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Biomedical subjects

P L Sharma

Publications and source records attributed to P L Sharma.

At least 127 records · Page 7Linked to original sources
PubMed1981

Enhancement of detrusor reflex activity by naloxone in patients with chronic neurogenic bladder dysfunction. Preliminary report.

An intravenous injection of 0.4 mg. naloxone enhanced detrusor reflex activity in 5 patients with chronic neurogenic bladder dysfunction caused by incomplete suprasacral spinal lesions. The intravesical volume at which detrusor reflex occurred showed a decrease from 498.2 to 346.2 ml. The naloxone-induced effect was short-lived, being absent 1 hour after the injection. In the same dosage naloxone did not induce detrusor reflex in 2 patients with areflexic bladder caused by complete suprasacral spinal lesions.

Adolescent↗
PubMed1981

Effect of ovulation on the response of the rabbit oviduct to acetylcholine in vitro.

Acetylcholine had a stimulatory effect on both the longitudinal and circular isthmi of the rabbit fallopian tube in vitro. The longitudinal isthmus was more responsive than the circular isthmus. The stimulatory effect was blocked by phentolamine (3 x 10(-7) M). The oviduct obtained from animals sacrificed 24 h after human chorionic gonadotropin (hCG) administration was more responsive to acetylcholine as compared to the oviduct obtained 72 h after hCG and from animals without ovulation induction. The maximum isometric tension developed was greater in tissues obtained from animals sacrificed 24 h after hCG. The results of this study suggest that the effect of acetylcholine may be partly mediated through the release of noradrenaline and may have a functional role in the regulation of ovum transport.

Acetylcholine↗
PubMed1980

Neuromuscular blocking action of sodium nitroprusside alone and with d-tubocurarine.

The effect of sodium nitroprusside (SNP) per se on neuromuscular transmission and its effect on the action of d-tubocurarine (d-Tc) was studied in rabbits and rats. SNP produced a dose-dependent neuromuscular block which was not significantly antagonized by physostigmine. The tetanic response to nerve stimulation was not affected. Pretreatment with SNP significantly increased the intensity and the duration of action of d-Tc. The probable mechanism involved in SNP-induced neuromuscular blockade is discussed.

Animals↗
PubMed1980

Clinical import of beta-adrenergic activity in the proximal urethra.

Beta-adrenergic activity of the proximal urethra was studied in 11 patients. Maximum urethral pressure was recorded before, and 20 and 60 minutes after the intravenous administration of 0.5 mg. orciprenaline sulfate. There was a 40 per cent or more decrease in the maximum urethral pressure in 6 of the 11 patients. Beta-adrenoreceptor agonists could prove useful in facilitating vesical emptying by reducing urethral resistance in patients with neurogenic bladder dysfunction.

Adolescent↗
PubMed1980

Experimental myocardial infarction in rhesus monkeys. Verapamil pretreatment in the reduction of infarct size.

An experimental model of acute myocardial infarction has been created in the rhesus monkey by surgical ligation of the anterior descending branch of the left coronary artery. The effect of verapamil on the size of myocardial infarct was investigated. Four groups of experiments were carried out. Group I animals served as operated controls. In group II, verapamil (Isoptin) was administered intravenously half an hour after coronary ligation and repeated every 6 hr for 24 hr. Group III animals were given verapamil orally in the dosage of 4 mg/kg, three times a day, 10 days before coronary ligation. In group IV, the chest was opened by the coronary artery was not ligated (sham-operated group). The infarct size was measured 5 days after coronary ligation by the histochemical technique of nitro-blue tetrazolium staining. The size of the infarct amounted to 22.05% +/- 1.34% of the left ventricular weight in group I, 19.40% +/- 2.08% in group II, and 14.08% +/- 1.26% (P < 0.01) in group III. No infarct was detected in group IV monkeys.

Administration, Oral↗
PubMed1980

Effect of imidazole on oxytocin and acetylcholine induced responses in isolated rat uterus: with observations on its mechanism of action.

