic adenosine 3',5'-monophosphate-mediated CA secretion (induced by theophylline or salbutamol) depends on release of calcium from intracellular stores, and that CA secretion induced by tyramine is independent of intra- or extracellular calcium.

Adrenal Medulla↗
PubMed1979

The use of phospholipid liposomes for lithium administration. Polydipsic effect and tissue distribution of lithium.

Administration of lithium entrapped in phospholipid liposomes increased the lithium-induced polydipsia, but did not accelerate the onset of this effect. It also resulted in a larger accumulation of lithium in the liver, kidney and spleen, but not in the brain. The time course of polydipsia suggests that it depends on the intracellular lithium concentration. However, the rate of development of this effect depends on some additional factor.

Animals↗
PubMed1979

Drug uptake into everted intestinal sacs. I. Enhancement by hypertonicity.

The transfer of the cationic drugs, pralidoxime (PAM) and tetraethylammonium, and anionic ampicillin from the mucosal-to-serosal sides of everted rat jejunal sacs is enhanced by mucosal hypertonicity. PAM uptake, which is proportional to initial mucosal concentrations up to 2.3 mM, is enhanced by mucosal hypertonicity due to addition of sodium, potassium, lithium and choline chloride, sodium sulfate, and the nonionic solutes, urea, sucrose, and mannitol. Bicarbonate, Tris, or phosphate buffer and the presence of magnesium and calcium do not affect this hypertonicity-induced acceleration of PAM passage. Serosal osmolality has no effect on transfer and mucosal hypertonicity is equally effective in the presence and absence of a transmural osmotic gradient. This observation and minimal changes in the concentration of inulin placed in the sacs suggest that fluid shifts and solvent drag are not responsible for the enhanced mucosal-to-serosal transfer of PAM from hypertonic buffer. Mucosal hypertonicity at 450 mosmol/kg causes reversible enhancement of PAM transfer, whereas the effect of 600 mosmol/kg cannot be reversed by replacing the tissue in isotonic buffer. The effect of osmotic manipulation on PAM transfer across the intestine thus differs from its effect on the passage of other ionized species and drugs across other epithelia.

Ampicillin↗
PubMed1978

Angiotensin II mediation of adrenal catecholamine secretion induced by intrarenal isoprenaline infusion.

Isoprenaline infusion into the renal artery of the cat induced an increase in the catecholamine (CA) secretion rate from the adrenal gland. CA release by isoprenaline was preferentially noradrenaline. Intravenous infusion of an angiotensin II (A II) antagonist abolished adrenal CA response to intrarenal isoprenaline injection. It is suggested that intrarenal isoprenaline infusion stimulates renal renin release and A II production which, in turn, stimulates adrenal CA secretion.

Adrenal Glands↗
PubMed1978

Effect of indomethacin on water intake of the rat.

Indomethacin stimulated water intake in intact rats. This effect could also be demonstrated in bilaterally ureteral ligated rats, but it was totally abolished after bilateral nephrectomy. It is suggested that the stimulatory effect of indomathacin on water consumption is mediated by a renal factor.

Animals↗
PubMed1978

Hypertension and brain catecholamine distribution in the Hebrew University Sabra, H and N rats.

1. The concentration of catecholamines was measured in several brain areas of the Hewbrew University Sabra rat (SB rat), and in two substrains selected for their respective sensitivity (H) or immunity (N) to hypertension. 2. Hypertension was induced in SB rats by DOCA-salt, renal artery constriction and NaCl 1.7% drinking. The noradrenaline content was consistently elevated in the medulla oblongata of hypertension animals. In other brain areas the rise in noradrenaline varied in the different types of hypertension. 3. Administration of DOCA-salt to H and N rats, while causing marked hypertension in the former, had no effect on noradrenaline in either strain. 4. Untreated, normotensive N rats had in the medulla oblongata, significantly higher concentrations of noradrenaline than did H rats. 5. Differences in brain noradrenaline may explain the inherited susceptibility or resistance to hypertension in H and N rats.

Animals↗
PubMed1977

Opposite effect of PGE2 on cAMP levels in human adrenal medulla and pheochromocytoma.

PGE2 (10(-7) M) caused increased cAMP accumlation in 5 pheochromocytomas, while in 3 human adrenal medullae PGE2 caused a significant decrease of cAMP level on incubating slices in vitro. This finding is discussed in relation to the opposite effect of PGE2 on catecholamine release from human medulla and pheochromocytoma slices in vitro.

Adrenal Gland Neoplasms↗
PubMed1977

Renin-angiotensin mediation of adrenal catecholamine secretion induced by haemorrhage.

The mechanism involved in catecholamine (CA) release from cat adrenal gland, in response to haemorrhage was studied. In intact cats, in cats with bilateral cervical vagotomy or following bilateral ureteral ligation, haemorrhage induced an increased catecholamine release from the adrenal (with increased percentage of noradrenaline). Acute bilateral nephrectomy, chronic sodium loading with repeated administration of desoxycorticosterone acetate (DOCA), or acute denervation of the adrenal gland, completely abolished the increased CA release from the adrenal gland following haemorrhage. Haemorrhage induced an increase of plasma renin concentration in intact cats and after ureteral ligation but there was no increase in plasma renin after haemorrhage in cats with bilateral nephrectomy or following pretreatment with DOCA and salt load. Following haemorrhage in intact cats, blood pressure showed an immediate fall followed by rapid recovery. The recovery of blood pressure after haemorrhage was abolished in cats with bilateral nephrectomy. It is concluded that the adreno-medullary response to haemorrhage in the cat, depends primarily on the intact renal renin angiotensin system. Angiotensin, generated peripherally, probably affects the CNS and activates the sympathetic nerves.

Adrenal Glands↗