Imidazole (3.67 x 10(-3) M) and sodium bicarbonate (1.78 x 10(-2) M) failed to alter acetylcholine evoked responses in isolated rat uterus but they produced a significant shift of the log dose-response curve of oxytocin to the left. This potentiating effect was reversible. Addition of imidazole increased the pH of de Jalon solution from 7.2 to 8.5. Sodium dihydrogen orthophosphate (3.3 x 10(-3) M) prevented the change of pH due to the addition of imidazole and at the same time the potentiating effect of imidazole was inhibited. The present study strongly suggests that the potentiation of oxytocin-evoked responses by imidazole is due to the change in pH of de Jalon solution towards more alkaline range and it may not be due to stimulation of phosphodiesterase activity of rat uterus.

Acetylcholine↗
PubMed1980

Further observations on vesicourethral dopamine receptors--a urodynamic study with haloperidol.

The effect of intravenous administration of 5 mg of haloperidol, a dopamine receptor antagonist upon cystometry, the urethral pressure profile, and the external urethral sphincter electromyography (EMG) was investigated in eight patients with neurogenic vesical dysfunction. There was no change in the detrusor reflex or in the sphincter EMG activities, but the peak urethral pressure decreased. The possible reasons for the difference in the above result as compared to our previous study using metoclopramide, another dopamine receptor antagonist, are discussed.

Adolescent↗
PubMed1979

Effect of estradiol and progesterone on the isometric tension developed by longitudinal and circular isthmus of rabbit fallopian tube.

The effect of estradiol and progesterone on the isometric tension developed by longitudinal and circular muscle of isthmus of rabbit fallopian tube to various agonists was studied. The isometric tension developed was reduced by about 50% under progesterone dominance as compared to estrogen dominance. This inhibition was of non-specific nature and did not involve adrenergic receptors. The non-specific effect of progesterone may have a role in regulating the entry of ova into the isthmus after their initial retention at the ampullary--isthmic junction.

Animals↗
PubMed1979

Relationship between concentration of prostaglandins E and F in the regulation of ovum transport in rabbits.

Prostaglandin E and F levels were measured by a radioimmunoassay technique in different parts of the rabbit fallopian tube treated with indomethacin and in untreated rabbit at 0, 24, 48 and 72 hours after Human Chorionic Gonadotrophin (HCG) administration. The results indicate a significant rise in the levels of PGE and fall in the levels of PGF throughout the isthmus at 48 hours and in the distal isthmus at 72 hours in the untreated rabbits. In the indomethacin treated rabbits, PGF levels were reduced relatively more than PGE levels in different parts of the rabbit fallopian tube at various time intervals after HCG administration. Prostaglandins E and F may have a role in regulating ovum transport.

Animals↗
PubMed1979

Effect of glucocorticoids on cardiovascular reactivity in rats subjected to haemorrhagic shock.

The effect of glucocorticoids on the cardiovascular responses evoked by catecholamines and angiotensin in haemorrhagic shock was investigated in rats. In the intact preparation, cardiovascular responses to adrenaline, noradrenaline and angiotensin immediately after induction of haemorrhage improved the pressor responses of all the three pressor agents but it was ineffective when given in late stages of shock. Prednisolone and betamethasone improved selectively more the adrenaline responses. Treatment with all the three glucocorticoids improved the pressor responses evoked by noradrenaline and isoprenaline in isolated perfused hind-quarters of the rat but the pressor response evoked by adrenaline was only potentiated by prednisolone and betamethasone treatment. Glucocorticoid treatment in early stages prevented only the impairment of inotropic responses but did not improve the chronotropic responses in the isolated perfused heart of rat. The present study confirms the clinical observation that glucocorticoids prove beneficial only if administered in early stages of shock, and that this may be due to (i) prevention of the peripheral vasoconstrictor action of vasoactive substances such as catecholamines and angiotensin (released in shock) and (ii) prevention of the release of toxic factors such as a myocardial depressant factor.

Angiotensin II↗